A fatigue-resistant arc-shaped damping element that provides high damping force and its application

Abstract

This invention relates to a fatigue-resistant arc-shaped damping element capable of providing high damping force and its application. The arc-shaped damping element is made of austenitic steel, has an arc-shaped geometry, and has pin holes at both ends. Its cross-sectional shape is rectangular. The yield strength of the austenitic steel is not less than 420 MPa; under tensile or compressive elastoplastic deformation, the deformation mechanism of the austenitic structure is mainly dislocation plane slip mechanism; under conditions of 1% strain amplitude, -1 strain ratio, and a loading frequency of 0.1–0.2 Hz, the fatigue life of the austenitic steel is not less than 1800 cycles. In terms of geometry, the width of the arc-shaped damping element gradually decreases or remains constant from the middle section of the arc towards the pin holes; the ratio of the maximum width of the arc-shaped damping element to the radius of its central arc surface is between 1 / 10 and 1 / 3; the central angle corresponding to the central arc surface between the pin holes at both ends is between 180° and 215°. The arc-shaped damping element of this invention can provide high damping force while also possessing good fatigue performance and a simple and compact structure.

Description

Technical Field

[0001] This invention belongs to the field of seismic engineering technology, and in particular relates to a fatigue-resistant arc-shaped damping element that can provide high damping force and its application. Background Technology

[0002] Tough metals have good plastic deformation capacity and exhibit excellent hysteresis characteristics (i.e., plastic energy dissipation characteristics) under repeated loading, and are therefore used to manufacture different types of metal energy dissipation shock absorbers.

[0003] In bridge vibration control, C-type and E-type steel dampers are installed between the superstructure and substructure of the bridge to provide tensile restraint and dissipate external vibration energy. Currently, the metal materials used to manufacture bridge dampers are typically low-yield-point steel and high-yield-strength carbon structural steel (such as Q355B). Both of these steels are ferritic steels; under alternating loads, fatigue damage usually begins and propagates earlier from stress and strain concentration points, lodged slip zones, and dislocation cellular structures within the ferritic steel material, ultimately leading to fatigue failure and a low fatigue life. Furthermore, as the strength of ferritic steel increases, its fatigue life during repeated plastic deformation typically decreases accordingly. Therefore, steel dampers made from the aforementioned ferritic steel materials often fail to meet fatigue resistance requirements under certain operating conditions.

[0004] In bridge structures, the installation of steel dampers, such as C-shaped steel, is often affected by the available space. For example, in high-intensity seismic zones, there are significant displacement requirements for the dampers, necessitating the design of larger ferritic steel dampers to meet the requirements of damping displacement and damping force. However, bridge structures are often constrained by the space between the pier top and the beam bottom, making it impossible to design and use existing ferritic steel dampers, or their spatial layout is inflexible. Therefore, when using steel dampers to achieve energy dissipation and vibration reduction, reducing the size of the steel dampers helps to enhance the flexibility of their installation and use.

[0005] Low-layer-fault-energy Fe-Mn-Si austenitic alloy steels possess excellent fatigue resistance and have the potential to be used to manufacture damping units (such as C-shaped steel) for steel dampers, thereby extending the service life of steel dampers. However, the yield strength of these low-layer-fault-energy Fe-Mn-Si austenitic alloy steels is relatively low (typically significantly lower than 350–400 MPa); when the damping unit needs to provide a large damping force, the cross-sectional area of ​​the damping unit must also increase, which will also lead to an increase in the required installation space for the damper and inflexible spatial layout of the steel damper. Currently, low-layer-fault-energy Fe-Mn-Si austenitic alloy steels have not been used to manufacture C-shaped steel dampers.

[0006] In summary, given the unfavorable properties of existing C-shaped steel and other steel damping materials (low fatigue resistance of ferritic steel and low yield strength of low stacking fault energy Fe-Mn-Si austenitic alloy steel) and the unfavorable properties of existing C-shaped steel and other steel dampers (poor fatigue performance, or large structural size and large installation space requirements), there is an urgent need to develop C-shaped steel dampers that can provide large damping force, have good fatigue performance, and have a simple and compact structure. These dampers can be applied to bridge bearings to achieve tensile limiting and energy dissipation and vibration reduction functions, and can also achieve miniaturization and lightweighting of steel dampers. Summary of the Invention

[0007] Given that existing C-shaped steel dampers cannot simultaneously achieve high damping force, good fatigue performance, and simple and compact structure, the present invention provides, in its first aspect, a fatigue-resistant arc-shaped damping element that can provide high damping force, and in its second aspect, the application of the aforementioned arc-shaped damping element.

[0008] The arc-shaped damping element provided by this invention has the advantages of good fatigue performance, simple and compact structure, and the ability to provide large damping force.

[0009] The objective of this invention can be achieved through the following technical solutions.

[0010] The first aspect of the present invention provides a fatigue-resistant arc-shaped damping element that can provide high damping force.

[0011] A fatigue-resistant arc-shaped damping element that can provide high damping force is made of austenitic steel, has an arc-shaped geometry, a rectangular cross-section, and pin holes at both ends.

[0012] The austenitic steel has a yield strength of not less than 420 MPa and a fracture elongation of not less than 30%; when the strain amplitude of the periodic alternating tensile-compression elastoplastic deformation is 1%, the strain ratio is -1, and the loading frequency is 0.1 to 0.2 Hz, the fatigue life of the austenitic steel is not less than 1800 cycles.

[0013] The microstructure of the austenitic steel consists of austenite, ferrite with a volume fraction not exceeding 10%, and dispersed precipitates with a volume fraction not exceeding 15%. During tensile or compressive elastoplastic deformation, the deformation mechanism of the austenitic structure is mainly dislocation plane slip mechanism. The average grain size of the austenitic structure is not greater than 250 μm. The dispersed precipitates play a role in strengthening the austenitic matrix, and their average size is not greater than 1 μm.

[0014] In the geometry of the arc-shaped damping element, the width b of the arc-shaped damping element gradually decreases or remains constant from the middle section of the arc towards the adjacent pin hole, wherein the middle section of the arc has the maximum width b. max The portion adjacent to the pin hole has a minimum width b min bmin With b max The ratio is between 1 / 3 and 1.0; b max The ratio of the radius r of the central arc surface of the damping element to the radius of the central arc surface is between 1 / 10 and 1 / 3; the central angle 360° - θ corresponding to the central arc surface between the two end pin holes is between 180° and 215°; the diameter of the pin hole is b. min 0.5 to 1.0 times.

[0015] When the width b of the arc-shaped damping element remains constant, b = b max =b min The arc-shaped damping element has a rectangular cross-section.

[0016] Based on the above selection of austenitic steel material and geometric design, the design damping displacement of the fatigue-resistant arc-shaped damping element is not less than 0.3 times the center distance L of the pin holes at both ends of the arc-shaped damping element; and, under this design damping displacement condition, when the loading frequency is not less than 0.01Hz, the arc-shaped damping element can complete at least 25 cycles of periodic alternating tensile-compression elastoplastic deformation with a damping force attenuation of less than 15%; thereafter, under the condition of 1.2 times the design damping displacement, when the loading frequency is not less than 0.01Hz, the arc-shaped damping element can continue to complete at least 3 cycles of periodic alternating tensile-compression elastoplastic deformation with a damping force attenuation of less than 15%.

[0017] In this invention, the central arc surface of the arc-shaped damping element is defined as a fan-shaped surface that is equidistant from the inner and outer edge surfaces of the arc-shaped damping element, and its radius is denoted as r; the width of the arc-shaped damping element is defined as the distance between the inner and outer edge surfaces of the damping element along the radial direction of the aforementioned fan-shaped surface.

[0018] In this invention, the design damping displacement, damping force, and damping force symmetry of the arc-shaped damping element are defined as follows.

[0019] The design damping displacement refers to the maximum allowable tensile displacement (also the maximum compressive displacement) of the arc-shaped damping element under cyclic tensile and compressive deformation. Furthermore, under this maximum tensile (or compressive) displacement condition, with a loading frequency not lower than 0.01 Hz, the arc-shaped damping element can complete at least 25 cycles of periodic alternating tensile-compression elastoplastic deformation with a damping force attenuation of less than 15%. Subsequently, under 1.2 times the design damping displacement condition, with a loading frequency not lower than 0.01 Hz, the arc-shaped damping element can continue to complete at least 3 cycles of periodic alternating tensile-compression elastoplastic deformation with a damping force attenuation of less than 15%. Damping displacement refers to the tensile (or compressive) displacement of the arc-shaped damping element when it undergoes cyclic tensile and compressive deformation to absorb and dissipate external vibration energy. Damping force refers to the tensile load and compressive load borne by the arc-shaped damping element when it undergoes tensile and compressive deformation to absorb and dissipate external vibration energy. Damping force symmetry refers to the degree of closeness between the tensile load and the compressive load borne by the arc-shaped damping element under a certain damping displacement condition. It is expressed by the relative difference (=(tensile load-compressive load) / average value of tensile load and compressive load). A small relative difference between the two indicates good damping force symmetry, and vice versa.

[0020] This invention specifies that the material of the fatigue-resistant arc-shaped damping element is austenitic steel. The microstructure of the austenitic steel consists of austenite, ferrite with a volume fraction not exceeding 10%, and dispersed precipitates with a volume fraction not exceeding 15%. During tensile or compressive elastoplastic deformation, the deformation mechanism of the austenitic structure is primarily dislocation plane slip. This microstructural feature reduces the formation of internal defects in the austenitic steel and delays the propagation of fatigue cracks, enabling the austenitic steel to exhibit good low-cycle fatigue performance, thereby enhancing the low-cycle fatigue performance and cumulative plastic deformation capacity of the arc-shaped damping element. This invention limits the average grain size of the austenitic structure to no more than 250 μm, the purpose of which is to reduce the risk of fatigue crack initiation and propagation along austenite grain boundaries (when the average grain size of austenite exceeds 250 μm, the risk of fatigue crack initiation and propagation along austenite grain boundaries increases significantly). This invention limits the austenitic steel to contain no more than 10% ferrite by volume; when the ferrite content is too high, the fatigue resistance of the austenitic steel will be significantly reduced. The dispersed precipitates distributed in the austenitic steel matrix help increase the strength of the austenitic steel and improve the damping force provided by the damping element. This invention limits the austenitic steel matrix to contain no more than 15% precipitates by volume, and the average size of the precipitated reinforcing phase is no greater than 1 μm; excessive content and excessively large precipitates will cause strain localization and the initiation of fatigue cracks. This invention strictly limits the microstructure of the austenitic steel to ensure that the austenitic steel and damping element can withstand large strain fatigue deformation without premature fatigue failure.

[0021] The present invention specifies that the yield strength of austenitic steel is not less than 420 MPa and the elongation at break is not less than 30%; when the strain amplitude of the periodic alternating tensile-compression elastoplastic deformation is 1%, the strain ratio is -1 and the loading frequency is 0.1 to 0.2 Hz, the fatigue life of austenitic steel is not less than 1800 cycles. The main purpose of limiting the mechanical properties of austenitic steel is to ensure that the material has high strength, good plastic deformation capacity, and fatigue performance, so that the arc-shaped damping element can provide a large damping force and have the following large design damping displacement and fatigue performance: the design damping displacement is not less than 0.3 times the center distance of the pin holes at both ends of the arc-shaped damping element; under this design damping displacement condition, when the loading frequency is not less than 0.01Hz, the arc-shaped damping element can complete at least 25 cycles of periodic alternating tensile-compression elastoplastic deformation with a damping force attenuation of less than 15%; thereafter, under the condition of 1.2 times the design damping displacement, when the loading frequency is not less than 0.01Hz, the arc-shaped damping element can continue to complete at least 3 cycles of periodic alternating tensile-compression elastoplastic deformation with a damping force attenuation of less than 15%.

[0022] In the geometry of the arc-shaped damping element of this invention, the width b of the arc-shaped damping element gradually decreases from the middle section of the arc towards the pin holes at both ends (i.e., the damping element has a variable cross-section structure) or remains constant (i.e., the damping element has a constant cross-section structure). This geometric design allows all parts of the arc-shaped damping element to effectively participate in yield deformation and plastic energy dissipation; conversely, if this is not done, significant strain concentration will occur in the damping element, thereby reducing its energy dissipation efficiency. In this invention, the middle section of the arc has the maximum width b. max The portion adjacent to the pin hole has a minimum width b min b min With b max The ratio is between 1 / 3 and 1.0. When b min With b max When the ratio approaches 1 / 3, the stress-strain distribution of the arc-shaped damping element is relatively uniform during elastoplastic deformation, and the design damping displacement of the damping element is large (compared to the arc-shaped damping element with uniform cross-section); when b min With b max When the ratio approaches 1, the arc-shaped damping element can provide greater damping force, and the symmetry of the damping force is better at large damping displacements (compared to the variable cross-section arc-shaped damping element).

[0023] This invention limits the maximum width b of the arc-shaped damping element. max The ratio of the radius r of the central arc surface to the radius of the central arc surface is between 1 / 10 and 1 / 3; the central angle 360° - θ corresponding to the central arc surface between the pin holes at both ends is between 180° and 215°. When the maximum width b of the damping element... maxWhen the ratio of the radius to the central arc surface is less than 1 / 10, the plastic deformation and damping force provided by the damping element are small, and the good fatigue resistance of the austenitic steel material of the damping element cannot be fully utilized. When the maximum width b of the arc-shaped damping element... max When the ratio of the radius to the central arc surface is greater than 1 / 3, the plastic deformation in the middle section and its vicinity of the damping element is relatively large. This will cause the damping element to be unable to complete 25 cycles of alternating tensile-compressive elastoplastic deformation with a damping force attenuation of less than 15% under the target design damping displacement (≥ 0.3 times the center distance L of the pin holes at both ends of the damping element); or, the damping element to be unable to simultaneously meet the requirements of 25 cycles of fatigue deformation under the target design damping displacement and 3 cycles of fatigue deformation under 1.2 times the target design damping displacement. Therefore, this invention limits the maximum width b of the arc-shaped damping element. max The ratio of the radius to the central arc surface is between 1 / 10 and 1 / 3. Furthermore, when the central angle (360° - θ) corresponding to the central arc surface between the pin holes at both ends of the arc-shaped damping element is less than 180°, the damping force symmetry of the damping element at large damping displacements is poor. When the central angle (360° - θ) corresponding to the central arc surface between the pin holes at both ends of the arc-shaped damping element is greater than 215°, due to the limited center distance between the pin holes at both ends, the arc-shaped damping element cannot fully utilize its deformation energy dissipation function, resulting in an overly redundant structural dimension design. Therefore, this invention limits the central angle (360° - θ) corresponding to the central arc surface between the pin holes at both ends of the arc-shaped damping element to between 180° and 215°.

[0024] Compared with existing variable rectangular cross-section arc-shaped damping elements (the damping element is made of ferritic steel), the rectangular cross-section arc-shaped damping element of the present invention has the following advantages:

[0025] 1) Small radius of the central arc surface. Because it is made of austenitic steel with excellent fatigue performance (the material's fatigue performance is significantly better than that of ferritic low-yield-point steel and high-strength carbon structural steel used in existing damping elements), the damping element of this invention can withstand greater periodic cyclic elasto-plastic deformation strain and more cycles of cyclic elasto-plastic deformation. For the same design damping displacement, the radius of the central arc surface of the arc-shaped damping element of this invention can be more than 10% smaller than that of existing arc-shaped damping elements. This means the planar dimensions of the arc-shaped damping element of this invention can be significantly reduced, thereby achieving miniaturization and weight reduction of the damping element, saving installation space. Furthermore, reducing the radius of the central arc surface of the damping element can increase plastic deformation strain and damping force, reduce yield displacement, and make the fatigue deformation hysteresis curve fuller.

[0026] 2) The width of the arc-shaped damping element can be increased. As the width of the damping element increases, the deformation strain it withstands also increases. Similarly, because austenitic steel can withstand greater periodic reciprocating plastic deformation strain, for the same central arc radius, the width of the arc-shaped damping element of this invention can be larger than that of existing ferritic steel arc-shaped damping elements. Increasing the width of the damping element helps to increase the damping force, reduce the yield displacement, and increase the fullness of the hysteresis curve. It should be noted that although the width of the damping element is increased, its miniaturization and weight reduction can still be achieved due to the significant reduction in its central arc radius.

[0027] 3) Greater damping force. The austenitic steel material of the arc-shaped damping element of this invention has higher yield strength and tensile strength (compared to ferritic steel, the material of existing damping elements), and it easily exhibits higher cyclic work hardening behavior during strain fatigue deformation. Therefore, in terms of material properties, the damping element of this invention can provide greater damping force.

[0028] 4) When the arc-shaped damping element has a rectangular cross-section, it helps to improve the symmetry of the damping force and the fullness of the deformation hysteresis curve. Although the variable cross-section feature can make the stress and strain distribution on the arc-shaped damping element better uniform during deformation, the rectangular cross-section feature can make the damping force provided by the arc-shaped damping element at large damping displacement more symmetrical and the deformation hysteresis curve fuller.

[0029] 5) When the arc-shaped damping element has a uniform rectangular cross-section structure, it helps to reduce the manufacturing cost of the damping element. The uniform rectangular cross-section arc-shaped damping element of the present invention can be manufactured by bending forming, and the material utilization rate is close to 100%; in comparison, existing variable cross-section arc-shaped damping elements are often obtained by cutting steel plates, and the material utilization rate is usually low (less than 50%). Therefore, the manufacturing cost of the damping element with the uniform rectangular cross-section structure in the present invention will be significantly reduced.

[0030] In one embodiment of the present invention, the mass percentage of the chemical composition of the austenitic steel is defined as follows: 15% ≤ Mn ≤ 40%, 6.0% ≤ Al ≤ 13.0%, 0.6% ≤ C ≤ 1.3%, Si ≤ 3.0%, Cr ≤ 3.0%, Ni ≤ 6.0%, Ti ≤ 1.0%, Nb ≤ 1.0%, V ≤ 1.0%, P ≤ 0.15%, S ≤ 0.03%, N ≤ 0.03%, with the remainder being Fe and unavoidable impurity elements.

[0031] Austenitic steel meeting the above composition requirements has the following microstructure characteristics: the microstructure comprises austenite, ferrite with a volume fraction not exceeding 10%, and precipitates with a volume fraction not exceeding 15%. Due to its high Al and Mn content, austenite possesses high stacking fault energy; during tensile or compressive elastoplastic deformation, the deformation mechanism of the austenitic structure is primarily dislocation plane slip, thus giving austenitic steel excellent low-cycle fatigue performance, thereby enhancing the low-cycle fatigue performance and cumulative plastic deformation capacity of arc-shaped damping elements. As can be seen from the above composition, the precipitates distributed in the austenitic matrix may include κ carbides (intermediate compounds formed by Fe, Mn, Al, and C elements); intermediate compounds formed by Ni and Al elements; and carbide particles formed by the combination of Ti, Nb, V, and C elements. The volume fraction of the above precipitates is controlled to not exceed 15%, and the average size of the precipitates is controlled to not exceed 1 μm. Furthermore, due to the high Al content in the above composition, austenitic steel exhibits good atmospheric corrosion resistance.

[0032] Without altering the basic microstructure characteristics, the chemical composition of austenitic steel may also contain a small amount of Cu; the present invention limits the mass percentage of Cu to: Cu≤2%.

[0033] When the alloy composition and microstructure characteristics described above are present, the yield strength of austenitic steel is not less than 420 MPa and the elongation at break is not less than 30%; when the strain amplitude of the periodic alternating tensile-compression deformation is 1%, the strain ratio is -1 and the loading frequency is 0.1 to 0.2 Hz, the fatigue life of austenitic steel is not less than 1800 cycles.

[0034] Furthermore, in another embodiment of the present invention, the mass percentage of the chemical composition of the austenitic steel is defined as follows: 30% < Mn ≤ 40%, 6.0% ≤ Al ≤ 11.0%, 0.6% ≤ C ≤ 1.2%, 0.6% < Si ≤ 3.0%, 1.0% < Cr ≤ 3.0%, Ti ≤ 1.0%, Nb ≤ 1.0%, V ≤ 1.0%, P ≤ 0.15%, S ≤ 0.03%, N ≤ 0.03%, with the remainder being Fe and unavoidable impurity elements.

[0035] Austenitic steel meeting the above composition requirements has the following microstructure characteristics: the microstructure comprises austenite, ferrite with a volume fraction not exceeding 10%, and precipitates with a volume fraction not exceeding 10%. Due to its high Al and Mn content, austenite possesses high stacking fault energy; during tensile or compressive elastoplastic deformation, the deformation mechanism of the austenitic structure is primarily dislocation plane slip, thus giving austenitic steel excellent low-cycle fatigue performance, thereby enhancing the low-cycle fatigue performance and cumulative plastic deformation capacity of the arc-shaped damping element. As can be seen from the above composition, the precipitated reinforcing phases distributed in the austenitic matrix may include κ carbides (intermediate compounds formed by Fe, Mn, Al, and C elements), and carbide particles formed by the combination of Ti, Nb, V, and C elements. The volume fraction of the above-mentioned precipitated reinforcing phases is controlled to not exceed 10%, and the average size of the precipitates is controlled to not exceed 1 μm.

[0036] When the alloy composition and microstructure characteristics described above are present, the yield strength of austenitic steel is not less than 420 MPa and the elongation at break is not less than 30%; when the strain amplitude of the periodic alternating tensile-compression deformation is 1%, the strain ratio is -1 and the loading frequency is 0.1 to 0.2 Hz, the fatigue life of austenitic steel is not less than 2000 cycles.

[0037] The fatigue-resistant arc-shaped damping element described in this invention also includes the common C-shaped steel damper.

[0038] The second aspect of the present invention provides the application of the above-mentioned fatigue-resistant arc-shaped damping element that can provide high damping force.

[0039] The arc-shaped damping elements can be used individually or in combination. When used in combination, the arc-shaped damping elements are stacked together to form a damping unit group, which is connected together by pins passing through pin holes at both ends. Additionally, the arc-shaped damping elements or damping unit groups can be used in pairs, meaning that under damping displacement, one arc-shaped damping element or damping unit group is under tension while the other is under compression.

[0040] The arc-shaped damping element is connected to the bridge support via a connector, serving to limit tension and dissipate external vibration energy. The arc-shaped damping element is connected to the connector via a pin at the pin hole.

[0041] The present invention further provides a damping unit group formed by stacking and overlapping the arc-shaped damping elements.

[0042] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0043] 1. The arc-shaped damping element of the present invention has the characteristics of small size, large design damping displacement, and large damping force.

[0044] 2. The arc-shaped damping element with a rectangular cross-section of the present invention has the advantages of good damping force symmetry, compact structure, simple manufacturing method and low manufacturing cost.

[0045] 3. The fatigue-resistant arc-shaped damping element of the present invention is easy to miniaturize and lighten, can adapt to the large transverse displacement requirements of bridges in high-intensity seismic isolation areas, and requires little installation space and is easy to maintain later.

[0046] 4. The fatigue-resistant arc-shaped damping element of the present invention has good resistance to atmospheric corrosion.

[0047] It should be noted that the austenitic steel material of the present invention, which has the aforementioned mechanical properties, microstructure characteristics, and composition range, can also be used to manufacture steel dampers of any other geometric shape, such as E-type steel dampers, to improve the seismic protection performance of buildings and bridges. Attached Figure Description

[0048] Figure 1 This is a three-dimensional structural schematic diagram of a variable rectangular cross-section arc-shaped damping element;

[0049] Figure 2 This is a schematic diagram of the main structure of a variable rectangular cross-section arc-shaped damping element;

[0050] Figure 3 This is a side view of a variable rectangular cross-section arc-shaped damping element.

[0051] Figure 4 This is a three-dimensional structural schematic diagram of an arc-shaped vibration damping element with an equal rectangular cross-section;

[0052] Figure 5 This is a schematic diagram of the main structure of an arc-shaped damping element with an equal rectangular cross-section;

[0053] Figure 6 This is a three-dimensional structural diagram of a damping unit group formed by stacking and overlapping arc-shaped damping elements.

[0054] The meanings of the labels in the figure are as follows: 1- Variable rectangular cross-section arc damping element, 2- Central arc surface of variable rectangular cross-section arc damping element, 3- Pin hole of variable rectangular cross-section arc damping element, 4- Equal rectangular cross-section arc damping element, 5- Central arc surface of equal rectangular cross-section arc damping element, 6- Pin hole of equal rectangular cross-section arc damping element. Detailed Implementation

[0055] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0056] Example 1

[0057] A variable rectangular cross-section arc-shaped damping element, made of austenitic steel, with a geometry as follows: Figure 1 Three-dimensional structural diagram Figure 2 Main view and Figure 3 As shown in the side view.

[0058] The austenitic steel material of the arc-shaped damping element has the following chemical composition by mass percentage: 0.88% C, 1.01% Si, 30.1% Mn, 9.2% Al, 1.1% Cr, 0.02% P, 0.006% S, 0.009% N, 0.014% P, with the remainder being Fe and unavoidable impurities. The microstructure of the austenitic steel contains only austenite, with an austenite grain size of 68 μm. The mechanical properties of the austenitic steel are: yield strength 540 MPa, elongation at break 62%; and low-cycle fatigue life of 4483 cycles when subjected to cyclic alternating tensile-compression elastoplastic deformation with a strain amplitude of 1%, a strain ratio of -1, and a loading frequency of 0.1 Hz.

[0059] Depend on Figure 2 The main view shown and Figure 3 As shown in the side view, the geometry of the variable rectangular cross-section arc-shaped damping element 1 is as follows: the radius r of the central arc surface 2 of the variable rectangular cross-section arc-shaped damping element is 495 mm; the width b of the middle section of the arc is... max =76mm, width b of the area adjacent to the pin hole min =45mm, part b between the two m1 =72mm and b m2 =60mm (along the arc direction, the angle between adjacent feature width sections is 30°, such as b) max Width portion and b m1 The included angle between the width portions is 30°; the central angle 360° - θ corresponding to the center arc surface between the two end pin holes 3 is approximately 208°; the diameter of the pin hole 3 of the variable rectangular cross-section arc damping element is 38mm; the center distance between the two end pin holes L = 960mm; the thickness h of the variable rectangular cross-section arc damping element 1 is 55mm.

[0060] The designed damping displacement of the aforementioned arc-shaped damping element is 450 mm (approximately 0.47 times the center distance L between the pin holes at both ends of the arc-shaped damping element). Under this designed damping displacement condition, at a loading frequency of 0.03 Hz, the arc-shaped damping element completes 30 cycles of cyclic alternating tensile-compression elastoplastic deformation with a damping force attenuation of less than 15%. Subsequently, under a damping displacement of 1.2 times the design displacement (i.e., a damping displacement of 540 mm), at a loading frequency of 0.03 Hz, the arc-shaped damping element continues to complete 3 cycles of cyclic alternating tensile-compression elastoplastic deformation with a damping force attenuation of less than 15%. At this point, the arc-shaped damping unit still has not cracked or failed. When the applied damping displacement is the design damping displacement (=450mm), the tensile damping force is 112KN, the compressive damping force is 68KN, the average value of the tensile and compressive damping forces = (tensile damping force + compressive damping force) / 2 = (112+68) / 2KN = 90KN, and the relative difference in damping force = (tensile damping force - compressive damping force) / average value of the tensile and compressive damping forces = 49%.

[0061] Example 2

[0062] A type of arc-shaped damping element with a rectangular cross-section, made of austenitic steel, has the following geometry: Figure 4 3D structural diagram and Figure 5 The main view is shown.

[0063] The austenitic steel material of the arc-shaped damping element has the following chemical composition by mass percentage: 0.88% C, 1.01% Si, 30.1% Mn, 9.2% Al, 1.1% Cr, 0.02% P, 0.006% S, 0.009% N, 0.014% P, with the remainder being Fe and unavoidable impurities. The microstructure of the austenitic steel contains only austenite, with an austenite grain size of 68 μm. The mechanical properties of the austenitic steel are: yield strength 540 MPa, elongation at break 62%; and low-cycle fatigue life of 4483 cycles when subjected to cyclic alternating tensile-compression elastoplastic deformation with a strain amplitude of 1%, a strain ratio of -1, and a loading frequency of 0.1 Hz.

[0064] Depend on Figure 5 As shown in the front view, the geometry of the rectangular cross-section arc-shaped damping element 4 is as follows: the radius r of the central arc surface 5 of the rectangular cross-section arc-shaped damping element is 495 mm; the width b of the rectangular cross-section arc-shaped damping element is 76 mm; the central angle 360° - θ corresponding to the central arc surface between the two end pin holes is approximately 208°; the diameter of the rectangular cross-section arc-shaped pin hole 6 is 38 mm; the center distance L between the two end pin holes 6 is 960 mm; and the thickness h of the arc-shaped damping element 4 is 55 mm.

[0065] The designed damping displacement of the aforementioned arc-shaped damping element is 400 mm (approximately 0.42 times the center distance L between the pin holes at both ends of the arc-shaped damping element). Under this designed damping displacement condition, at a loading frequency of 0.03 Hz, the arc-shaped damping element completes 30 cycles of cyclic alternating tensile-compression elastoplastic deformation with a damping force attenuation of less than 15%. Subsequently, under a damping displacement of 1.2 times the design displacement (i.e., a damping displacement of 480 mm), at a loading frequency of 0.03 Hz, the arc-shaped damping element continues to complete 3 cycles of cyclic alternating tensile-compression elastoplastic deformation with a damping force attenuation of less than 15%. At this point, the arc-shaped damping unit still has not cracked or failed. When the applied damping displacement is the design damping displacement (=400mm), the tensile damping force is 124KN, the compressive damping force is 108KN, and the average value of the tensile and compressive damping forces = (tensile damping force + compressive damping force) / 2 = (124 + 108) / 2KN = 116KN. The relative difference in damping force = (tensile damping force - compressive damping force) / average value of tensile and compressive damping forces = 13.8%. Compared with Example 1, the damping force provided by the uniform rectangular cross-section damping element in this example has better symmetry; however, the variable rectangular cross-section damping element in Example 1 often provides a larger damping displacement.

[0066] In engineering applications, the aforementioned arc-shaped damping elements are typically used in combination. When used in combination, multiple arc-shaped damping elements are stacked together to form a damping unit group, such as... Figure 6 As shown, the damping unit groups are connected together by pins passing through the pin holes at both ends. The average value of the tensile and compressive damping forces acting on the damping unit groups is the average damping force provided by a single damping element multiplied by the number of damping elements.

[0067] Examples 3-6

[0068] The arc-shaped damping element with a uniform rectangular cross-section is made of austenitic steel, and the composition of its main alloying elements is shown in Table 1. The austenitic steel contains 0.008%–0.02% S, 0.006%–0.02% N, and 0.009%–0.15% P, and also contains some unavoidable trace impurities. The mechanical properties and microstructure characteristics of the austenitic steel material of the arc-shaped damping element are shown in Table 2.

[0069] The geometry of the arc-shaped damping element is as follows: Figure 4 3D structural diagram and Figure 5 The front view is shown. The radius of the central arc surface of the arc-shaped damping element is r, the width is b, the central angle corresponding to the central arc surface between the two end pin holes is 360° - θ, the diameter of the pin hole is 0.5b, and the center distance between the two end pin holes is L. The specific planar dimensions of each damping element are shown in Table 3. The thickness of each damping element is approximately 55mm.

[0070] Table 4 shows the design damping displacement, fatigue deformation performance, average tensile and compressive damping forces under the design damping displacement condition, and damping force symmetry (expressed by the relative difference between tensile and compressive damping forces) of each arc-shaped damping element. As can be seen from Table 4, the aforementioned arc-shaped damping elements exhibit characteristics of large design damping displacement, good fatigue performance, and good damping force symmetry.

[0071] Table 1. Mass percentage (wt%) of alloying elements in austenitic steel, a material with a uniform rectangular cross-section for arc-shaped damping elements.

[0072] C Mn Al Si Cr Ti Nb V Example 3 0.60 38.8 6.6 1.5 1.1 / / / Example 4 1.18 31.0 10.4 2.9 1.6 / 0.93 / Example 5 0.82 32.2 8.0 0.65 1.2 / / / Example 6 0.82 30.8 7.8 0.9 2.3 / / /

[0073] Table 2 Mechanical properties and microstructure of austenitic steel, the material of arc-shaped damping elements with equal rectangular cross-sections.

[0074]

[0075] Table 3 Planar geometric dimensions of arc-shaped damping elements with equal rectangular cross-sections

[0076]

[0077]

[0078] Table 4. Design damping displacement, fatigue deformation performance, and damping force of arc-shaped vibration damping elements with equal rectangular cross-sections.

[0079]

[0080] Examples 7-11

[0081] The arc-shaped damping element with a variable rectangular cross-section is made of austenitic steel, and the composition of its main alloying elements is shown in Table 5. The austenitic steel contains 0.008%–0.02% S, 0.006%–0.02% N, and 0.009%–0.15% P, and also contains some unavoidable trace impurities. The mechanical properties and microstructure characteristics of the austenitic steel material of the arc-shaped damping element are shown in Table 6.

[0082] The geometry of the arc-shaped damping element is as follows: Figure 1 3D structural diagram and Figure 2 The front view shows the arc-shaped damping element. The radius of the central arc surface of the arc-shaped damping element is r, and its width b is between b... max ~b min (Width feature value includes b) max 、b m1 、b m2 and b minAlong the arc direction, the angle between adjacent feature width portions is 30°, such as b. max Width portion and b m1 The included angle between the width sections is 30°; the central angle corresponding to the center arc surface between the pin holes at both ends is 360° - θ; the diameter of the pin hole is b. min The center distance between the pin holes at both ends is L. The specific planar dimensions of each damping element are shown in Table 7. The thickness of each damping element is approximately 55mm.

[0083] Table 8 shows the design damping displacement, fatigue deformation performance, average tensile and compressive damping forces under the design damping displacement condition, and damping force symmetry (expressed by the relative difference between tensile and compressive damping forces) of each arc-shaped damping element. As can be seen from Table 8, the aforementioned arc-shaped damping elements exhibit large design damping displacement and excellent fatigue performance.

[0084] Table 5. Mass percentage (wt%) of alloying elements in austenitic steel, material of variable rectangular cross-section arc-shaped damping elements.

[0085] C Mn Al Si Cr Ni Ti Nb V Example 7 1.30 32.0 10.8 1.5 / / / / / Example 8 1.20 22.3 12.6 / 3.0 / / / / Example 9 0.88 16.4 9.2 / / 4.8 / / / Example 10 1.15 35.1 8.8 1.5 2.5 / 0.96 / / Example 11 1.10 34.8 7.5 2.3 2.0 / / / 0.94

[0086] Table 6. Mechanical and microstructure of austenitic steel, material of variable rectangular cross-section arc-shaped vibration element.

[0087]

[0088]

[0089] Table 7 Planar geometric dimensions of curved damping elements with variable rectangular cross-section

[0090]

[0091]

[0092] Table 8. Design damping displacement, fatigue deformation performance, and damping force of arc-shaped vibration damping elements with variable rectangular cross-sections.

[0093]

[0094]

[0095] Comparative Example 1

[0096] A variable rectangular cross-section arc-shaped vibration damping element is made of Q355B ferritic structural steel, with the following chemical composition by mass percentage: 0.18% C, 0.33% Si, 1.35% Mn, and the remainder being Fe and unavoidable impurity elements. The geometry of the variable rectangular cross-section arc-shaped vibration damping element is as follows. Figure 2As shown, the radius of the central arc surface of the arc-shaped damping element is r = 495 mm; the width of the middle section of the arc is b. max =76mm, width b of the area adjacent to the pin hole min =45mm, part b between the two m1 =72mm and b m2 =60mm (along the arc direction, the angle between adjacent feature width sections is 30°, such as b) max Width portion and b m1 The included angle between the width sections is 30°; the central angle corresponding to the center arc surface between the pin holes at both ends is approximately 208° (360° - θ). The diameter of the pin hole is 38mm, and the center distance between the pin holes at both ends is L = 960mm. The thickness of the arc-shaped damping element is h = 55mm.

[0097] The material of the above-mentioned variable rectangular cross-section arc damping element has the following mechanical properties: yield strength of about 370 MPa and elongation at break of about 27%; when the strain amplitude of the periodic alternating tensile-compression elastoplastic deformation is 1%, the strain ratio is -1 and the loading frequency is 0.1 Hz, the fatigue life of the Q355B material is less than 1120 cycles.

[0098] The aforementioned variable rectangular cross-section arc-shaped damping element underwent periodic alternating tensile-compression elastoplastic deformation under conditions of a damping displacement of 450 mm and a loading frequency of 0.03 Hz. With increasing cycle count, the damping force remained essentially constant, reaching an average of approximately 58.5 kN for both tensile and compressive damping forces at the 13th cycle. Upon continued cyclic deformation, localized deformation gradually began at the center of the arc-shaped damping element, leading to a decrease in damping force. Compared to Example 1, the fatigue deformation capacity and damping force provided by the ferritic steel variable rectangular cross-section arc-shaped damping element in this comparative example were significantly lower than those of the austenitic steel variable rectangular cross-section arc-shaped damping element in Example 1.

[0099] Comparative Example 2

[0100] A rectangular cross-section arc-shaped damping element with a thickness of 55 mm is disclosed. The steel plate is made of Q355B ferritic structural steel, with the following chemical composition by mass percentage: 0.18% C, 0.33% Si, 1.35% Mn, and the remainder being Fe and unavoidable impurity elements. The geometry of the rectangular cross-section arc-shaped damping element is as follows. Figure 5 As shown, the radius of the central arc surface of the arc-shaped damping element is r = 495 mm, the width is 76 mm, the central angle 360° - θ between the central arc surfaces of the two end pin holes is approximately 208°, and the center distance between the two end pin holes is L = 960 mm.

[0101] The material of the above-mentioned rectangular cross-section arc-shaped damping element has the following mechanical properties: yield strength of about 370 MPa and elongation at break of about 27%; when the strain amplitude of the periodic alternating tensile-compression elastoplastic deformation is 1%, the strain ratio is -1 and the loading frequency is 0.1 Hz, the fatigue life of the Q355B material is less than 1120 cycles.

[0102] The aforementioned rectangular cross-section arc-shaped damping element underwent periodic alternating tensile-compression elastoplastic deformation under a damping displacement of 375 mm and a loading frequency of 0.03 Hz. After the 12th cycle of deformation, obvious local deformation and edge cracks appeared in the center of the arc-shaped damping element. When fatigue deformation was continued at a damping displacement of 375 mm, the damping force rapidly decreased by more than 20%, at which point the arc-shaped damping element was determined to have failed. Compared with Example 2, the fatigue deformation capacity of the ferritic steel rectangular cross-section arc-shaped damping element in this comparative example is significantly lower than that of the austenitic steel rectangular cross-section arc-shaped damping element in Example 2.

[0103] Comparative Example 3

[0104] A rectangular cross-section arc-shaped damping element, approximately 55 mm thick, is made of austenitic steel. The austenitic steel has the following chemical composition by mass percentage: 1.4% C, 24.5% Mn, 13.8% Al, 4% Cr, with the remainder being Fe and unavoidable impurities. The planar geometry of the rectangular cross-section arc-shaped damping element is as follows... Figure 5 As shown, the radius of the central arc surface of the arc-shaped damping element is r = 495 mm, the width is b = 76 mm, the central angle 360° - θ between the central arc surfaces of the two end pin holes is approximately 208°, and the center distance between the two end pin holes is L = 960 mm.

[0105] The austenitic steel material of the uniform rectangular cross-section arc-shaped damping element has the following mechanical and microstructural characteristics: yield strength of approximately 1215 MPa and elongation at break of approximately 18%; when subjected to periodic alternating tensile-compression elasto-plastic deformation with a strain amplitude of 1%, a strain ratio of -1, and a loading frequency of 0.1 Hz, the fatigue life of the austenitic steel is approximately 1475 cycles. The microstructure of the austenitic steel consists of austenite, a small amount of ferrite, and carbides.

[0106] The aforementioned rectangular cross-section arc-shaped damping element underwent periodic alternating tensile-compression elasto-plastic deformation under a target design damping displacement of 270 mm and a loading frequency of 0.03 Hz. The target design damping displacement is approximately 0.28 times the center distance between the pin holes at both ends of the damping element. The rectangular cross-section arc-shaped damping element failed to complete 25 cycles of fatigue deformation under this target design damping displacement condition, which is equivalent to the design damping displacement of the damping element being significantly less than 0.3 times the center distance between the pin holes at both ends of the damping element.

[0107] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A fatigue-resistant arc-shaped damping element capable of providing high damping force, characterized in that, The arc-shaped damping element (1) is made of austenitic steel, and its geometry is an arc structure with a rectangular cross-section. It has pin holes (3) at both ends. The austenitic steel has a yield strength of not less than 420 MPa and a fracture elongation of not less than 30%; when the strain amplitude of the periodic alternating tensile-compression elastoplastic deformation is 1%, the strain ratio is -1 and the loading frequency is 0.1~0.2 Hz, the fatigue life of the austenitic steel is not less than 1800 cycles. The microstructure of the austenitic steel consists of austenite, ferrite with a volume fraction not exceeding 10%, and dispersed precipitates with a volume fraction not exceeding 15%. During tensile or compressive elastoplastic deformation, the deformation mechanism of the austenitic structure is mainly dislocation plane slip mechanism. The average grain size of the austenitic structure is not greater than 250 μm. The dispersed precipitates play a role in strengthening the austenitic matrix, and their average size is not greater than 1 μm. In the geometry of the arc-shaped damping element (1), the width b of the arc-shaped damping element (1) gradually decreases or remains constant from the middle section of the arc towards the adjacent pin hole, wherein the middle section of the arc has the maximum width b. max The portion adjacent to the pin hole has a minimum width b min b min With b max The ratio is between 1 / 3 and 1.0; the width b of the middle section of the arc. max The ratio of the radius r of the central arc surface (2) of the damping element to the radius r of the central arc surface (2) is between 1 / 10 and 1 / 3; the central angle 360° - θ corresponding to the central arc surface between the two pin holes (3) is between 180° and 215°; the diameter of the pin hole (3) is b. min 0.5 to 1.0 times; The design damping displacement of the arc-shaped damping element (1) is not less than 0.3 times the center distance L of the pin holes (3) at both ends of the arc-shaped damping element (1); under this design damping displacement condition, when the loading frequency is not less than 0.01Hz, the arc-shaped damping element (1) can complete at least 25 cycles of periodic alternating tensile-compression elastoplastic deformation and the damping force decay is less than 15%; thereafter, under the condition of 1.2 times the design damping displacement, when the loading frequency is not less than 0.01Hz, the arc-shaped damping element (1) can continue to complete at least 3 cycles of periodic alternating tensile-compression elastoplastic deformation and the damping force decay is less than 15%.

2. The fatigue-resistant arc-shaped damping element capable of providing high damping force according to claim 1, characterized in that, The arc-shaped damping element has a geometric shape of a sector-shaped ring with a uniform rectangular cross-section, meaning the width b of the arc-shaped damping element remains constant, b = b. max =b min .

3. The fatigue-resistant arc-shaped damping element capable of providing high damping force according to claim 1, characterized in that, The austenitic steel has the following chemical composition by mass percentage: 15%≤Mn≤40%, 6.0%≤Al≤13.0%, 0.6%≤C≤1.3%, Si≤3.0%, Cr≤3.0%, Ni≤6.0%, Ti≤1.0%, Nb≤1.0%, V≤1.0%, P≤0.15%, S≤0.03%, N≤0.03%, with the remainder being Fe and unavoidable impurity elements.

4. The fatigue-resistant arc-shaped damping element capable of providing high damping force according to claim 3, characterized in that, The austenitic steel has the following chemical composition by mass percentage: 30% < Mn ≤ 40%, 6.0% ≤ Al ≤ 11.0%, 0.6% ≤ C ≤ 1.2%, 0.6% < Si ≤ 3.0%, 1.0% < Cr ≤ 3.0%, Ti ≤ 1.0%, Nb ≤ 1.0%, V ≤ 1.0%, P ≤ 0.15%, S ≤ 0.03%, N ≤ 0.03%, with the remainder being Fe and unavoidable impurity elements.

5. A fatigue-resistant arc-shaped damping element capable of providing high damping force according to claim 3 or 4, characterized in that, Without altering the basic microstructure characteristics, the austenitic steel also contains Cu in its chemical composition, with a mass percentage of Cu ≤ 2%.

6. The application of the fatigue-resistant arc-shaped damping element that provides high damping force as described in claim 1, characterized in that, The arc-shaped damping element can be used alone or in combination; When used in combination, the arc-shaped damping elements are stacked together to form a damping unit group, which is connected together by pins passing through pin holes at both ends. The arc-shaped damping element or the damping unit group formed by stacking and overlapping arc-shaped damping elements is connected to the bridge bearing via a connector, which plays the role of tensile limiting and dissipating external vibration energy; the arc-shaped damping element or the damping unit group is connected to the connector via a pin at the pin hole.

7. The application of the fatigue-resistant arc-shaped damping element capable of providing high damping force according to claim 6, characterized in that, The arc-shaped damping elements or damping units are used in pairs, that is, under the action of damping displacement, one arc-shaped damping element or damping unit group is under tension while the other damping element or damping unit group is under compression.

8. A damping unit group formed by stacking and overlapping fatigue-resistant arc-shaped damping elements as described in claim 1, which can provide high damping force.

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