Composite loading device and loading method capable of correcting posture of I-shaped beam

Abstract

The invention belongs to the technical field of bridge structure test loading devices, and discloses a composite loading device capable of rectifying the posture of an I-beam and a loading method.The composite loading device comprises a plurality of surface external loading devices evenly arranged in the axial direction of an I-beam test piece and a longitudinal loading device arranged in the center of the top surface of the I-beam test piece; the surface external loading device comprises two-way jacks on two sides of a web of the I-beam test piece, the two-way jacks are respectively an inward pulling jack and an outward pushing jack, and the end parts of the jacks are connected with an upper flange plate or a lower flange plate of the I-beam test piece; forces applied by the inward pulling jack and the outward pushing jack are equal in magnitude but opposite in direction; the axial spacing L of the jacks is consistent with the transverse spacing T; one end of the I-beam test piece is erected on the fixed hinged support, and the other end of the I-beam test piece is erected on the sliding hinged support; leveling platforms are arranged between the hinged supports and the I-shaped beam test pieces; and the axis of the leveling platform is parallel to the axis of the I-beam test piece. According to the invention, transverse and longitudinal composite loading can be realized, the transverse posture of the beam body can be corrected, and the stress working condition of the beam body can be truly simulated.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of bridge structure test loading device, and particularly relates to a composite loading device capable of correcting the attitude of an I-beam and a loading method. BACKGROUND

[0002] The statements in this section merely provide background information related to the present application and do not necessarily constitute prior art.

[0003] Concrete thin-webbed beams are widely used in bridge engineering due to their excellent mechanical properties and structural efficiency, such as concrete box beams and I-beams. In actual working conditions, such beams have typical spatial stress characteristics. For example, the web, as a key load transmission component, not only bears the overall bending and shear effect along the longitudinal direction of the bridge, but also bears additional transverse out-of-plane bending moments from the vehicle load on the bridge deck, the temperature difference between the inside and outside of the box, and other load actions. The additional out-of-plane bending moments generate gradient distribution of vertical normal stress in the thickness direction of the web, which in turn disturbs the principal stress state on the inside and outside of the web and affects the overall safety of the structure.

[0004] The prior art discloses a loading device for I-shaped girder web distortion fatigue test, which comprises a base, a test beam arranged on the base, an X-shaped cross brace or a K-shaped cross brace arranged on the side surface of the test beam, a transmission assembly arranged at the free end of the X-shaped cross brace or the K-shaped cross brace, and a servo hydraulic actuator arranged on the transmission assembly. The servo hydraulic actuator applies a horizontal out-of-plane action to the vertical stiffening ribs and the horizontal node plate of the test beam through the transmission assembly and the X-shaped cross brace or the K-shaped cross brace, so as to simulate the distortion fatigue effect of the I-shaped girder at the web gap due to different deflection differences under the action of vehicle eccentric load.

[0005] The above scheme has the following defects: Only the specific area (web gap) of the test piece is tested for horizontal out-of-plane action, and it is impossible to apply uniform transverse out-of-plane bending moment to the web of the I-shaped beam, and it is also impossible to realize the composite loading of transverse out-of-plane bending moment and longitudinal in-plane bending shear, so it is difficult to truly simulate the composite stress working condition of the beam under the action of multiple source loads, and the test personnel cannot make correct judgments on the performance and safety of the test component. In addition, the I-shaped beam of the above scheme is directly fixed on the base, and the bending deformation of the I-shaped beam in the length direction or the width direction during actual loading is not considered. This excessive constraint will interfere with the internal force balance of the I-shaped beam test piece, resulting in inaccurate test data. SUMMARY

[0006] Therefore, the present application aims to provide a composite loading device and loading method for correcting the attitude of an I-beam, which can solve the technical problem that the prior art cannot apply uniform transverse out-of-plane bending moment to the web of an I-beam specimen, cannot realize composite loading of transverse out-of-plane bending moment and longitudinal in-plane bending shear, and causes excessive constraint to result in inaccurate test data.

[0007] To achieve the above object, the present application adopts the following technical solutions: In a first aspect, the present application provides a composite loading device for correcting the attitude of an I-beam, which comprises a plurality of out-of-plane loading devices arranged uniformly along the axial direction of an I-beam specimen and a longitudinal loading device at the center of the top surface of the I-beam specimen. The out-of-plane loading device comprises bidirectional jacks arranged on both sides of the web of the I-beam specimen, which are respectively an inner pulling jack and an outer pushing jack, and the end of the jack is connected to the upper flange plate or the lower flange plate of the I-beam specimen; the force applied by the inner pulling jack and the outer pushing jack is equal in magnitude but opposite in direction; the axial spacing L of the jack is consistent with the transverse spacing T. The longitudinal loading device comprises a loading ball seat at the center of the top surface of the I-beam specimen, and the top surface of the loading ball seat is connected to an actuator perpendicular to the I-beam specimen. One end of the I-beam specimen is erected on a fixed hinge support, and the other end is erected on a sliding hinge support; a regulating platform is arranged between the hinge support and the I-beam specimen; and the axis of the regulating platform is parallel to the axis of the I-beam specimen.

[0008] Preferably, the regulating platform comprises a slidingly connected arc-shaped base and a swing platform, the bottom surface of the swing platform is provided with an arc-shaped groove, the top surface of the arc-shaped groove is provided with a worm gear groove, a worm is rotatably connected in the arc-shaped base and engages with the worm gear groove, a stepping motor is installed on the side surface of the arc-shaped base, and the output shaft of the stepping motor is fixedly connected with the worm.

[0009] Preferably, an inclinometer is installed on the upper flange plate and the lower flange plate; a PLC controller is also installed on the arc-shaped base, the inclinometer is connected to the communication interface of the PLC controller, and the PLC controller is electrically connected to the stepping motor.

[0010] Preferably, the fixed hinge support or the sliding hinge support comprises a base, a roller is placed on the base, and a top plate is fixedly connected to the roller; a limiting strip is placed on both sides of the roller of the fixed hinge support and fixedly connected to the base, and no limiting strip is arranged on both sides of the roller of the sliding hinge support; the regulating platform is fixedly connected to the top plate, and a buffer air bag is arranged on both sides of the regulating platform.

[0011] Preferably, a temporary support rod is also arranged on the axial side of the fixed hinge support or the sliding hinge support, the top end of the temporary support rod is bolted to the top plate, and the bottom end is bolted to the base, thereby limiting the rotation of the fixed hinge support or the sliding hinge support.

[0012] Preferably, edges of the upper flange plate and the lower flange plate are provided with position corresponding reserved holes, both ends of the inner pulling jack are fixedly connected with ear rings, both ends of the outer pushing jack are fixedly connected with universal ball plates, and the ear rings or the universal ball plates are connected with the reserved holes through the inner pulling connectors or end plates.

[0013] Preferably, the inner pulling connector comprises a U-shaped fork and a pin bolt, the U-shaped fork is provided with a pin bolt hole matched with the ear ring, the ear ring is inserted into the U-shaped fork in alignment and then the pin bolt is inserted; a first threaded hole is formed at an end of the U-shaped fork away from the ear ring, and the first threaded hole is threadedly connected with a flange bolt in the reserved hole.

[0014] Preferably, a plurality of second threaded holes are uniformly formed at edges of the universal ball plate and the end plate, and the second threaded holes are threadedly connected with fixing bolts; a circular through hole and a hexagonal cavity are formed at a center of the end plate, a head of the flange bolt is left in the hexagonal cavity, a rod of the flange bolt passes through the circular through hole, the reserved hole and a round hole of the pad, and is threadedly connected with a nut on a top surface or a bottom surface of the I-beam flange plate.

[0015] In the second aspect, a loading method of the composite loading device for correcting the posture of the I-beam is provided, and the specific steps are as follows: Symmetrical and equidistant reserved holes are reserved when the I-beam test piece is manufactured, and an inclinometer is installed; A buffer air bag is arranged on the hinged support, and a regulating platform is fixed, the I-beam test piece is erected on the regulating platform during installation, and the hinged support is locked by a temporary support rod; the inclinometer and the regulating platform are connected, the posture of the I-beam test piece is adjusted by the regulating platform, and the posture is locked; The out-of-plane loading device and the longitudinal loading device are assembled in sequence; and the temporary support rod is removed to start loading; During loading, the I-beam test piece can be subjected to longitudinal in-plane bending shear and transverse out-of-plane bending moment loading simultaneously, or single mode loading can be performed first, and then the composite loading is performed. During the composite loading, the regulating platform adjusts the transverse posture of the I-beam test piece in real time according to the detection results of the two inclinometers; and the loading data when the web oblique cracks appear and when the I-beam test piece is damaged are recorded.

[0016] Preferably, the longitudinal loading device adopts force control at the initial stage of loading, and adopts displacement control when the I-beam test piece is close to failure; and the out-of-plane loading device adopts force control.

[0017] Compared with the prior art, the present application has the advantages and positive effects that: The composite loading device for the posture of the I-beam capable of deviation correction of the application can realize the uniform transverse bending moment applied to the web of the I-beam test piece, the vertical force applied to the I-beam test piece by the actuator for longitudinal in-plane bending shear loading, the transverse out-of-plane bending moment applied to the web of the I-beam test piece by the out-of-plane loading device, no mutual interference between the two loading modes, normal work at the same time, real simulation of the composite stress working condition of the beam body, and convenience for the test personnel to make correct judgment on the performance and test safety of the test component.

[0018] In addition, the I-beam test piece is placed on the hinged support to provide the longitudinal bending rotation freedom of the I-beam test piece to adapt to the longitudinal bending deformation requirement of the I-beam test piece during loading, and the adjusting platform is used to correct the lateral deviation of the loading ball seat during the installation and composite loading of the I-beam test piece, eliminate the lateral deviation of the loading ball seat, and avoid the additional torque interference with the test results due to the deviation of the vertical force; the hinged support and the adjusting platform work independently, can simultaneously meet the deformation constraint requirement of the beam end for the longitudinal in-plane bending shear and the transverse out-of-plane bending moment loading, and improve the reliability of the test results. BRIEF DESCRIPTION OF DRAWINGS

[0019] The drawings accompanying the specification of the application form a part of the application and serve to further provide a further understanding of the application, the illustrative embodiments of the application and the explanations thereof serve to explain the application and do not constitute an improper limitation of the application.

[0020] Figure 1 is a front view of a composite loading device for the posture of the I-beam capable of deviation correction of the application embodiment 1 or the application embodiment 2; Figure 2 is a rear view of a composite loading device for the posture of the I-beam capable of deviation correction of the application embodiment 1 or the application embodiment 2; Figure 3 is a top view of a composite loading device for the posture of the I-beam capable of deviation correction of the application embodiment 1 or the application embodiment 2; Figure 4 is a sectional view of the A-A section of the composite loading device for the posture of the I-beam capable of deviation correction of the application embodiment 1 or the application embodiment 2; Figure 1 is a sectional view of the B-B section of the composite loading device for the posture of the I-beam capable of deviation correction of the application embodiment 1 or the application embodiment 2; Figure 5 Figure 1 is a sectional view of the C-C section of the composite loading device for the posture of the I-beam capable of deviation correction of the application embodiment 1 or the application embodiment 2; Figure 6 is a three-dimensional view of the adjusting platform of the application embodiment 1 or the application embodiment 2; Figure 1 is a side view of the adjusting platform of the application embodiment 1 or the application embodiment 2; Figure 7 Figure 8 Figure 9 ​​​is a sectional view along the worm shaft axis of the adjusting platform of the embodiment 1 or the embodiment 2 of the present application; Figure 10 is a schematic view of the worm gear groove meshing with the worm of the embodiment 1 or the embodiment 2 of the present application; Figure 11 is a front view of the inner pull connector of the embodiment 1 or the embodiment 2 of the present application; Figure 12 is a side view of the inner pull connector of the embodiment 1 or the embodiment 2 of the present application; Figure 13 is a top view of the end plate of the embodiment 1 or the embodiment 2 of the present application; Figure 14 is a side view of the end plate of the embodiment 1 or the embodiment 2 of the present application; Figure 15 is a side view of the I-beam test specimen transverse bending deformation of the embodiment 1 or the embodiment 2 of the present application; Figure 16 is a side view of the I-beam test specimen transverse posture adjustment of the embodiment 1 or the embodiment 2 of the present application; in the figure: 1, I-beam test specimen; 2, fixed hinge support; 21, roller shaft; 22, limiting strip; 23, temporary support rod; 3, sliding hinge support; 4, adjusting platform; 41, swing table; 42, arc-shaped base; 43, stepping motor; 44, communication interface; 45, sliding block guide rail; 46, worm gear groove; 47, worm; 5, support pad; 6, loading ball seat; 7, inner pull jack; 71, ear ring; 8, outer push jack; 81, universal ball disc; 9, inner pull connector; 91, U-shaped fork; 92, first threaded hole; 93, pin hole; 94, pin; 10, end plate; 101, circular through hole; 102, hexagonal cavity; 103, second threaded hole; 11, reserved hole; 12, flange bolt; 13, nut; 14, pad; 15, buffer air bag; 16, first inclinometer; 17, second inclinometer. DETAILED DESCRIPTION

[0021] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present application. Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs.

[0022] The present application will be described in detail below with reference to the accompanying drawings.

[0023] Embodiment 1 The present embodiment discloses a composite loading device capable of correcting the attitude of an I-beam, like Figure 1 , Figure 2 , Figure 3As shown, it includes several out-of-plane loading devices uniformly arranged along the axial direction of the I-beam specimen 1, and a longitudinal loading device at the center of the top surface of the I-beam specimen 1. Figure 1 , Figure 2 , Figure 4 As shown, the longitudinal loading device includes a loading ball seat 6 at the center of the top surface of the I-beam specimen 1. An actuator is connected to the top surface of the loading ball seat 6. The actuator cooperates with the reaction frame (not shown in the figure). The actuator applies a vertical force Fn to the I-beam specimen 1 perpendicular to the I-beam specimen 1, forming a longitudinal in-plane bending-shear loading mode.

[0024] like Figure 1 , Figure 2 , Figure 4 As shown, the out-of-plane loading device includes bidirectional jacks installed on both sides of the web of the I-beam specimen 1, namely an inward-pulling jack 7 and an outward-pushing jack 8. The two ends of each jack are connected to the upper and lower flange plates of the I-beam specimen 1, respectively. The inward-pulling jack 7 causes the upper and lower flange plates to contract inwards, applying an inward pulling force to the flange of the I-beam specimen 1. The outward-pushing jack 8 causes the upper and lower flange plates to tension outwards, applying an outward pushing force to the flange of the I-beam specimen 1. It should be noted that the forces applied by the inward-pulling jack 7 and the outward-pushing jack 8 are equal in magnitude. In this embodiment, by simultaneously applying inward pulling and outward pushing forces to both sides of the I-beam specimen 1, forces of equal magnitude and opposite direction are generated, achieving vertical internal force self-balancing and generating only lateral out-of-plane bending moments, thus eliminating interference with longitudinal loading.

[0025] In this embodiment, as Figure 3 As shown, the axial spacing L of the jacks is consistent with the transverse spacing T. The axial spacing L refers to the axial direction along the I-beam specimen 1, and the transverse spacing T refers to the width direction along the I-beam specimen 1. This arrangement ensures that the loading force applied by the jacks is evenly applied to the flange plate of the I-beam specimen 1 and diffuses along a 45° angle to the web plate of the I-beam specimen 1, thereby generating a uniform transverse out-of-plane bending moment and forming a transverse out-of-plane loading mode. It can be understood that by using both the longitudinal loading device and the out-of-plane loading device to load the I-beam specimen 1, a composite loading of transverse out-of-plane bending moment and longitudinal in-plane bending shear can be achieved.

[0026] like Figure 1 , Figure 2 As shown, both ends of the I-beam specimen 1 are mounted on hinged supports, and the axis of the hinged supports is parallel to the axis of the I-beam specimen 1. The hinged supports include a fixed hinged support 2 and a sliding hinged support 3. One end of the I-beam specimen 1 is mounted on the fixed hinged support 2, and the other end is mounted on the sliding hinged support 3.

[0027] It should be noted that the hinged support not only provides a stable support base for the I-beam test piece, but also allows the end of the I-beam test piece 1 to rotate around the roll shaft, providing the I-beam test piece 1 with a longitudinal bending rotation freedom to adapt to the longitudinal bending deformation requirement of the I-beam test piece 1 under loading, avoiding excessive constraint to generate additional bending moment, and improving the reliability of the test results. The sliding hinge support 3 can provide axial displacement freedom to adapt to the expansion displacement caused by loading, avoiding the accumulation of axial force due to limited displacement.

[0028] As shown in Figure 1 , Figure 5 , Figure 6 , the hinged support and the end bottom surface of the I-beam test piece 1 are provided with adjusting platforms 4. In this embodiment, the hinged support and the end bottom surface of the I-beam test piece 1 are provided with adjusting platforms 4, and the axis of the swing table 41 is parallel to the axis of the I-beam test piece 1. When the I-beam test piece 1 deflects laterally on both sides, the I-beam test piece 1 is adjusted by the adjusting platform 4.

[0029] It should be noted that the adjusting platform 4 dynamically adjusts the lateral attitude of the I-beam test piece 1 during composite loading, so that the loading ball seat 6 and the adjusting platform 4 are always in the same vertical plane, avoiding additional torque on the I-beam test piece 1 due to vertical force deviation, and interfering with the test results. The out-of-plane loading device and the longitudinal loading device are arranged in a structure that not only ensures the uniformity of the lateral out-of-plane bending moment, but also avoids interference of the longitudinal loading by the lateral deformation, thereby truly simulating the spatial stress behavior of the I-beam test piece (bridge) under complex working conditions, solving the problems of the prior art that the I-beam test piece web cannot be subjected to uniform lateral out-of-plane bending moment, the lateral out-of-plane bending moment and longitudinal in-plane bending shear composite loading cannot be achieved, and the test data is inaccurate due to deformation interference during loading.

[0030] As shown in Figure 7 to Figure 9 , the adjusting platform 4 includes an arc-shaped base 42, the bottom surface of the swing table 41 is an arc-shaped surface, and the swing table 41 and the arc-shaped base 42 are slidably connected through two arc-shaped sliding block guides 45 arranged in parallel along the axial direction. Between the two sliding block guides 45, the bottom surface of the swing table 41 is provided with an arc-shaped groove, and the top surface of the arc-shaped groove is provided with a worm gear groove 46. In this embodiment, the sliding block guides 45 are fixedly connected to the arc-shaped base 42, and the sliding blocks are fixedly connected to the bottom surface of the swing table 41.

[0031] As shown in Figure 9 , the arc-shaped base 42 is rotatably connected to a worm 47, and the axis of the worm 47 is perpendicular to the center of the arc-shaped base 42; as shown in Figure 9 , Figure 10 , the worm 47 is engaged with the worm gear groove 46 on the top surface of the arc-shaped groove. It can be understood that when the worm 47 rotates, it will drive the worm gear groove 46 to rotate, thereby driving the swing table 41 to slide relative to the arc-shaped base 42, and further changing the angle of the top surface of the swing table 41 relative to the vertical line.

[0032] As shown in Figure 7 , the side of the arc-shaped base 42 is provided with a stepping motor 43, and the output shaft of the stepping motor 43 is fixedly connected with a worm 47; the position of the swing table 41 relative to the arc-shaped base 42 can be adjusted by controlling the forward and reverse rotation of the stepping motor 43.

[0033] It can be understood that when the out-of-plane loading device loads the I-beam test piece 1, as shown in Figure 15 , the I-beam test piece 1 may be deflected transversely when a transverse out-of-plane bending moment is applied, resulting in inconsistent inclination angles of the upper flange and the lower flange, causing the vertical force to deviate and generate an additional torque on the I-beam test piece 1, interfering with the accuracy of the longitudinal in-plane bending and shearing load, and further affecting the authenticity of the test results. During the loading process, as shown in Figure 16 , the balance of the transverse posture of the I-beam test piece 1 is maintained by adjusting the angle of the swing table 41, so that the loading ball seat 6 and the swing table 41 are always in the vertical plane, avoiding the generation of an additional torque on the I-beam test piece 1 due to the deviation of the vertical force, and interfering with the test results.

[0034] As shown in Figure 15 , Figure 16 , a first inclinometer 16 is installed on the upper flange plate at both ends of the I-beam test piece 1, and a second inclinometer 17 is installed on the lower flange plate, and the two inclinometers are used to obtain the inclination angle of the I-beam test piece 1. It should be noted that, as shown in Figure 7 , in this embodiment, a PLC controller is also installed on the arc-shaped base 42, and the first inclinometer 16 and the second inclinometer 17 are connected to the communication interface 44 of the PLC controller for transmitting the monitored inclination angle to the PLC controller, and the PLC controller is electrically connected to the stepping motor 43 for controlling the forward or reverse rotation or shutdown of the stepping motor 43.

[0035] It should be noted that the working conditions of the stepping motor 43 are set in the PLC controller: when the sum of the first inclinometer 16 and the second inclinometer 17 is not zero, the stepping motor 43 is started. During the transverse out-of-plane bending moment loading process, the I-beam test piece 1 will be transversely bent (as shown in Figure 15 ), causing the first inclinometer 16 on the upper flange to have an accelerating increasing trend, and then triggering the working of the adjusting platform 4 to real-time correct the transverse posture of the I-beam test piece 1, so that the values of the first inclinometer 16 and the second inclinometer 17 are equal and opposite (as shown in Figure 16 ).

[0036] It should be noted that in this embodiment, the top surface of the swing table 41 is fixedly connected with the support pad 5 to increase the force receiving area with the I-beam test piece 1, and the adjusting platform 4 is fixedly connected on the hinged support.

[0037] In this embodiment, the transverse bending moment is 100 kN·m. ; In the formula: F is the force applied by the jack; L is the axial spacing of the jack; T is the lateral spacing of the jack; and θ is the average angle of rotation of the upper flange plate and the lower flange plate of the I-beam test piece 1 after lateral bending deformation.

[0038] As shown in Figure 1 , Figure 2 , Figure 5 , Figure 6 , the fixed hinge support 2 or the sliding hinge support 3 each includes a base on which a roller shaft 21 is placed, the roller shaft is fixedly connected with a top plate, the top plate is fixedly connected with an adjusting platform, the end surface of the I-beam test piece 1 is placed on the top plate of the adjusting platform, and the roller shaft 21 is perpendicular to the axis of the I-beam test piece 1, so that the end of the I-beam test piece 1 rotates axially around the roller shaft 21.

[0039] In this embodiment, as shown in Figure 1 , Figure 5 , limit strips 22 are placed on both sides of the roller shaft 21 of the fixed hinge support 2 along the axial direction of the I-beam test piece 1, the limit strips 22 are fixedly connected (such as welded) with the base, so that the roller shaft 21 can only rotate axially between the limit strips 22 and cannot move in the horizontal direction. As shown in Figure 1 , Figure 6 , no limit strips are arranged on both sides of the roller shaft 21 of the sliding hinge support 3, so that the sliding hinge support 3 can move in the horizontal direction.

[0040] As shown in Figure 1 , Figure 5 , Figure 6 , a buffer air bag 15 is arranged on the top surface of the fixed hinge support 2 or the sliding hinge support 3 and on both sides of the adjusting platform 4. The buffer air bag 15 prevents the I-beam test piece 1 from overturning during installation and loading. It should be noted that, in order to avoid test interference, a set initial gap (in this embodiment, the gap is controlled to be 1-3 cm) is left between the buffer air bag 15 and the bottom surface of the I-beam test piece 1. When the I-beam test piece 1 rotates laterally, the bottom surface of the I-beam test piece 1 contacts the buffer air bag 15, and the buffer air bag 15 gradually works.

[0041] It should be further noted that the buffer air bag 15 is an air spring, which makes the buffer air bag 15 have a variable stiffness characteristic, that is, at the beginning of work, the elastic stiffness of the buffer air bag 15 is small, and the influence on the lateral bending deformation of the I-beam test piece 1 and the normal work of the adjusting platform 4 is small, but when the I-beam test piece 1 has a large rotation angle that may cause overturning risk, the buffer air bag 15 can provide a large stiffness to prevent accidents.

[0042] As shown in Figure 1 , Figure 2 , Figure 5 ,Figure 6 As shown in the drawings, a temporary support rod 23 is arranged on the axial side of the hinge support, the top end of the temporary support rod 23 is bolted to the top plate of the hinge support, the bottom end of the temporary support rod 23 is bolted to the base, and the hinge support can be limited to rotate. It should be noted that during the installation of the I-beam test piece 1, the temporary support rod 23 is installed on the axial side of the hinge support, so that the hinge support can be locked to prevent rotation, and after the I-beam test piece 1 is installed in place and before loading, the temporary support rod 23 can be removed.

[0043] In this embodiment, the I-beam test piece 1 adopts a reinforced concrete structure. As shown in the drawings, Figure 3 The edge positions of the upper flange plate and the lower flange plate of the I-beam test piece 1 are provided with position corresponding reserved holes 11, the reserved holes 11 are uniformly arranged along the axial direction of the I-beam test piece 1, and the reserved holes 11 are symmetrically distributed with respect to the web of the I-beam test piece 1, the axial spacing and the transverse spacing of the reserved holes 11 are consistent, in this embodiment, the reserved holes can be circular steel pipes reserved before concrete pouring, or can be drilled and formed after pouring. The reserved holes 11 are used to connect the bidirectional jack and realize the positioning function.

[0044] In this embodiment, the two ends of the jack are hinged to the flange plate of the I-beam test piece 1. Specifically, as shown in the drawings, Figure 1 , Figure 4 The top end and the bottom end of the inner pulling jack 7 are fixedly connected with the ear ring 71, and are connected with the I-beam test piece 1 through the inner pulling connecting piece 9 and the flange bolt 12.

[0045] As shown in the drawings, Figure 11 , Figure 12 The inner pulling connecting piece 9 includes a U-shaped fork 91 and a pin 94, the U-shaped fork 91 is provided with a pin hole 93 matched with the ear ring 71, the ear ring 71 is inserted into the U-shaped fork 91 and aligned, and then the pin 94 is inserted, so that the two ends of the inner pulling jack 7 are hinged to the inner pulling connecting piece 9. A first threaded hole 92 is formed at the end of the U-shaped fork 91 away from the ear ring 71, and the first threaded hole 92 is threadedly connected with the flange bolt 12 in the reserved hole 11. The gusset plate 14 is arranged between the bolt head of the flange bolt 12 and the flange plate, so as to increase the stress area of the flange bolt 12 and the flange plate, and avoid stress concentration at the bolt head of the flange bolt 12.

[0046] As shown in the drawings, Figure 4 The top end and the bottom end of the outer pushing jack 8 are fixedly connected with the universal ball disc 81, and the side of the universal ball disc 81 away from the outer pushing jack 8 is bolted to the end plate 10. As shown in the drawings, Figure 13 , Figure 14As shown, the edge of the universal ball disc 81 and the end plate 10 are uniformly provided with a plurality of second threaded holes 103, which are threadedly connected with fixing bolts. The center of the end plate 10 is provided with a circular through hole 101 and a hexagonal cavity 102, wherein the hexagonal cavity 102 is arranged to face away from the flange plate, the head of the flange bolt 12 is arranged in the hexagonal cavity 102, the rod of the flange bolt 12 passes through the circular through hole 101, the reserved hole 11, the circular hole of the gusset plate, and is threadedly connected with the nut 13 on the top surface or the bottom surface of the I-beam flange plate, the end plate 10 is connected to the inner side of the flange plate by tightening the nut 13, and then the universal ball disc 81 is connected to the inner side of the end plate 10.

[0047] It can be understood that, in the process of the transverse face-out bending moment loading, the I-beam test piece 1 will be correspondingly transversely bent and deformed, causing the upper flange plate and the lower flange plate to be inclined, the ear rings 71 at both ends of the inner pulling jack 7 and the inner pulling connector 9, and the universal ball discs 81 at both ends of the outer pushing jack 8 and the end plate 10, can all be rotationally connected, since the adjusting platform is capable of real-time self-adaptive adjustment of the transverse posture of the I-beam test piece, so as to ensure that the force exerted by the jacks always remains vertical.

[0048] In the embodiment, four face-out loading devices are uniformly arranged along the axial direction of the I-beam test piece 1, all the inner pulling jacks 7 and the outer pushing jacks 8 are driven by the same oil pump, the outlet of the oil pump is divided into two independently controlled oil paths, each of which is provided with an electromagnetic valve and a proportional pressure reducing valve, the electromagnetic valve controls the stroke direction of the jack, and the proportional pressure reducing valve always locks the oil pressure ratio as P1:P2=S2:S1 according to the piston area ratio (S1:S2) of the jack when it is outward pushed or inward pulled, so as to ensure that the output of the inner pulling jack 7 and the outer pushing jack 8 is equal; the two oil paths are then divided into four by the oil distribution block, so as to synchronously drive the four inner pulling jacks and the four outer pushing jacks. The backflow oil after work is converged into one by the oil distribution block, and is returned to the oil pump through the electromagnetic valve, so as to form a closed loop oil path.

[0049] Embodiment 2 The loading method of the composite loading device capable of correcting the posture of the I-beam disclosed in the embodiment uses the composite loading device capable of correcting the posture of the I-beam disclosed in the embodiment 1, and the specific steps are as follows: Symmetrical and equidistant reserved holes are reserved when the I-beam test piece 1 is manufactured, and an inclinometer is installed; A buffer air bag is arranged on the hinged support and fixed to the adjusting platform, the two ends of the I-beam test piece 1 are arranged on the adjusting platform, the hinged support is locked by a temporary support rod during installation, the inclinometer and the adjusting platform are connected, the adjusting platform adjusts the transverse posture of the I-beam test piece 1 and is locked; The face-out loading device and the longitudinal loading device are sequentially assembled, and the temporary support rod is removed, and the loading is started; When loading, the I-beam test piece 1 can be subjected to longitudinal in-plane bending shear and transverse out-of-plane bending moment loading simultaneously, or single-mode loading can be performed first and then composite loading; for example, the I-beam test piece 1 is subjected to longitudinal in-plane bending shear loading by the actuator until the web oblique crack appears, then the out-of-plane loading device is started to apply a constant transverse bending moment to the web, and then longitudinal in-plane bending shear is continued until the test piece is destroyed. When composite loading, the platform 4 adjusts the transverse posture of the I-beam test piece 1 in real time according to the detection results of the two inclinometers, avoids the transverse deviation of the vertical loading ball seat during composite loading, and further avoids the generation of additional torque to interfere with the test results.

[0050] In the embodiment, the longitudinal in-plane bending shear loading applies a vertical force Fn to the loading ball seat in the middle of the I-beam test piece 1 by the actuator, and force or displacement control is used, generally force control at the beginning of loading and displacement control near the destruction; the transverse out-of-plane bending moment loading uses the out-of-plane loading device and force control, the size of the jack output is changed by adjusting the oil pump oil pressure, the pump outlet is divided into two independent oil paths and the oil pressure ratio (P1:P2=S2:S1) is locked to ensure that the inner pulling jack and the outer pushing jack apply forces of equal size and opposite direction.

[0051] In the embodiment, when assembling the out-of-plane loading device, the jacks are installed on the inner side of the I-beam test piece 1 in the order of top first and bottom last; for example, the flange bolt 12 is first installed at the reserved hole 11 on the top surface of the I-beam test piece 1, then the flange bolt 12 is connected with the inner pulling connector 9 or the end plate 10, and then the inner pulling connector 9 or the end plate 10 is connected with the top end of the inner pulling jack 7 or the outer pushing jack 8.

[0052] After all the jacks are suspended and installed on the inner side of the flange plate of the I-beam test piece 1, the jacks are extended by pre-pressurizing the oil pump and controlling the jacks by the electromagnetic valve, and the lower connection is completed in sequence. After all the jacks are connected in place, the jacks are bidirectionally and reciprocally depressurized by the electromagnetic valve.

[0053] Although the specific embodiments of the present application have been described above with reference to the drawings, it is not a limitation on the scope of protection of the present application, and those skilled in the art should understand that various modifications or variations made by those skilled in the art without creative labor on the basis of the technical solutions of the present application are still within the scope of protection of the present application.

Claims

1. A composite loading device for correcting the attitude of an I-beam, characterized in that, The face-out loading device comprises bidirectional jacks on both sides of the web of the I-beam specimen, which are respectively inner pulling jacks and outer pushing jacks, and the end of the jack is connected with the upper flange plate or the lower flange plate of the I-beam specimen; the inner pulling jacks and the outer pushing jacks apply forces of equal magnitude but opposite directions; the axial spacing L of the jack is consistent with the transverse spacing T. The longitudinal loading device comprises a loading ball seat at the center of the top surface of the I-beam specimen, and the top surface of the loading ball seat is connected with an actuator perpendicular to the I-beam specimen. One end of the I-beam specimen is arranged on a fixed hinge support, and the other end is arranged on a sliding hinge support; a regulating platform is arranged between the hinge support and the I-beam specimen, and the axis of the regulating platform is parallel to the axis of the I-beam specimen. The regulating platform comprises a slidingly connected arc-shaped base and a swing platform, the bottom surface of the swing platform is provided with an arc-shaped groove, the top surface of the arc-shaped groove is provided with a worm gear groove, the arc-shaped base is rotationally connected with a worm inside, the worm is engaged with the worm gear groove, a stepping motor is installed on the side surface of the arc-shaped base, and the output shaft of the stepping motor is fixedly connected with the worm.

2. The composite loading device for correcting the attitude of an I-beam according to claim 1, wherein The upper flange plate and the lower flange plate are both provided with an inclinometer; a PLC controller is further installed on the arc-shaped base, the inclinometer is connected with the communication interface of the PLC controller, and the PLC controller is electrically connected with the stepping motor.

3. The composite loading device for correcting the attitude of an I-beam according to claim 2, wherein The fixed hinge support or the sliding hinge support both comprises a base, a roller is placed on the base, and a top plate is fixedly connected with the roller; a limiting strip is placed on both sides of the roller of the fixed hinge support and is fixedly connected with the base, and no limiting strip is arranged on both sides of the roller of the sliding hinge support; the regulating platform is fixedly connected with the top plate, and the two sides of the regulating platform are provided with buffer air bags.

4. The combined loading device for correcting the attitude of an I-beam according to claim 2, wherein Temporary support rods are further arranged on the axial side surface of the fixed hinge support or the sliding hinge support, the top end of the temporary support rod is bolted with the top plate, and the bottom end is bolted with the base, so as to limit the rotation of the fixed hinge support or the sliding hinge support.

5. The combined loading device for correcting the attitude of an I-beam according to claim 4, wherein The edge position of the upper flange plate and the lower flange plate is provided with a position corresponding reserved hole, the inner pulling jack is fixedly connected with an ear ring at both ends, and the outer pushing jack is fixedly connected with a universal ball disc at both ends; the ear ring or the universal ball disc is connected with the reserved hole through an inner pulling connecting piece or an end plate.

6. The combined loading device for correcting the attitude of an I-beam according to claim 1, wherein The inner pulling connecting piece comprises a U-shaped fork and a pin, a pin hole matched with the ear ring is formed in the U-shaped fork, the ear ring is inserted into the U-shaped fork in alignment and then the pin is inserted, a first threaded hole is formed in the end of the U-shaped fork away from the ear ring, and the first threaded hole is threadedly connected with the flange bolt in the reserved hole.

7. The combined loading device for correcting the attitude of an I-beam according to claim 6, wherein The universal ball disc and the end plate are uniformly provided with a plurality of second threaded holes, the second threaded holes are threadedly connected with fixed bolts, a circular through hole and a hexagonal cavity are formed in the center of the end plate, the head of the flange bolt is left in the hexagonal cavity, the rod of the flange bolt passes through the circular through hole, the reserved hole and a pad hole, and is threadedly connected with a nut on the top surface or the bottom surface of the I-beam flange plate.

8. The combined loading device for correcting the attitude of an I-beam according to claim 6, wherein The specific steps are as follows:

9. The loading method of the composite loading device for the attitude of the I-beam according to any one of claims 1-8, characterized in that, During the production of the I-beam specimen, the symmetric and equidistant reserved holes are reserved, and the inclinometer is installed. ​ The buffer air bag is arranged on the hinge support and fixed to the adjusting platform, the two ends of the I-beam test piece are erected on the adjusting platform, and the hinge support is locked by the temporary support rod during installation; the inclinometers are connected to the adjusting platform, the adjusting platform adjusts the posture of the I-beam test piece and is locked; The out-of-plane loading device and the longitudinal loading device are assembled in sequence; the temporary support rod is removed to start loading; During loading, the I-beam test piece can be subjected to longitudinal in-plane bending shear and transverse out-of-plane bending moment loading simultaneously, or single-mode loading can be performed first, and then composite loading can be performed. During composite loading, the adjusting platform adjusts the transverse posture of the I-beam test piece in real time according to the detection results of the two inclinometers; the loading data when the web oblique crack appears and when the I-beam test piece is destroyed are recorded.

10. The loading method of the composite loading device for the attitude of the I-beam according to claim 9, characterized in that, The longitudinal loading device adopts force control at the initial stage of loading and displacement control when the I-beam test piece is close to destruction; the out-of-plane loading device adopts force control.

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