A new cable anchoring system and its design method

Abstract

The application relates to the field of cable anchoring, in particular to a novel cable anchoring system and a design method thereof. The novel cable anchoring system comprises an anchor cup, the anchor cup is provided with a through main anchor cavity, one end of the main anchor cavity is provided with a front end hole, the other end of the main anchor cavity is provided with a rear end hole, the aperture of the rear end hole is larger than that of the front end hole, the inner wall of the main anchor cavity is provided with at least two secondary circular table surfaces, the inner diameter of the secondary circular table surfaces gradually increases from the front end to the rear end, a stepped transition surface is arranged between the adjacent secondary circular table surfaces, the inner side of the stepped transition surface is inclined towards the front end hole, and the inner diameter of the secondary circular table surface on the front side of the stepped transition surface is smaller than that of the secondary circular table surface on the rear side. The novel cable anchoring system can effectively reduce the peak stress level of the anchor cup and the cast body as a whole through the stepped transition surface and the secondary circular table surface, can make the stress distribution of the inner surface of the anchor cup more uniform and reasonable, can reduce the slip deformation of the cast body, and can improve the static performance and fatigue performance of the anchoring system.

Description

Technical Field

[0001] This invention relates to a cable, and more particularly to a novel cable anchoring system and its design method. Background Technology

[0002] Cables are the lifeline of cable-stayed bridges, and anchor cups are an indispensable and important component of cable strands, serving to connect, anchor, and transmit forces. The axial force of the cable is entirely transmitted to the anchorage through the anchor cups; therefore, the anchoring performance and stress condition of the anchor cups are crucial to the safety of the cable strands.

[0003] As the strength of steel wire materials in bridge cables continues to increase, the tensile force of the cable strands is also constantly rising, leading to increasingly stringent requirements for the reliability and durability of anchor cups. However, conventional cable anchor cup structures are prone to problems such as excessively high local stress peaks, excessive deformation, decreased anchoring efficiency, and insufficient fatigue performance when subjected to higher levels of tensile loads, making it difficult to meet the anchoring requirements of high-strength cables. Simply increasing the geometric dimensions of conventional anchor cups is no longer sufficient to meet practical engineering needs; therefore, there is an urgent need to develop bridge cable anchor cup structures with high fatigue resistance and strength matching.

[0004] To address the aforementioned challenges, patent (publication number: CN113802455A) discloses an anchor cup for carbon fiber parallel cables and its anchoring method. This method primarily involves setting multiple secondary frustum surfaces, and when the cone angle of the secondary frustum surface is greater than that of the original surface, it exhibits an inward concave shape. This mainly provides additional radial constraint by enlarging the cone angle of the secondary frustum surface, but its effectiveness is limited in practical applications. Summary of the Invention

[0005] The purpose of this invention is to overcome the problem in the prior art that the additional radial constraint provided by enlarging the cone angle of the secondary frustum surface has limited effect in practical use, and to provide a novel cable anchoring system and its design method.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] A novel cable anchoring system includes an anchor cup, wherein: a through main anchor cavity is provided on the anchor cup, with a front end hole at one end and a rear end hole at the other end; at least two secondary frustum surfaces are sequentially provided on the inner wall of the main anchor cavity along the through direction of the main anchor cavity, so that the main anchor cavity forms at least two frustum anchor cavities, and a stepped transition surface is provided between adjacent secondary frustum surfaces; along the direction from the front end hole to the rear end hole, the inner diameter of the secondary frustum surface and the inner diameter of the stepped transition surface both increase.

[0008] This application describes a novel cable anchoring system where, along the direction from the front end hole to the rear end hole, the inner diameters of both the secondary frustum surface and the stepped transition surface increase. This results in the inner diameter of each secondary frustum surface near the front end hole being smaller than the inner diameter of the other end. When the casting moves relative to the anchor cup towards the front end hole or has a tendency to move relative to it, the casting abuts against the stepped transition surface and the secondary frustum surface. In addition to the axial bearing capacity provided by the secondary frustum surface, the stepped transition surface provides additional axial bearing capacity. Simultaneously, each level of the secondary frustum surface can provide both axial and radial bearing capacity. This novel cable anchoring system, through the combination of the stepped transition surface and the secondary frustum surface, effectively reduces the peak stress level between the anchor cup and the casting, making the stress distribution on the inner surface of the anchor cup more uniform and reasonable, and reducing the slip deformation of the casting, thereby improving the static and fatigue performance of the anchoring system.

[0009] Preferably, at least two adjacent surfaces of the secondary frustum are parallel to facilitate the manufacture of the anchor cup.

[0010] Preferably, the surface length of the secondary frustum is greater than the length of the transition surface between adjacent steps.

[0011] Preferably, the surface of the secondary frustum transitions continuously with the transition surface of the adjacent step.

[0012] Preferably, the inner diameter of the secondary frustum surface gradually increases in the direction from the front end hole to the rear end hole.

[0013] Preferably, the inner diameter of the stepped transition surface gradually increases along the direction from the front end hole to the rear end hole.

[0014] Preferably, the surface of the secondary frustum is roughened.

[0015] Preferably, the surface of the secondary frustum is provided with pits.

[0016] Preferably, the surface of the secondary frustum is provided with protrusions.

[0017] Preferably, the step transition surface is provided with a recessed portion.

[0018] Preferably, a first protrusion is provided on the transition surface of the step.

[0019] Preferably, the bottom of the recess is inclined toward the front end hole.

[0020] Preferably, the axial section line of the secondary frustum surface is a straight line, a circular curve, an elliptic curve, a power function curve, an exponential function curve, a hyperbola, or a spiral.

[0021] Preferably, the novel cable anchoring system described in this application further includes steel wire strands, the main anchor cavity is filled with a casting, the casting is in contact with the surface of the secondary frustum and the step transition surface, the steel wire strands pass through the front end hole, and at least a portion of the steel wire strands are located in the casting.

[0022] This application discloses a novel cable anchoring system. During installation and use, the ends of the steel wire strands are passed through the front end hole and then split into multiple strands. The main anchor cavity of the anchor cup is filled with a casting to fix the separated strands. The diameter of the rear end hole is larger than that of the front end hole. The inner diameter of the secondary frustum surface gradually increases along the direction from the front end hole to the rear end hole. A stepped transition surface is provided between adjacent secondary frustum surfaces. The inner side of the stepped transition surface is inclined towards the front end hole. The inner diameter of the secondary frustum surface on the side of the stepped transition surface closer to the front end hole is smaller than that on the side of the stepped transition surface farther from the front end hole. It can be concluded that the diameter of each secondary frustum surface near the front end hole is smaller than the diameter of the other end, and the diameter value is between the diameter of the front end hole and the diameter of the rear end hole. When the steel wire... When the strand is under tension, the steel wire can drive the casting to move relative to the anchor cup towards the front end hole, or has a tendency to move relative to it. At this time, the casting can abut against the stepped transition surface, and provide additional axial bearing force through the stepped transition surface between several secondary frustums. At the same time, since the inner diameter of the secondary frustum surface on the side of the stepped transition surface closer to the front end hole is smaller than the inner diameter of the secondary frustum surface on the side of the stepped transition surface farther from the front end hole, the secondary frustum surfaces at each level can provide the combined effect of axial bearing and radial bearing. The novel cable anchoring system described in this application, through the step transition surface and the secondary frustum surface, the multi-stage frustum anchor cavity structure can effectively reduce the peak stress level of the anchor cup and the casting, make the stress distribution on the inner surface of the anchor cup more uniform and reasonable, and reduce the slip deformation of the casting, thereby improving the static performance and fatigue performance of the anchoring system.

[0023] Preferably, a wire guide sleeve is further provided inside the main anchor cavity. The wire strands pass through the wire guide sleeve, and the portion of the wire strands located between the wire guide sleeve and the rear end hole is split into at least three wires. The inner wall of the wire guide sleeve has a continuously changing curvature along the opening direction of the wire guide sleeve. The portion of the inner wall of the wire guide sleeve near the front end hole is smoothly tangent to the outer wall of the corresponding portion of the wire strands. The portion of the inner wall of the wire guide sleeve near the rear end hole is smoothly tangent to the outermost layer of wire strands after splitting.

[0024] In conventional anchoring systems, the steel wires are tightly packed when entering the small end of the anchor cup. However, at the large end of the anchor cup, due to the wire separating plate, the starting and ending points of each wire are defined. This results in the wires forming a zigzag pattern within the anchor cup, with angles at the small end, making this area prone to fatigue fracture under cyclic loading. This application addresses this by incorporating a wire guide sleeve. The purpose is to ensure that the outermost wires in the wire strand transition along the curve of the inner wall of the guide sleeve when unwinding, while the inner wires transition along the curve of the adjacent outer wires. This effectively avoids at least most of the wire angles and significantly improves the fatigue resistance of the wires in this area.

[0025] Preferably, the wire guide sleeve is arranged in a trumpet shape.

[0026] Preferably, in the cross-sectional direction of the wire guide sleeve, the inner wall of the wire guide sleeve is polygonal in shape.

[0027] Preferably, along the opening direction of the wire guide sleeve, the shape of the cross-sectional line of the inner surface of the wire guide sleeve includes a circular curve, an elliptical curve, a power function curve, an exponential function curve, a hyperbola, or a spiral.

[0028] Preferably, the wall thickness of the anchor cup gradually increases from the free end to the loaded end. The free end is the larger opening, and the loaded end is the smaller opening. The wall thickness of the anchor cup gradually increases from the larger opening to the smaller opening, which improves the stress distribution of the anchor cup.

[0029] Preferably, the diameter of the rear end hole is larger than the diameter of the front end hole.

[0030] Preferably, the anchor cup can be used for main cables, suspenders, or stay cables.

[0031] This application also discloses a design method for the novel cable anchoring system described in this application, comprising the following steps:

[0032] S1. Determine the position of the main anchor cavity surface based on the diameter of the front end hole and the diameter of the rear end hole;

[0033] S2. Determine the surface length of each secondary frustum segment;

[0034] S3. Determine the end position of the secondary frustum surface near the front end hole based on the length of the secondary frustum surface and the position of the main anchor cavity surface;

[0035] S4. Determine the angle between the surface of the secondary frustum and the surface of the main anchor cavity;

[0036] S5. Determine the angle of the step transition surface relative to the secondary frustum surface based on the angle of the secondary frustum surface relative to the main anchor cavity surface.

[0037] This application also discloses another design method for novel cable anchoring systems, comprising the following steps:

[0038] A1. Analyze the impact of stress distribution results from the reference model of the cable anchoring system on the performance of the anchor cup and the casting;

[0039] A2. Combine the key parameters of the anchor cup to form multiple combined models;

[0040] A3. Based on the analysis of each combination model, at least some key parameters are used to determine the stress distribution and stress peak value of the anchor cup and the casting, and the influence law of the key parameters is determined.

[0041] A4. Based on the influence of each key parameter, optimize the anchor cup, casting body and steel wire to form the new cable anchoring system model;

[0042] A5. Evaluate and analyze the improvement effect of the novel cable anchoring system model on fatigue resistance compared with the baseline model of the cable anchoring system.

[0043] This application describes a design method for a novel cable anchoring system. The method analyzes the impact of stress distribution results from a baseline model of the cable anchoring system on the performance of the anchor cup and casting. Key parameters of the anchor cup are combined to form multiple combined models. Based on each combined model, the stress distribution and peak stress of at least some key parameters on the anchor cup and casting are analyzed to determine the influence of these key parameters. Optimization directions are identified, and the anchor cup, casting, and steel wire are then optimized. The improved fatigue resistance of the optimized novel cable anchoring system is then confirmed through improvements in fatigue performance, resulting in optimized stress distribution in the anchor cup, casting, and steel wire of the novel cable anchoring system.

[0044] Preferably, the key parameters of the anchor cup include anchoring length, anchor cup diameter, anchor cup wall inclination angle, relative wall thickness of the front and rear ends of the anchor cup, average wall thickness of the anchor cup, friction coefficient between the casting and the anchor cup, anchor cavity structure, and chamfer of the inner wall of the anchor cup.

[0045] Preferably, in step A2, the combination of the key parameters of the anchor cup specifically involves:

[0046]

[0047] Preferably, step A3 specifically includes:

[0048] By analyzing the stress distribution and peak stress of anchor cups and castings with different anchorage lengths in the serviceability limit state and bearing capacity limit state, the influence law of anchorage length parameter is determined.

[0049] By analyzing the stress distribution and stress peak value of anchor cups and castings with different inner diameters of the loaded end in combined models M5-M8 under normal serviceability limit state and ultimate bearing capacity limit state, the influence law of the inner diameter parameter of the loaded end is determined.

[0050] By analyzing the stress distribution of anchor cups and castings with different anchor cup inclination angles in combined models M9-M13 under normal serviceability limit state and ultimate bearing capacity limit state, the influence law of anchor cup inclination angle parameter is determined.

[0051] By analyzing the stress distribution of anchor cups and castings with different relative wall thicknesses at the front and rear ends of the anchor cups in the serviceability limit state and the ultimate bearing capacity limit state, the influence law of the relative wall thickness parameter at the front and rear ends of the anchor cups is determined.

[0052] By analyzing the stress distribution of anchor cups and castings with different average wall thicknesses at the front and rear ends of the anchor cups in the serviceability limit state and the ultimate bearing capacity limit state, the influence law of the average wall thickness parameter at the front and rear ends of the anchor cups is determined.

[0053] By analyzing the stress distribution of anchor cups and castings with different friction coefficients between the anchor cup and the casting surface in combination models M22-M25 under normal serviceability limit state and ultimate bearing capacity limit state, the influence law of the friction coefficient parameter between the anchor cup and the casting surface is determined.

[0054] By analyzing the stress distribution of anchor cups and castings with different anchor cup and anchor cavity structures in combined models M26-M27 under normal service limit state and ultimate bearing capacity state, the influence law of anchor cup and anchor cavity structure parameters is determined.

[0055] By analyzing the stress distribution of the anchor cup and casting of the composite model M29 with chamfers under the serviceability limit state and the ultimate limit state, the influence law of chamfer parameters is determined.

[0056] Preferably, the influence law of the key parameters is as follows:

[0057] serial number parameter Influence Pattern degree of impact Optimization direction 1 Anchorage length Increasing the length can reduce anchor cup stress and improve the wire extrusion state. middle Maintain a reasonable economic length 2 Inner diameter of the loaded end Increasing the diameter can reduce the stress in the anchor cup and improve the extrusion state of the steel wire. middle Maintain a reasonable economic diameter 3 Anchor cup wall inclination angle Increasing the inclination angle has no significant effect on the stress on the anchor cup and the steel wire. weak Maintain a reasonable economic tilt 4 Relative wall thickness of front and rear ends of anchor cup Increasing the wall thickness at the loaded end can significantly reduce the stress in the anchor cup and improve the extrusion state of the steel wire. powerful Increase the wall thickness at the loaded end and decrease the wall thickness at the free end. 5 Anchor cup average wall thickness Increasing the average wall thickness can significantly reduce anchor cup stress and improve the wire extrusion state. powerful Increase wall thickness 6 Coefficient of friction between the anchor cup and the casting contact surface Increasing the coefficient of friction can significantly reduce anchor cup stress and improve the wire extrusion state. powerful Increase the coefficient of friction 7 Anchor cup and anchor cavity construction The use of a positive multi-stage conical structure can shift the peak stress of the anchor cup backward and reduce the peak, thus improving the extrusion state of the steel wire. powerful Adopting a positive multi-stage conical inner cavity 8 Chamfering of the inner wall of the anchor cup Setting a chamfer has no significant impact on the stress on the anchor cup and steel wire. weak No chamfering

[0058] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0059] This application describes a novel cable anchoring system where, along the direction from the front end hole to the rear end hole, the inner diameters of both the secondary frustum surface and the stepped transition surface increase. This results in the inner diameter of each secondary frustum surface near the front end hole being smaller than the inner diameter of the other end. When the casting moves relative to the anchor cup towards the front end hole or has a tendency to move relative to it, the casting abuts against the stepped transition surface and the secondary frustum surface. In addition to the axial bearing capacity provided by the secondary frustum surface, the stepped transition surface provides additional axial bearing capacity. Simultaneously, each level of the secondary frustum surface can provide both axial and radial bearing capacity. This novel cable anchoring system, through the combination of the stepped transition surface and the secondary frustum surface, effectively reduces the peak stress level between the anchor cup and the casting, making the stress distribution on the inner surface of the anchor cup more uniform and reasonable, and reducing the slip deformation of the casting, thereby improving the static and fatigue performance of the anchoring system. Attached Figure Description

[0060] Figure 1 This is a longitudinal cross-sectional schematic diagram of a novel cable anchoring system according to this application.

[0061] Figure 2 For the purposes of this application Figure 1 Enlarged view of part A (the axial section line of the secondary frustum surface is a straight line).

[0062] Figure 3 For the purposes of this application Figure 2 Enlarged view of section B in the middle.

[0063] Figure 3 a is the subject of this application. Figure 2 Enlarged view of section B (the axial section line of the step transition surface is a straight line).

[0064] Figure 3 b is the value of this application. Figure 2 Enlarged view of section B (the step transition surface has a concave part and a first convex part).

[0065] Figure 4 For the purposes of this application Figure 1 Enlarged view of part A in the middle.

[0066] Figure 4 a is the subject of this application. Figure 1 Enlarged view of section A (the cross-sectional line of the secondary frustum surface along the axial direction is a gentle curve).

[0067] Figure 4 b is the value of this application. Figure 1 Enlarged view of part A (the secondary frustum surface has pits and protrusions).

[0068] Figure 5This is a longitudinal cross-sectional schematic diagram of a novel cable anchoring system according to this application (with a steel wire guide sleeve).

[0069] Figure 6 For the purposes of this application Figure 5 Enlarged view of section C (with wire guide sleeve).

[0070] Figure 7 For the purposes of this application Figure 6 Enlarged view of section D in the middle.

[0071] Figure 7 a is the subject of this application. Figure 6 Enlarged view of section D (with wire guide sleeve, the axial section line of the stepped transition surface is a straight line).

[0072] Figure 7 b is the value of this application. Figure 6 Enlarged view of section D (with a wire guide sleeve, and a concave part and a first protrusion on the stepped transition surface).

[0073] Figure 8 This is a longitudinal cross-sectional schematic diagram of a novel cable anchoring system according to this application.

[0074] Figure 9 This is a schematic longitudinal section of the wire guide sleeve of this application.

[0075] Figure 9 a is a longitudinal cross-sectional schematic diagram of the wire guide sleeve of this application (the inner wall is similar to a hexagonal cone).

[0076] Figure 9 b is a left-side view of the wire guide sleeve of this application (the inner wall is similar to a hexagonal cone).

[0077] Figure 10 This is a schematic longitudinal section of the wire guide sleeve of this application.

[0078] Figure 10 a is a longitudinal cross-sectional view of the wire guide sleeve of this application (the inner wall is similar to a cone shape).

[0079] Figure 10 b is a left-side view of the wire guide sleeve of this application (the inner wall is similar to a cone shape).

[0080] Figure 11 This paper compares the stress amplitude of the anchor cup and the compressive stress amplitude of the casting before and after optimization in this application.

[0081] Figure 12 The stress curve and line graph of the anchor cup in this application along the length direction after optimization are shown.

[0082] Figure 13The stress curve and line graph of the anchor cup in this application along the thickness direction after optimization are shown.

[0083] Figure 14 The diagram shows the radial and circumferential stress trends of the casting and the relative slippage diagram between the anchor cup and the casting in this application.

[0084] Figure 15 This is a diagram showing the construction of the finite element analysis parameters for the anchor cup in this application.

[0085] Figure 16 This is a schematic diagram showing the parameters and stress distribution of the anchor cup reference model in this application.

[0086] Figure 17 The stress curves and line graphs of the anchor cup of this application along the length direction under different anchorage lengths are shown.

[0087] Figure 18 The stress curves and line graphs of the anchor cup of this application along the thickness direction under different anchorage lengths are shown.

[0088] Figure 19 The diagram shows the radial and circumferential stress trends of the casting and the relative slippage diagram between the anchor cup and the casting in this application.

[0089] Figure 20 The stress curves and line graphs of the anchor cup of this application along the length direction under different inner diameters of the loaded end are shown.

[0090] Figure 21 The stress curves and line graphs of the anchor cup of this application along the thickness direction under different inner diameters of the loaded end are shown.

[0091] Figure 22 The diagram shows the radial and circumferential stress trends of the casting and the relative slippage diagram between the anchor cup and the casting in this application.

[0092] Figure 23 The stress curves and line graphs of the anchor cup of this application along the length direction at different inclination angles are shown.

[0093] Figure 24 The stress curves and line graphs of the anchor cup of this application along the thickness direction at different inclination angles are shown.

[0094] Figure 25 The diagram shows the radial and circumferential stress trends of the casting and the relative slippage diagram between the anchor cup and the casting in this application.

[0095] Figure 26 The stress curves and line graphs of the anchor cup of this application along the length direction under different relative wall thicknesses at the front and rear ends are shown.

[0096] Figure 27 The stress curves and line graphs of the anchor cup of this application along the thickness direction under different relative wall thicknesses at the front and rear ends are shown.

[0097] Figure 28 The diagram shows the radial and circumferential stress trends of the casting and the relative slippage diagram between the anchor cup and the casting in this application.

[0098] Figure 29 The stress curves and line graphs of the anchor cup of this application along the length direction under different average wall thicknesses are shown.

[0099] Figure 30 The stress curves and line graphs of the anchor cup of this application along the thickness direction under different average wall thicknesses are shown.

[0100] Figure 31 The diagram shows the radial and circumferential stress trends of the casting and the relative slippage diagram between the anchor cup and the casting in this application.

[0101] Figure 32 The stress curves and line graphs of the anchor cup of this application along the length direction under different friction coefficients are shown.

[0102] Figure 33 The stress curves and line graphs of the anchor cup of this application along the thickness direction under different friction coefficients are shown.

[0103] Figure 34 The diagram shows the radial and circumferential stress trends of the casting and the relative slippage diagram between the anchor cup and the casting in this application.

[0104] Figure 35 The stress curves and line graphs of the anchor cup of this application along the length direction under different multi-level anchor cavity structures are shown.

[0105] Figure 36 The stress curves and polygonal diagrams of the anchor cup in this application along the thickness direction under different multi-level anchor cavity structures are shown.

[0106] Figure 37 This is a stress cloud diagram of the anchor cup-cast body with reverse multi-stage structure of the anchor cavity in this application.

[0107] Figure 38 The diagram shows the radial and circumferential stress trends of the casting and the relative slippage diagram between the anchor cup and the casting in this application.

[0108] Figure 39 The stress curves and line graphs of the anchor cup of this application along the length direction under different chamfers on the inner wall of the anchor cup are shown.

[0109] Figure 40 The stress curves and line graphs of the anchor cup in this application along the thickness direction under different chamfers on the inner wall of the anchor cup are shown.

[0110] Figure 41 The diagram shows the radial and circumferential stress trends of the casting and the relative slippage diagram between the anchor cup and the casting in this application.

[0111] Figure 42 This is a schematic diagram of the fit between the wire strand and the wire guide sleeve in this application.

[0112] Figure 43 Stress cloud diagram of anchor cup-cast body with positive multi-level structure of anchor cavity. Detailed Implementation

[0113] The present invention will be further described in detail below with reference to experimental examples and specific embodiments. However, this should not be construed as limiting the scope of the above-mentioned subject matter of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0114] Unless otherwise specified, the use of terms such as "upper," "lower," "left," "right," "center," "inner," and "outer" to indicate orientation or positional relationships in the description of specific embodiments of the present invention is based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationship in which the product / equipment / device is typically placed during use. These terms are merely for the purpose of facilitating the description of the present invention or simplifying the description in specific embodiments, enabling those skilled in the art to quickly understand the solution, and do not indicate or imply that a particular device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, they should not be construed as limitations on the present invention.

[0115] Furthermore, the use of terms such as "horizontal," "vertical," "suspended," and "parallel" does not imply that the corresponding device / component / element must be absolutely horizontal, vertical, suspended, or parallel, but rather that it can be slightly tilted or have a deviation. For example, "horizontal" merely means that its direction is more horizontal relative to "vertical," not that the structure must be completely horizontal, but that it can be slightly tilted. Alternatively, it can be simplified to mean that the corresponding device / component / element, when set in a "horizontal," "vertical," "suspended," or "parallel" direction, can have an error / deviation of ±10% relative to the corresponding direction, more preferably within ±8%, more preferably within ±6%, more preferably within ±5%, and more preferably within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its function in the present invention.

[0116] Furthermore, the use of terms such as "first," "second," "third," etc. in terminology is merely for distinguishing identical or similar components and should not be interpreted as emphasizing or implying the relative importance of a particular component.

[0117] Furthermore, in the description of the embodiments of the present invention, "several", "more than", and "a number of" represent at least two. The number can be any number, such as 2, 3, 4, 5, 6, 7, 8, or 9, and can even exceed nine.

[0118] Furthermore, in the description of the technical solution of this invention, unless otherwise explicitly specified / limited / restricted, the terms "set up," "install," "connect," "link," "provided with," "laid out," and "arranged" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to common connection methods in the art, such as welding, riveting, bolting, and threaded connections. Such connections can be mechanical, electrical, or communication connections; they can be direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components.

[0119] Example 1

[0120] like Figure 1-10 As shown in the figure, a novel cable anchoring system according to this embodiment includes an anchor cup 1, wherein: a through main anchor cavity 6 is provided on the anchor cup 1, such that one end of the main anchor cavity 6 has a front end hole 7 and the other end has a rear end hole 8; at least two secondary frustum surfaces 10 are sequentially provided on the inner wall of the main anchor cavity 6 along the through direction of the main anchor cavity 6, so that the main anchor cavity 6 forms at least two frustum anchor cavities 11, and a stepped transition surface 15 is provided between adjacent secondary frustum surfaces 10; along the direction from the front end hole 7 to the rear end hole 8, the inner diameter of the secondary frustum surface 10 and the inner diameter of the stepped transition surface 15 both increase.

[0121] The novel cable anchoring system described in this application increases the inner diameter of both the secondary frustum surface 10 and the stepped transition surface 15 along the direction from the front end hole 7 to the rear end hole 8. This results in the inner diameter of each secondary frustum surface 10 near the front end hole 7 being smaller than the inner diameter of the other end. When the casting 2 moves relative to the anchor cup 1 towards the front end hole 7 or has a tendency to move relative to it, the casting 2 abuts against the stepped transition surface 15 and the secondary frustum surface 10, providing a foundation for axial bearing on the secondary frustum surface 10. The stepped transition surface 15 provides additional axial bearing capacity, while the secondary frustum surfaces 10 of each stage provide both axial and radial bearing capacity. The novel cable anchoring system described in this application, through the step transition surface 15 and the secondary frustum surfaces 10, the multi-stage frustum anchor cavity 11 structure can effectively reduce the peak stress level of the anchor cup 1 and the casting 2, making the stress distribution on the inner surface of the anchor cup 1 more uniform and reasonable, and reducing the slip deformation of the casting 2, thereby improving the static and fatigue performance of the anchoring system.

[0122] Along the direction from the front end hole 7 to the rear end hole 8, the inner diameter of the secondary frustum surface 10 increases such that the cross-sectional diameter of the secondary frustum surface 10 near the front end hole 7 is smaller than the cross-sectional diameter of the secondary frustum surface 10 near the rear end hole 8.

[0123] Along the direction from the front end hole 7 to the rear end hole 8, the inner diameter of the stepped transition surface 15 is increased such that the cross-sectional diameter of the stepped transition surface 15 near the front end hole 7 is smaller than the cross-sectional diameter of the stepped transition surface 15 near the rear end hole 8.

[0124] Preferably, at least two adjacent secondary frustum surfaces 10 are parallel to facilitate the manufacture of the anchor cup 1; a recessed portion 16 is provided on the stepped transition surface 15; a first protrusion 17 is provided on the stepped transition surface 15; the bottom of the recessed portion 16 is inclined toward the front end hole 7; pits 12 are provided on the secondary frustum surface 10; and protrusions 13 are provided on the secondary frustum surface 10.

[0125] The wall thickness of the anchor cup 1 at the loaded end is greater than the wall thickness of the anchor cup 1 at the free end.

[0126] The anchor cup 1 can be used for main cables, suspenders, or stay cables.

[0127] The novel cable anchoring system described in this application involves splitting the ends of the steel wire strands 14 after passing them through the front end hole 7, forming multiple steel wires 3. The main anchor cavity 6 of the anchor cup 1 is filled with a casting 2 to fix the separated steel wires 3 at the ends of the steel wire strands 14. The diameter of the rear end hole 8 is larger than the diameter of the front end hole 7. The inner diameter of the secondary frustum surface 10 gradually increases along the direction from the front end hole 7 to the rear end hole 8. A stepped transition surface 15 is provided between adjacent secondary frustum surfaces 10. The inner side of the stepped transition surface 15 is inclined towards the front end hole 7. The inner diameter of the secondary frustum surface 10 on the side of the stepped transition surface 15 closest to the front end hole 7 is smaller than the inner diameter of the secondary frustum surface 10 on the side of the stepped transition surface 15 furthest from the front end hole 7. Therefore, the diameter of each secondary frustum surface 10 near the front end hole 7 is smaller than the diameter of the other end, and the diameter values ​​are all between the diameter of the front end hole 7 and the diameter of the rear end hole 8. When the steel wire strand 14 is under tension, the steel wire 3 can drive the casting 2 to move relative to the anchor cup 1 towards the front end hole 7 or has a tendency to move relative to it. At this time, the casting 2 can abut against the stepped transition surface 15, and provide additional axial bearing force through the stepped transition surface 15 between several secondary frustums. At the same time, since the inner diameter of the secondary frustum surface 10 on the side of the stepped transition surface 15 close to the front end hole 7 is smaller than the inner diameter of the secondary frustum surface 10 on the side of the stepped transition surface 15 away from the front end hole 7, the secondary frustum surfaces 10 at each level can provide the combined effect of axial bearing and radial bearing. The novel cable anchoring system described in this application, through the step transition surface 15 and the secondary frustum surface 10, the multi-stage frustum anchor cavity 11 structure can effectively reduce the peak stress level of the anchor cup 1 and the casting 2, make the stress distribution on the inner surface of the anchor cup 1 more uniform and reasonable, and reduce the slip deformation of the casting 2, thereby improving the static performance and fatigue performance of the anchoring system.

[0128] Example 2

[0129] The novel cable anchoring system described in this embodiment differs from that in Embodiment 1 in that it further includes a steel wire strand 14. The main anchor cavity 6 is filled with a casting 2, which is in contact with both the secondary frustum surface 10 and the step transition surface 15. The steel wire strand 14 passes through the front end hole 7, and at least a portion of the steel wire strand 14 is located within the casting 2.

[0130] This application also discloses a novel cable anchoring system. During installation and use, the ends of the steel wire strands 14 are passed through the front end hole 7 and then split to form multiple steel wires 3. The main anchor cavity 6 of the anchor cup 1 is filled with a casting 2 to fix the separated steel wires 3 at the ends of the steel wire strands 14. The diameter of the rear end hole 8 is larger than the diameter of the front end hole 7. The inner diameter of the secondary frustum surface 10 gradually increases along the direction from the front end hole 7 to the rear end hole 8. A stepped transition surface 15 is provided between adjacent secondary frustum surfaces 10. The inner side of the stepped transition surface 15 is inclined towards the front end hole 7. The inner diameter of the secondary frustum surface 10 on the side of the stepped transition surface 15 closer to the front end hole 7 is smaller than the inner diameter of the secondary frustum surface 10 on the side of the stepped transition surface 15 away from the front end hole 7. It can be concluded that the diameter of each secondary frustum surface 10 at the end closer to the front end hole 7 is smaller than the diameter at the other end, and the diameter value is between the diameter of the front end hole 7 and the diameter of the rear end hole 8. When the steel wire strand 14 is under tension, the steel wire 3 can drive the casting 2 to move relative to the anchor cup 1 towards the front end hole 7 or has a tendency to move relative to it. At this time, the casting 2 can abut against the stepped transition surface 15, and provide additional axial bearing force through the stepped transition surface 15 between several secondary frustums. At the same time, since the inner diameter of the secondary frustum surface 10 on the side of the stepped transition surface 15 close to the front end hole 7 is smaller than the inner diameter of the secondary frustum surface 10 on the side of the stepped transition surface 15 away from the front end hole 7, the secondary frustum surfaces 10 at each level can provide the combined effect of axial bearing and radial bearing. The novel cable anchoring system described in this application, through the step transition surface 15 and the secondary frustum surface 10, the multi-stage frustum anchor cavity 11 structure can effectively reduce the peak stress level of the anchor cup 1 and the casting 2, make the stress distribution on the inner surface of the anchor cup 1 more uniform and reasonable, and reduce the slip deformation of the casting 2, thereby improving the static performance and fatigue performance of the anchoring system.

[0131] In a preferred embodiment, a wire guide sleeve 20 is further provided inside the main anchor cavity 6. The wire strand 14 passes through the wire guide sleeve 20 and is arranged in a split configuration. The inner wall 19 of the wire guide sleeve 20 has a continuously changing curvature along the opening direction of the wire guide sleeve 20. The portion of the inner wall 19 of the wire guide sleeve 20 near the front end hole 7 is smoothly tangential to the corresponding portion of the wire strand 14. The portion of the inner wall 19 of the wire guide sleeve 20 near the rear end hole 8 is smoothly tangential to the outermost layer of the wire 3 corresponding to the portion of the wire strand 14.

[0132] More specifically, a wire guide sleeve 20 is also provided inside the main anchor cavity 6. The wire strand 14 passes through the wire guide sleeve 20, and the portion of the wire strand 14 located between the wire guide sleeve 20 and the rear end hole 8 is split into at least 3 wires 3. The inner wall 19 of the wire guide sleeve 20 has a continuously changing curvature along the opening direction of the wire guide sleeve 20. The portion of the inner wall 19 of the wire guide sleeve 20 near the front end hole 7 is smoothly tangential to the outer wall of the corresponding portion of the wire strand 14. The portion of the inner wall 19 of the wire guide sleeve 20 near the rear end hole 8 is smoothly tangential to the outermost layer of wires 3 after the wire strand 14 is split.

[0133] like Figure 42 As shown, in conventional anchoring systems, the steel wires are tightly packed when entering the small end of the anchor cup. However, at the large end of the anchor cup, due to the wire separating plate, the starting and ending points of each steel wire are determined, resulting in a zigzag pattern of the steel wires within the anchor cup. The steel wires also exhibit angles at the small end, making this area prone to fatigue fracture under cyclic loading. In this application, the steel wire guide sleeve 20 is used to ensure that the outermost steel wire 3 in the steel wire strand 14 transitions along the curve of the inner wall of the steel wire guide sleeve 20 when it spreads out, while the inner steel wires 3 of the steel wire strand 14 transition along the curve of the adjacent outer steel wire 3 when they spread out. This effectively avoids at least most of the angles of the steel wires 3, significantly improving the fatigue resistance of the steel wires 3 in this area.

[0134] In a preferred embodiment, the wire guide sleeve 20 is arranged in a trumpet shape.

[0135] In a preferred embodiment, the inner wall 19 of the wire guide sleeve 20 is polygonal in the cross-sectional direction of the wire guide sleeve 20.

[0136] In a preferred embodiment, along the opening direction of the wire guide sleeve 20, the cross-sectional line of the inner surface of the wire guide sleeve 20 is a straight line, a circular curve, an elliptical curve, a power function curve, an exponential function curve, a hyperbola, or a spiral.

[0137] Alternatively, in another preferred embodiment, along the opening direction of the wire guide sleeve 20, the shape of the cross-sectional line on the inner surface of the wire guide sleeve 20 is a combination of a straight line and a circular curve, an elliptical curve, a power function curve, an exponential function curve, a hyperbola, or a spiral.

[0138] The novel cable anchoring system described in this application can be specifically used as a hot-cast anchor cup 1 suitable for parallel steel wire 3 cables.

[0139] In view of the problems existing in the novel cable anchoring system mentioned in the background art, this embodiment proposes a novel anchor cavity structure to improve the stress performance of the anchor cup 1 structure and enhance the static bearing capacity and fatigue bearing capacity of the anchor cup 1 for anchoring the casting 2 and the steel wire 3.

[0140] Anchor cup 1 structure: The anchor cup 1 structure preferably consists of anchor cup 1, casting body 2, parallel steel wire strands 14, steel wire guide sleeve 20, and rear end wire splitting plate 5.

[0141] Multi-stage frustum anchor cavity 11: A frustum-shaped main anchor cavity 6, extending from front to back, is provided in the middle of the anchor cup 1 structure. The front end hole 7 of the anchor cup 1 is smaller, and the rear end hole 8 is larger. The surface 9 of the main anchor cavity has a single conical angle. Multiple secondary frustum surfaces 10, connected by stepped transition surfaces 15, are further provided on the surface 9 of the main anchor cavity, thereby changing the surface shape of the main anchor cavity 6 and forming a multi-stage frustum anchor cavity 11. All secondary frustum surfaces 10 have the same conical angle and length. The front end diameter of each secondary frustum surface 10 is smaller than the rear end diameter, and the diameter value is between the diameter of the front end hole 7 and the diameter of the rear end hole 8. The connection between the stepped transition surface 15 and the adjacent secondary frustum surface 10 is rounded with a chamfer to avoid local stress concentration.

[0142] This application describes a novel cable anchoring system where the cone angle of the secondary frustum surface 10 is smaller than that of the original main anchor cavity surface 9, exhibiting an outward convex shape. Additional axial bearing capacity is primarily provided through the stepped transition surfaces 15 between the secondary frustums. This differs from the constraint mechanism of the concave structure in the prior art, where the concave structure has limited practical effectiveness. The multi-stage frustum anchor cavity 11 effectively reduces the peak stress levels of the anchor cup 1 and the casting 2, resulting in a more uniform and reasonable stress distribution on the inner surface of the anchor cup 1 and reducing the slippage deformation of the casting 2, thereby improving the static and fatigue performance of the anchoring system.

[0143] Continuous curved frustum anchor cavity 11: The cross-sectional line of each secondary frustum surface 10 along the axial direction can take various forms, including but not limited to straight lines, circular curves, elliptic curves, power function curves, exponential function curves, hyperbolas, and spirals. The specific curve form selection and arrangement can be determined according to the actual stress control requirements of the anchor cup 1. Compared with the conventional single conical anchor cavity structure, the continuous stepped transition surface 15 combined with the curved frustum anchor cavity 11 can alleviate the local stress concentration phenomenon at the front end of the anchor cup 1, adjust the stress distribution on the anchor cup 1, casting 2, and interface within the entire anchoring length of the anchor cup 1, and achieve low-peak and smooth stress distribution on the anchor cup 1, thereby improving the static and fatigue performance of the anchoring system.

[0144] Rough Surface: Based on the multi-stage frustum anchor cavity 11, the overall roughness of the interface between the anchor cup 1 and the casting 2 can be further improved through machining methods to form a rough surface. Sharp points or abrupt changes in shape should be avoided on the rough surface; rounded chamfers should be used in these areas to prevent local stress concentration. Simultaneously, the geometric features of the rough surface should not be too prominent to avoid interfering with the spatial arrangement of the steel wire 3 within the anchor cavity. Various methods and forms can be used to improve the surface roughness of the anchor cavity. Preferred methods for better machining control include, but are not limited to, setting several regular or irregular local pits 12 or protrusions 13 on the main anchor cavity surface 9 to increase the contact area between the anchor cup 1 and the casting 2 and improve mechanical engagement; or increasing the roughness of the main anchor cavity surface 9 through machining processes to improve the friction coefficient of the interface between the anchor cup 1 and the casting 2. Compared with a conventional flat surface, a rough surface can effectively improve the anchoring force of the anchor cup 1 on the casting 2, reduce the slippage deformation of the casting 2, and further improve the anchoring efficiency of the anchor cup 1.

[0145] Novel Cable Anchoring System Type: This novel cable anchoring system is applicable to main cable anchor cup 1, stay cable anchor cup 1, or suspension cable anchor cup 1. The main cable anchor cup 1 can be further divided into tie rod anchoring type and bearing anchoring type. For different types of novel cable anchoring systems, only conventional design and structural adjustments to the external shape of the anchor cup 1 are needed based on the anchoring method and stress characteristics of each system; the internal anchor cavity structure remains unaffected.

[0146] Parallel wire strand 14: The parallel wire strand 14 is composed of no fewer than 7 high-strength steel wires 3 arranged in a hexagonal or hexagonal shape with missing corners, and the strength of the steel wires 3 is not limited. The parallel wire strand 14 extends into the anchor cup 1 from the front hole 7, passes through the wire guide sleeve 20, and then spreads out evenly in the conical anchor cavity, with the distance between adjacent steel wires 3 in the same cross section being equal. Near the rear hole 8 of the anchor cup 1, the end of the steel wire 3 passes through the rear wire separating plate 5 for positioning and is then treated with a head-up process. The steel wire 3 is anchored in the main anchor cavity 6 by the casting 2.

[0147] Wire guide sleeve 20: A wire guide sleeve 20 is installed near the front end hole 7 of the anchor cavity. After the parallel wire strands 14 are inserted into the anchor cup 1, they first pass through the wire guide sleeve 20 and spread out evenly. The wire guide sleeve 20 is shaped like a wire guide sleeve and tightly wraps around the wire strands 14. Its sleeve wall can be of uniform thickness. The cross-sectional line of the inner wall 19 of the wire guide sleeve 20 along the axial direction of the wire guide sleeve 20 is a gentle curve, specifically a spiral curve, with the curvature at both ends being 0 and the curvature in the middle being a constant value, so that its curvature changes continuously. The wire guide sleeve 20 ensures that the wire strands 14 maintain a smooth linear shape during the spreading process and does not have obvious bending, thereby reducing the local stress of the wire 3 and improving the fatigue resistance. Its specific material can be the same alloy material, cold casting material, mild steel, etc. as the casting body 2. The wire guide sleeve 20 is fixed in the anchor cavity by the casting body 2.

[0148] Casting 2: Casting 2 can be made of multi-element alloy materials, including but not limited to zinc-copper alloys and zinc-aluminum-copper alloys, and is formed into a conical shape with the steel wire 3 in the anchor cavity by hot casting. This anchor cavity structure is also applicable to the cold-cast anchor cup 1. For the cold-cast anchor cup 1, only the material of casting 2 in the anchor cup 1 needs to be changed to commonly used cold-cast filler, and the design and casting should be carried out according to the corresponding material characteristics. The internal anchor cavity structure remains unaffected.

[0149] Example 3

[0150] This embodiment describes a design method for the novel cable anchoring system described in Embodiment 1, comprising the following steps: S1. Determining the position of the main anchor cavity surface 9 based on the diameter of the front end hole 7 and the diameter of the rear end hole 8; S2. Determining the length of each secondary frustum surface 10; S3. Determining the end position of the secondary frustum surface 10 near the front end hole 7 based on the length of the secondary frustum surface 10 and the position of the main anchor cavity surface 9; S4. Determining the angle of the secondary frustum surface 10 relative to the main anchor cavity surface 9; S5. Determining the angle of the stepped transition surface 15 relative to the secondary frustum surface 10 based on the angle of the secondary frustum surface 10 relative to the main anchor cavity surface 9.

[0151] Example 4

[0152] like Figure 1-43As shown in this embodiment, a design method for the novel cable anchoring system described in Embodiment 1 is mainly aimed at stress minimization and structural applicability, durability, and economy. Through iterative design under a multi-parameter system, the finite element calculation results of key parameters, including anchoring length, anchor cup 1 diameter, anchor cup 1 inclination angle, relative wall thickness of anchor cup 1 front and rear ends, average wall thickness of anchor cup 1, friction coefficient between casting 2 and anchor cup 1, anchor cavity structure, and chamfer of the inner wall of anchor cup 1, are analyzed and studied in depth. Specifically, the method includes the following steps: analyzing the influence of the stress distribution results of the cable anchoring system benchmark model on the performance of anchor cup 1 and casting 2; based on this, combining the key parameters of anchor cup 1, resulting in 29 combination models M1-M29, as shown in Table 1; further analysis comprehensively examining the stress distribution of each parameter on anchor cup 1, casting 2, and steel wire 3 and its influence on fatigue performance, and finally proposing a strength-matched, high-fatigue-resistance anchor cup 1 structural design scheme.

[0153] The average wall thickness of anchor cup 1 is t = (loaded end wall thickness + free end wall thickness) / 2.

[0154] like Figure 15 As shown, the reference model of the cable anchoring system has the following characteristics: the anchoring length L is 510 mm, the load-bearing end radius r is 40.5 mm, the inclination angle α of the anchor cup 1 is 7.125°, the average wall thickness t of the anchor cup 1 is 50 mm, the friction coefficient of the contact surface between the anchor cup 1 and the casting 2 is 0.2, and the inner wall of the anchor cavity is smooth without chamfering. All the above dimensional parameters meet the design values ​​of the anchor cup 1 parameters. A stress study of the anchor cup 1 in the reference model of the cable anchoring system shows that the Mises stress is related to the yield of the anchor cup 1, with the maximum stress located at the contact point between the small end and the end of the casting 2, gradually decreasing along the length and thickness of the anchor cup 1. The principal tensile stress of the anchor cup 1 is related to its fatigue performance; the location of the maximum principal tensile stress differs from the location of the maximum Mises stress, tending towards the large end, and gradually decreasing along the length and thickness of the anchor cup 1.

[0155] Table 1. Parameter Settings for Cable Anchoring System Modeling

[0156]

[0157] The legends in each chart are explained as follows: NLT: Maximum principal tensile stress in the length direction of anchor cup 1 under normal serviceability limit state; ULT: Maximum principal tensile stress in the length direction of anchor cup 1 under ultimate bearing capacity limit state; NL-Mises: Maximum Mises stress in the length direction of anchor cup 1 under normal serviceability limit state; UL-Mises: Maximum Mises stress in the length direction of anchor cup 1 under ultimate bearing capacity limit state; NDT: Maximum principal tensile stress in the thickness direction of anchor cup 1 under normal serviceability limit state; UDT: Maximum principal tensile stress in the thickness direction of anchor cup 1 under ultimate bearing capacity limit state; ND-Mises: Maximum Mises stress in the thickness direction of anchor cup 1 under normal serviceability limit state; UD-Mises: Maximum Mises stress in the thickness direction of anchor cup 1 under ultimate bearing capacity limit state; NJ: Radial compressive stress of casting 2 under normal serviceability limit state; UJ: Radial compressive stress of casting 2 under ultimate bearing capacity limit state; NQ: Circumferential compressive stress of casting 2 under normal serviceability limit state; UQ: Circumferential compressive stress of casting 2 under ultimate bearing capacity limit state.

[0158] Fatigue resistance performance analysis of various parameters of anchor cup 1.

[0159] Anchorage length L: Anchorage length refers to the effective length of the cable inside the anchor cup 1 used for anchoring. It directly affects the stress distribution and transmission method between the cable and the anchorage system. A longer anchorage length can provide a larger anchorage area, increasing the contact area between the cable and the anchorage system, which helps to disperse and reduce the stress on the anchor cup 1, reduce the degree of local stress concentration, and thus improve the fatigue resistance of the anchorage system. However, an excessively long anchorage length will increase material and construction costs and may cause the anchor cup 1 to swing or vibrate, affecting the stability and reliability of the anchorage system. By analyzing the stress distribution and peak stress of the anchor cup 1 and the casting 2 with different anchorage lengths in the combined models M1-M4 under the serviceability limit state and the ultimate limit state, the influence law of the anchorage length parameter is determined.

[0160] like Figure 17 and 18 As shown in the figure, the analysis of the two sets of results indicates that the maximum principal tensile stress of anchor cup 1 is located at the contact point between the small end and the end of casting 2, and gradually decreases along the length and thickness of anchor cup 1. The maximum Mises stress also gradually decreases along the length and thickness of anchor cup 1. Under different anchoring lengths, the maximum principal tensile stress and maximum Mises stress of anchor cup 1 do not change significantly.

[0161] like Figure 19As shown, analysis of the radial and circumferential stress line graphs of casting 2 reveals that, under the normal serviceability limit state, the radial compressive stress of casting 2 is generally greater than the circumferential compressive stress. Under the ultimate limit state, the circumferential compressive stress of casting 2 is greater than the radial compressive stress, and anchor cup 1 is in a high-stress state. The relative slip line graph of anchor cup 1 and casting 2 shows that when the anchoring length is 610 mm, the relative slip between anchor cup 1 and casting 2 is minimal, but the overall change is not significant.

[0162] In summary, although the stress distribution and magnitude of anchor cup 1 vary slightly with different anchoring lengths, there is no significant improvement in the stress distribution of anchor cup 1. This may indicate that when considering anchoring length, other factors need to be taken into account, and the design needs to be further optimized to improve the performance of anchor cup 1.

[0163] Load-bearing end inner diameter: The load-bearing end inner diameter refers to the diameter of the internal space of the anchor cup 1, which directly affects the contact area and force transmission effect between the cable and the anchor cup 1. A larger inner diameter can provide a wider anchoring area, which is conducive to the uniform distribution of force between the cable and the anchor cup 1, reduces the possibility of local stress concentration, and thus improves the fatigue resistance of the anchoring system. However, a larger inner diameter increases the hollow part of the anchor cup 1, leading to a decrease in material utilization. Furthermore, as the inner diameter increases, the overall size of the anchor cup 1 also increases, resulting in increased weight and increased difficulty in installation and maintenance. By analyzing the stress distribution and stress peak of anchor cup 1 and casting 2 with different load-bearing end inner diameters (combined models M5-M8) under the serviceability limit state and ultimate limit state, the influence law of the load-bearing end inner diameter parameter is determined.

[0164] like Figure 20 and 21 As shown, the analysis of the two sets of results indicates that the maximum principal tensile stress of anchor cup 1 is located at the contact point between the small end and the end of casting 2, and gradually decreases along the length and thickness of anchor cup 1. The maximum principal tensile stress of anchor cup 1 does not change significantly under different inner diameters of the loaded end. The maximum Mises stress gradually decreases along the length and thickness of anchor cup 1. As the inner diameter of the loaded end gradually increases, the maximum Mises stress of anchor cup 1 gradually decreases.

[0165] like Figure 22 As shown, analysis of the radial and circumferential stress line graphs of casting 2 reveals that, under the normal serviceability limit state, the radial compressive stress of casting 2 is generally greater than the circumferential compressive stress. The radial compressive stress of casting 2 varies significantly with the increase of the radius of the loaded end, generally showing a decreasing trend. Under the ultimate limit state, both the circumferential and radial compressive stresses of casting 2 decrease with the increase of the radius of the loaded end. The relative slip line graph of anchor cup 1 and casting 2 shows that the relative slip between anchor cup 1 and casting 2 remains essentially unchanged overall.

[0166] In the above analysis, although a larger inner diameter at the loaded end has no significant effect on the maximum principal tensile stress and maximum Mises stress of anchor cup 1, it does have a certain mitigating effect on the radial and circumferential compressive stresses of casting 2. Specifically, a larger inner diameter at the loaded end can bring the following advantages and improvements:

[0167] 1. Reducing the radial compressive stress of casting 2: A larger inner diameter at the loaded end helps to reduce the stress concentration inside anchor cup 1, thus dispersing and reducing the radial compressive stress inside anchor cup 1. This helps to reduce the stress concentration of casting 2 and improve its fatigue resistance.

[0168] 2. Improve the circumferential compressive stress distribution of casting 2: A larger inner diameter at the loaded end may result in a more uniform stress distribution on anchor cup 1, thereby reducing the circumferential compressive stress of casting 2. This can reduce the stress level of casting 2 under ultimate bearing capacity conditions, which helps to improve the durability and stability of anchor cup 1.

[0169] 3. Reduce stress concentration: A larger inner diameter of the loaded end can provide a wider anchorage area, which is conducive to the uniform distribution of force between the cable and the anchor cup 1, thereby reducing the possibility of local stress concentration and helping to improve the overall fatigue resistance of the anchorage system.

[0170] In summary, a larger inner diameter at the load-bearing end has certain advantages in the design of anchor cup 1, which can improve the stress distribution of the casting 2, reduce the stress concentration, and improve the fatigue resistance of anchor cup 1.

[0171] Anchor Cup 1 Inward Inclination Angle: The inward inclination angle of anchor cup 1 refers to the angle between the interior of anchor cup 1 and its axis. In other words, when anchor cup 1 is placed horizontally, the inward inclination angle is the angle between the interior of anchor cup 1 and the horizontal plane. It directly affects the force transmission effect and anchoring performance between the casting 2 and anchor cup 1. Generally, the larger the inward inclination angle of anchor cup 1, the more uniform the force distribution between anchor cup 1 and casting 2. A larger inward inclination angle can provide a wider anchoring area, which is beneficial for the uniform distribution of force between casting 2 and anchor cup 1. This reduces the possibility of local stress concentration, thereby improving the fatigue resistance of the anchoring system. However, a larger inward inclination angle can make the structure of anchor cup 1 more unstable, easily affected by external forces, and prone to tilting or displacement. It may also reduce the contact area between anchor cup 1 and the cable, affecting the force transmission effect and thus reducing the anchoring effect. By analyzing the stress distribution of anchor cup 1 and casting 2 with different inclination angles of anchor cup 1 wall in combination models M9-M13 under normal serviceability limit state and ultimate bearing capacity limit state, the influence law of the inclination angle parameter of anchor cup 1 wall is determined.

[0172] like Figure 23 and Figure 24As shown, the analysis of the above two sets of results indicates that the maximum principal tensile stress of anchor cup 1 is located at the contact point between the small end and the end of casting 2, and gradually decreases along the length and thickness of anchor cup 1. In the broken line diagrams of the maximum principal tensile stress and the maximum Mises stress of anchor cup 1, along the length or thickness of anchor cup 1, the maximum principal tensile stress and the maximum Mises stress remain essentially unchanged with the change of the inclination angle.

[0173] like Figure 25 As shown, analysis of the radial and circumferential stress line graphs of casting 2 reveals that, under normal serviceability limits, the circumferential compressive stress of casting 2 remains essentially unchanged with the change in inclination angle, while the radial compressive stress of casting 2 initially increases, then decreases, and then increases again with the increase of the inclination angle. This indicates that under normal serviceability limits, the radial compressive stress of casting 2 reaches its minimum when the inclination angle is between 7.5° and 8°. At this point, the pressure on the steel wire 3 inside casting 2 is relatively small, which can improve the stress of anchor cup 1 to some extent. Under the ultimate limit state, the circumferential and radial compressive stresses of casting 2 remain essentially unchanged. Analysis of the relative slip line graphs of anchor cup 1 and casting 2 shows that the relative slip between anchor cup 1 and casting 2 gradually decreases with the increase of the inclination angle. A larger inclination angle can reduce the relative slip between casting 2 and anchor cup 1 to some extent.

[0174] Based on the above analysis, the influence of the inclination angle on the stress and relative slippage of anchor cup 1 is derived:

[0175] 1. Principal Tensile Stress Analysis: The maximum principal tensile stress appears at the contact point between the small end of anchor cup 1 and the end of casting 2, and gradually decreases along the length and thickness of anchor cup 1. However, the changes in principal tensile stress and Mises stress are not significant under different inclination angles, indicating that the inclination angle has a limited impact on the principal tensile stress of anchor cup 1.

[0176] 2. Radial and Circumferential Stress Analysis: Under normal serviceability limits, the circumferential compressive stress of casting 2 is basically unaffected by the inclination angle, while the radial compressive stress shows a trend of first increasing, then decreasing, and then increasing again as the inclination angle increases. This indicates that, within a certain range, a larger inclination angle helps to reduce the radial compressive stress of casting 2.

[0177] 3. Relative slip analysis: As the inclination angle increases, the relative slip between anchor cup 1 and casting 2 gradually decreases. This means that a larger inclination angle can reduce the relative movement between casting 2 and anchor cup 1 to a certain extent, thereby improving the stability of anchor cup 1.

[0178] In summary, the inclination angle has a limited effect on improving the stress distribution of the anchor cup 1. However, a larger inclination angle can reduce the relative slippage between the casting 2 and the anchor cup 1 to some extent, which helps to improve the stability and durability of the anchor cup 1.

[0179] Relative wall thickness of front and rear ends of anchor cup 1

[0180] The relative wall thickness of anchor cup 1 refers to the wall thickness of the free end (unloaded end) and the loaded end of anchor cup 1. The relative wall thickness affects the internal stress distribution and stress concentration of anchor cup 1. Variations in the relative wall thickness affect the internal stress distribution and fatigue performance of anchor cup 1. By analyzing the stress distribution of anchor cup 1 and casting 2 with different relative wall thicknesses at the front and rear ends of combined models M14-M17 under the serviceability limit state and ultimate limit state, the influence of the relative wall thickness parameter at the front and rear ends of anchor cup 1 is determined.

[0181] like Figure 26 and 27 As shown, the analysis of the above two sets of results indicates that the maximum principal tensile stress of anchor cup 1 is located at the contact point between the small end and the end of casting 2, and gradually decreases along the length and thickness of anchor cup 1. In the broken line diagrams of the maximum principal tensile stress and maximum Mises stress of anchor cup 1, along the length or thickness of anchor cup 1, both the maximum principal tensile stress and the maximum Mises stress show a decreasing trend with increasing relative wall thickness (load-bearing end wall thickness), demonstrating a significant effect on improving the stress of anchor cup 1.

[0182] like Figure 28 As shown in the figure above, analysis of the radial and circumferential stress line diagrams of casting 2 reveals that, under the serviceability limit state, the circumferential and radial compressive stresses of casting 2 remain essentially unchanged with the increase of the relative wall thickness at the front and rear ends. Under the ultimate limit state, the circumferential and radial compressive stresses of casting 2 decrease with the increase of the relative wall thickness (load-bearing end), but the overall change is not significant. Analysis of the relative slip line diagrams of anchor cup 1 and casting 2 shows that the relative slip between anchor cup 1 and casting 2 gradually decreases with the increase of the relative wall thickness (load-bearing end).

[0183] In summary, the relative wall thickness significantly improves the stress of anchor cup 1. Increasing the wall thickness at the load-bearing end effectively reduces stress, which not only improves fatigue performance but also reduces the radial pressure on the steel wire 3, thereby improving the overall performance of anchor cup 1.

[0184] Average wall thickness of anchor cup 1: The average wall thickness of anchor cup 1 at both ends refers to the average value of the wall thickness at both ends of anchor cup 1. Generally, a larger wall thickness can reduce the stress level under load and increase its service life. The figure below shows the stress and displacement analysis of anchor cup 1 under different average wall thickness parameters. By analyzing the stress distribution of anchor cup 1 and casting 2 in combined models M18-M21 with different average wall thicknesses at both ends of anchor cup 1 under the serviceability limit state and the ultimate limit state, the influence of the average wall thickness parameter at both ends of anchor cup 1 is determined.

[0185] like Figure 29 and 30As shown in the figure, the analysis of the above two sets of results indicates that as the average wall thickness of the front and rear ends of anchor cup 1 increases, both the principal tensile stress and Mises stress on anchor cup 1 decrease significantly. Figure 36 Analysis of the radial and circumferential stress polygons of casting 2 revealed that, under the serviceability limit state, the circumferential and radial compressive stresses of casting 2 remained essentially unchanged with the increase of the average wall thickness at the front and rear ends of anchor cup 1. Under the ultimate limit state, the circumferential and radial compressive stresses of casting 2 showed little overall change with the increase of the relative wall thickness (load-bearing end). Analysis of the relative slip polygons of anchor cup 1 and casting 2 showed that the relative slip between anchor cup 1 and casting 2 gradually decreased with the increase of the relative wall thickness (load-bearing end).

[0186] In summary, the average wall thickness also has a significant effect on improving the stress of anchor cup 1. Increasing the wall thickness at the loaded end can effectively reduce stress, thereby improving fatigue performance and reducing the radial pressure on steel wire 3.

[0187] Coefficient of friction: The coefficient of friction refers to the friction coefficient of the contact surface between anchor cup 1 and casting body 2. The coefficient of friction of the contact surface between anchor cup 1 and casting body 2 has a significant impact on the stress distribution of anchor cup 1 and casting body 2. The coefficient of friction on the contact surface between anchor cup 1 and casting body 2 determines the ease of relative displacement between them, thus affecting the stress conditions and stress distribution.

[0188] Figures 31-34 Stress and displacement analyses of anchor cup 1 under different friction coefficients are presented. By analyzing the stress distribution of anchor cup 1 and casting 2 under normal serviceability limit state and ultimate limit state in combined models M22-M25 with different friction coefficients of the contact surface between anchor cup 1 and casting 2, the influence of the friction coefficient parameter of the contact surface between anchor cup 1 and casting 2 is determined.

[0189] like Figures 37-38 As shown, the analysis of the above two sets of results indicates that as the friction coefficient of anchor cup 1 increases, the principal tensile stress of anchor cup 1 decreases significantly; in the initial stage of the Mises stress of anchor cup 1, the principal tensile stress shows a significant decreasing trend, but as the friction coefficient of anchor cup 1 further increases, the principal tensile stress remains basically unchanged.

[0190] right Figure 34 Analysis of the radial and circumferential stress polygons of casting 2 revealed that, under the normal serviceability limit state, the circumferential compressive stress of casting 2 remained essentially unchanged, while the radial compressive stress gradually decreased with the increase of the friction coefficient of anchor cup 1. Under the ultimate limit state, the circumferential compressive stress of casting 2 did not change significantly overall, while the radial compressive stress showed a significant decrease with the increase of the friction coefficient of anchor cup 1. Analysis of the relative slip polygons of anchor cup 1 and casting 2 showed that the relative slip between anchor cup 1 and casting 2 gradually decreased with the increase of the friction coefficient of anchor cup 1.

[0191] In summary, the coefficient of friction between anchor cup 1 and casting 2 has a significant effect on improving the stress in anchor cup 1. By adjusting the coefficient of friction between anchor cup 1 and casting 2, the stress distribution in anchor cup 1 can be improved. This has a good effect on improving the principal tensile stress in anchor cup 1, helping to improve its fatigue resistance and extend its service life.

[0192] Anchor cavity structure: In the multi-level structure of anchor cavity, the internal wall thickness of the anchor cavity will vary with the depth or position to form a stepped multi-level structure.

[0193] Figures 35-38 Stress and displacement analyses of anchor cup 1 and casting body 2 under both forward and reverse multi-level anchor cavity structures are presented. By analyzing the stress distribution of anchor cup 1 and casting body 2 in combined models M26-M27 with different anchor cup 1 and anchor cavity structures under the serviceability limit state and ultimate limit state, the influence of anchor cup 1 and anchor cavity structure parameters is determined.

[0194] Depend on Figures 35-37 It is evident that the longitudinal principal tensile stress of the positive-direction multi-stage anchor cavity structure is significantly lower than that of the smooth anchor cavity and the reverse-direction multi-stage anchor cavity structure. However, at a longitudinal relative position of 0.2, the longitudinal principal tensile stress of the positive-direction multi-stage anchor cavity structure exhibits a highly significant peak. In the thickness direction, compared to the smooth anchor cavity and the reverse-direction multi-stage anchor cavity structure, the principal tensile stress of anchor cup 1 in the positive-direction multi-stage anchor cavity structure is significantly reduced; however, the Mises stress of the positive-direction multi-stage anchor cavity structure is slightly higher at the tension end of anchor cup 1 than that of the smooth anchor cavity and the reverse-direction multi-stage anchor cavity structure. As the relative position increases, the Mises stress gradually decreases until it falls below that of the smooth anchor cavity and the reverse-direction multi-stage anchor cavity structure.

[0195] right Figure 38 Analysis of the radial and circumferential stress line graphs of casting 2 revealed that, under the serviceability limit state, the circumferential and radial compressive stresses of casting 2 decreased at the endpoints of the forward multi-stage structure of the anchor cavity, significantly increased at the steps of the forward multi-stage structure, and gradually decreased again. The circumferential and radial compressive stresses of the reverse multi-stage structure of the anchor cavity remained essentially unchanged. Under the ultimate limit state, the circumferential and radial compressive stresses of casting 2 at the ports of the forward multi-stage structure of the anchor cavity showed a slight decrease, while the circumferential and radial compressive stresses at the steps showed a significant increase. At the endpoints of the reverse multi-stage structure of the anchor cavity, the circumferential compressive stress showed a slight decrease, while the radial compressive stress showed a significant increase. Analysis of the relative slip line graphs of anchor cup 1 and casting 2 showed that the relative slip between anchor cup 1 and casting 2 decreased in both the forward and reverse multi-stage structures of the anchor cavity, with the relative slip being smaller in the forward multi-stage structure.

[0196] In summary, the positive multi-stage structure of the anchor cavity has a significant effect on improving the stress of anchor cup 1. This structure moves the stress peak away from the small end, which helps improve the radial pressure on wire 3. By adding the positive multi-stage structure, the stress in anchor cup 1 is significantly improved. The reverse multi-stage structure does not improve the stress level; its main improvement is in the principal tensile stress, which helps enhance the fatigue resistance of anchor cup 1. However, more attention needs to be paid to the principal compressive stress in the reverse multi-stage structure.

[0197] Chamfering of the inner wall of anchor cup 1: Chamfering of the inner wall of anchor cup 1 refers to the process of making a chamfer by cutting at an angle at the edge or corner of the inner wall of anchor cup 1. Chamfering of the inner wall of anchor cup 1 can reduce stress concentration to a certain extent and improve the structural continuity of anchor cup 1.

[0198] Figure 39 and 40 Stress and displacement analyses of anchor cup 1 and casting 2 are presented separately for the case where the inner wall of anchor cup 1 is chamfered. Benchmark represents the structure without chamfered inner wall of anchor cup 1, while M29 represents the structure with chamfered inner wall of anchor cup 1. By analyzing the stress distribution of anchor cup 1 and casting 2 in the combined model M29 with chamfers under the serviceability limit state and ultimate limit state, the influence of chamfer parameters is determined.

[0199] like Figure 39 and 40 As shown in the figure, the analysis of the two sets of results indicates that, under both the serviceability limit state and the ultimate limit state, the presence or absence of a chamfer on the inner wall of anchor cup 1 has virtually no effect on the longitudinal principal tensile stress and the Mises stress of anchor cup 1. In the thickness direction, the presence or absence of a chamfer on the inner wall of anchor cup 1 has virtually no effect on the principal tensile stress of anchor cup 1, but the chamfer can slightly reduce the concentration of Mises stress at the stress-bearing port of anchor cup 1.

[0200] right Figure 41 Analysis of the radial and circumferential stress polygons of casting 2 revealed that, under the serviceability limit state, the circumferential and radial compressive stresses of casting 2 increase with the presence of the chamfer. Under the ultimate limit state, the circumferential and radial compressive stresses of casting 2 also increase with the presence of the chamfer. Analysis of the relative slip polygons of anchor cup 1 and casting 2 showed that the relative slip between anchor cup 1 and casting 2 remained essentially unchanged with the presence of the chamfer.

[0201] In summary, the chamfering of the inner wall of anchor cup 1 can alleviate the stress concentration phenomenon of anchor cup 1 to a certain extent, improve the structural continuity of anchor cup 1, and thus improve the reliability and service life of anchor cup 1. However, this improvement effect is not obvious.

[0202] Summary: Through the parametric modeling and analysis above, the influence of each parameter on the mechanical properties of anchor cup 1 was obtained. The table below summarizes the characteristics of the influence of each parameter.

[0203] Table 2: Summary of Parameter Influence Patterns

[0204] serial number parameter Influence Pattern degree of impact Optimization direction 1 Anchorage length Increasing the length can reduce the stress on the anchor cup 1 and improve the extrusion state of the steel wire 3. middle Maintain a reasonable economic length 2 Inner diameter of the loaded end Increasing the diameter can reduce the stress on the anchor cup 1 and improve the extrusion state of the steel wire 3. middle Maintain a reasonable economic diameter 3 Anchor cup 1 wall inclination angle Increasing the inclination angle has no significant effect on the stress on anchor cup 1 and steel wire 3. weak Maintain a reasonable economic tilt 4 Relative wall thickness of front and rear ends of anchor cup 1 Increasing the wall thickness at the loaded end can significantly reduce the stress in the anchor cup 1 and improve the extrusion state of the steel wire 3. powerful Increase the wall thickness at the loaded end and decrease the wall thickness at the free end. 5 Anchor Cup 1 Average Wall Thickness Increasing the average wall thickness can significantly reduce the stress in the anchor cup 1 and improve the extrusion state of the steel wire 3. powerful Increase wall thickness 6 Coefficient of friction between the contact surface of anchor cup 1 and casting 2 Increasing the coefficient of friction can significantly reduce the stress in the anchor cup 1 and improve the extrusion state of the steel wire 3. powerful Increase the coefficient of friction 7 Anchor Cup 1 Anchor Cavity Structure The use of a positive multi-stage conical structure can achieve the shifting of peak stress in anchor cup 1 and the peak reduction effect, thereby improving the extrusion state of steel wire 3. powerful Adopting a positive multi-stage conical inner cavity 8 Anchor Cup 1 Inner Wall Chamfer Setting a chamfer has no significant impact on the stress on anchor cup 1 and steel wire 3. weak No chamfering

[0205] Optimization of Anchor Cup 1 Structure: Based on the finite element analysis results of the above parameters such as anchorage length, inner diameter of the loaded end, inclination angle, relative wall thickness at the front and rear, average wall thickness, friction coefficient, anchor cavity structure, and chamfer of the inner wall of Anchor Cup 1, the following optimization suggestions are proposed for the parameters of Anchor Cup 1.

[0206] Table 3 Parameter Optimization Suggestions for Anchor Cup 1

[0207]

[0208] Figure 12 and 13 Stress-displacement analyses of anchor cup 1 and casting 2 after parameter optimization are presented respectively. The stress distribution of anchor cup 1 in the optimized combined model M28 is analyzed under the serviceability limit state and the ultimate limit state.

[0209] Through the Figure 12 and 13 The analysis of the two sets of results shows that, under both the serviceability limit state and the ultimate limit state, the optimized model anchor cup 1 exhibits a significant reduction in principal tensile stress and Mises stress along both the longitudinal and thickness directions. The maximum principal tensile stress and maximum Mises stress of anchor cup 1 are also improved.

[0210] right Figure 14 Analysis of the radial and circumferential stress polygons of casting 2 revealed that, under both the serviceability limit state and the ultimate limit state, the circumferential and radial compressive stresses of casting 2 decreased with the optimization of anchor cup 1. Analysis of the relative slip polygons between anchor cup 1 and casting 2 showed that the relative slip between anchor cup 1 and casting 2 decreased with the optimization of anchor cup 1.

[0211] In summary, by increasing the wall thickness, increasing the friction coefficient, and changing the anchor cavity structure to a positive multi-stage structure, the maximum principal compressive stress of the optimized anchor cup 1 increases, and the location of the maximum principal compressive stress will move away from the load-bearing end, which will improve the radial pressure at the load-bearing port and optimize the performance of the anchor cup 1 to a large extent.

[0212] To further evaluate the improvement in fatigue resistance between the optimized model and the initial model design, stress amplitude was used for evaluation and analysis. According to literature research, the steps for evaluating fatigue performance using stress amplitude are as follows: apply the load corresponding to the maximum stress (peak value) to steel wire 3 to obtain the stress distribution of the system; then apply the load corresponding to the minimum stress (valley value) to steel wire 3 to obtain the stress distribution of the system; and extract the stress difference to obtain the stress amplitude of each component. Based on experience, the maximum stress applied to steel wire 3 is 0.45 times the stress intensity, while the minimum stress is the maximum stress minus 280 MPa. Accordingly, considering the strength of steel wire 3, a maximum load of 780 kN and a minimum load of 560 kN were applied to the unoptimized model and the optimized model, respectively, and the stress distribution of the anchor cup 1 system was obtained through finite element analysis.

[0213] like Figure 11 Figure a shows a comparison of the stress valley and peak values ​​of anchor cup 1 before and after optimization. It can be seen that the stress amplitude of anchor cup 1 increased slightly after optimization, from 30.6 MPa to 35.6 MPa. On the one hand, this stress amplitude is relatively small and has little impact on the fatigue of anchor cup 1; on the other hand, the ratio of the stress valley to the peak value decreased after optimization. According to literature research, if the stress amplitudes are similar at low stress ratio levels, the fatigue strength of anchor cup 1 with a low stress ratio is relatively higher. Therefore, it can be determined that the fatigue resistance of anchor cup 1 has improved after optimization. Figure 11 Figure b shows the change in compressive stress amplitude of casting 2 before and after optimization. It can be seen that the compressive stress amplitude of casting 2 before optimization was 141 MPa, while the compressive stress amplitude after optimization decreased to 109.2 MPa. Since the compressive stress of casting 2 acts directly on steel wire 3, and the tensile stress amplitude of steel wire 3 remains unchanged before and after optimization, the comprehensive stress amplitude of steel wire 3 has been improved. The change in compressive stress of casting 2 can qualitatively determine that the fatigue resistance of steel wire 3 has also been improved.

[0214] In summary, further analysis of the anchor cup 1 structure shows that the fatigue resistance of the optimized anchor cup 1 structure and anchoring system has been improved.

[0215] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A novel cable anchoring system, characterized in that, Includes anchor cup (1) and wire strand (14), wherein: The anchor cup (1) is provided with a through main anchor cavity (6), so that one end of the main anchor cavity (6) has a front end hole (7) and the other end has a rear end hole (8). The inner wall of the main anchor cavity (6) is provided with at least two secondary frustum surfaces (10) in sequence along the through direction of the main anchor cavity (6), so that the main anchor cavity (6) forms at least two frustum anchor cavities (11), and a step transition surface (15) is provided between adjacent secondary frustum surfaces (10). Along the direction from the front end hole (7) to the rear end hole (8), the inner diameter of the secondary frustum surface (10) and the inner diameter of the step transition surface (15) both increase. The secondary frustum surface (10) is provided with pits (12) and / or protrusions (13). The main anchor cavity (6) is filled with a casting (2), which is in contact with the secondary frustum surface (10) and the step transition surface (15). The wire strand (14) passes through the front end hole (7), and at least a portion of the wire strand (14) is located inside the casting (2). The main anchor cavity (6) is also provided with a wire guide sleeve (20), the wire strand (14) passes through the wire guide sleeve (20), and the part of the wire strand (14) between the wire guide sleeve (20) and the rear end hole (8) is split into at least 3 wires (3).

2. The novel cable anchoring system according to claim 1, characterized in that: In the through direction of the main anchor cavity (6), the length of the secondary frustum surface (10) is greater than the length of the adjacent step transition surface (15).

3. The novel cable anchoring system according to claim 1, characterized in that: The secondary frustum surface (10) transitions continuously with the adjacent step transition surface (15).

4. The novel cable anchoring system according to claim 1, characterized in that: Along the direction from the front end hole (7) to the rear end hole (8): the inner diameter of the secondary frustum surface (10) gradually increases.

5. A novel cable anchoring system according to claim 1, characterized in that: Along the direction from the front end hole (7) to the rear end hole (8), the inner diameter of the stepped transition surface (15) gradually increases.

6. A novel cable anchoring system according to claim 1, characterized in that, At least two adjacent secondary frustum surfaces (10) are parallel.

7. A novel cable anchoring system according to claim 1, characterized in that: The surface (10) of the secondary frustum is roughened.

8. A novel cable anchoring system according to claim 1, characterized in that: The cross-sectional line of the secondary frustum surface (10) along the axial direction is a straight line, a circular curve, an elliptic curve, a power function curve, an exponential function curve, a hyperbola, or a spiral.

9. A novel cable anchoring system according to claim 1, characterized in that, A first protrusion (17) is provided on the step transition surface (15).

10. A novel cable anchoring system according to claim 1, characterized in that: The step transition surface (15) is provided with a concave portion (16), and the bottom of the concave portion (16) is inclined toward the front end hole (7).

11. A novel cable anchoring system according to claim 1, characterized in that: The inner wall (19) of the wire guide sleeve (20) has a continuously changing curvature along the opening direction of the wire guide sleeve (20). The part of the inner wall (19) of the wire guide sleeve (20) near the front end hole (7) is smoothly tangential to the outer wall of the corresponding part of the wire strand (14). The part of the inner wall (19) of the wire guide sleeve (20) near the rear end hole (8) is smoothly tangential to the outermost wire (3) after the wire strand (14) is split.

12. A novel cable anchoring system according to claim 11, characterized in that: The wire guide sleeve (20) is arranged in a trumpet shape.

13. A novel cable anchoring system according to claim 11, characterized in that: In the cross-sectional direction of the wire guide sleeve (20), the inner wall (19) of the wire guide sleeve (20) is in the shape of a regular polygon.

14. A novel cable anchoring system according to claim 11, characterized in that: Along the opening direction of the wire guide sleeve (20), the shape of the cross-sectional line of the inner surface of the wire guide sleeve (20) includes circular curve, elliptical curve, power function curve, exponential function curve, hyperbola or spiral.

15. A novel cable anchoring system according to claim 1, characterized in that: Along the direction from the free end to the loaded end of the anchor cup (1), the wall thickness of the anchor cup (1) gradually increases.

16. A novel cable anchoring system according to claim 1, characterized in that: The diameter of the rear end hole (8) is larger than the diameter of the front end hole (7).

17. A novel cable anchoring system according to any one of claims 1-16, characterized in that: The anchor cup (1) can be used for main cables, suspenders or stay cables.

18. A design method for the novel cable anchoring system according to any one of claims 1-17, characterized in that: Includes the following steps: S1. Determine the position of the main anchor cavity surface (9) based on the diameter of the front end hole (7) and the diameter of the rear end hole (8); S2. Determine the length of the surface (10) of each secondary frustum; S3. Determine the end position of the secondary frustum surface (10) near the front end hole (7) based on the length of the secondary frustum surface (10) and the position of the main anchor cavity surface (9); S4. Determine the angle between the secondary frustum surface (10) and the main anchor cavity surface (9); S5. Determine the angle of the step transition surface (15) relative to the secondary frustum surface (10) based on the angle of the secondary frustum surface (10) relative to the main anchor cavity surface (9).

19. A design method for the novel cable anchoring system according to any one of claims 1-17, characterized in that: Includes the following steps: A1. Analyze the influence of stress distribution results of the reference model of the cable anchoring system on the performance of the anchor cup (1) and the casting (2); A2. Combine the key parameters of the anchor cup (1) to form multiple combined models; A3. Based on each combination model, analyze the stress distribution and stress peak value of at least some key parameters on the anchor cup (1) and the casting (2) respectively, and determine the influence law of key parameters; A4. Based on the influence law of each key parameter, optimize the anchor cup (1), casting (2) and steel wire (3) to form the new cable anchoring system model; A5. Evaluate and analyze the improvement effect of the novel cable anchoring system model on fatigue resistance compared with the baseline model of the cable anchoring system.

20. The design method according to claim 19, characterized in that: The key parameters of the anchor cup (1) include the anchoring length, the diameter of the anchor cup (1), the inclination angle of the anchor cup (1) wall, the relative wall thickness of the front and rear ends of the anchor cup (1), the average wall thickness of the anchor cup (1), the friction coefficient between the casting and the anchor cup (1), the anchor cavity structure, and the chamfer of the inner wall of the anchor cup (1).

21. The design method according to claim 20, characterized in that: In step A2, the combination of key parameters of anchor cup (1) is specifically as follows: 。 22. The design method according to claim 21, characterized in that: Step A3 is as follows: By analyzing the stress distribution and stress peak of anchor cup (1) and casting (2) with different anchor lengths in the combined models M1-M4 under normal service limit state and bearing capacity limit state, the influence law of anchor length parameter is determined. By analyzing the stress distribution and stress peak values ​​of anchor cup (1) and casting (2) with different inner diameters of the loaded end in combination models M5-M8 under normal service limit state and ultimate bearing capacity state, the influence law of the inner diameter parameter of the loaded end is determined. By analyzing the stress distribution of anchor cup (1) and casting (2) with different anchor cup (1) wall inclination angles in combination models M9-M13 under normal service limit state and bearing capacity limit state, the influence law of anchor cup (1) wall inclination angle parameter is determined. By analyzing the stress distribution of anchor cup (1) and casting (2) with different relative wall thicknesses at the front and rear ends of the anchor cup (1) in the combined models M14-M17 under normal service limit state and bearing capacity limit state, the influence law of relative wall thickness parameters at the front and rear ends of the anchor cup (1) is determined. By analyzing the stress distribution of anchor cup (1) and casting (2) with different average wall thicknesses at the front and rear ends of the combined model M18-M21 under normal service limit state and bearing capacity limit state, the influence law of the average wall thickness parameter at the front and rear ends of anchor cup (1) is determined. By analyzing the stress distribution of anchor cup (1) and casting body (2) with different friction coefficients of the contact surface between anchor cup (1) and casting body (2) in combination models M22-M25 under normal service limit state and bearing capacity limit state, the influence law of the friction coefficient parameter of the contact surface between anchor cup (1) and casting body (2) is determined. By analyzing the stress distribution of anchor cup (1) and casting (2) with different anchor cup (1) and anchor cavity structure in combination models M26-M27 under normal service limit state and bearing capacity limit state, the influence law of anchor cup (1) anchor cavity structure parameters is determined. By analyzing the stress distribution of the anchor cup (1) and casting (2) of the combined model M29 with chamfers under the normal service limit state and the ultimate limit state of bearing capacity, the influence law of chamfer parameters is determined.

23. The design method according to claim 22, characterized in that: The specific influence patterns of key parameters are as follows: 。

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