Mechanical recording device for deformation process of buckling restrained brace

Abstract

The invention discloses a mechanical recording device for the deformation process of a buckling restrained brace. The mechanical recording device comprises a restraining sleeve of a supporting core material 1, a metal foil reel, an elastic ruler needle, a ball screw assembly and a miniature rotating ratchet wheel, according to the recording device, relative deformation between the core material and the constraint sleeve is recorded through sliding recording of the elastic ruler needle on the metal foil. In order to ensure that the stretching motion of the metal foil piece along with the rotation of the screw rod always faces a certain fixed direction, a micro rotating ratchet wheel is arranged in the screw rod, and when the supporting deformation speed and direction are changed, the sliding recording position of the elastic ruler needle on the metal foil piece is correspondingly changed, so that the deformation history of the supporting core material is completely presented; and an accurate basis is provided for accurately quantifying accumulated plastic deformation of the core material and evaluating the residual low-cycle fatigue life of the core material. The device does not need external energy supply and does not need daily maintenance and overhaul, so that the device has extremely high reliability in a strong earthquake.

Description

Technical Field

[0001] The invention relates to the field of engineering test recording devices of construction engineering technology, and in particular to a mechanical recording device for the deformation history of a buckling restrained support. Background Art

[0002] Metal materials, represented by steel, are the main materials for ductile yielding components in current structural design. By making such components yield at a preset deformation level, the lateral stiffness of the building structure system can be reduced and the equivalent period can be extended, thereby reducing the equivalent force of the structure under a strong earthquake and making the seismic design results of the structure more economical. Furthermore, under the premise of reasonable design, the yielding components or parts of the structure are limited to the preset positions, so that such yielding components can be quickly replaced after a strong earthquake, greatly improving the seismic toughness of the structure.

[0003] However, when metal yielding components undergo reciprocating plastic deformation, there is a problem of ductile fracture caused by accumulated plastic damage. Since component fracture will greatly weaken the seismic resistance of the structure, ensuring that metal yielding components have sufficient cumulative plastic deformation capacity is an important part of the seismic design of such components and their structures.

[0004] The cumulative plastic deformation capacity of metal components is not only closely related to material properties, structural details, stress state, etc., but also significantly affected by its deformation history. Since building structures may experience multiple earthquakes of varying magnitudes during their service life, quantifying the residual plastic deformation capacity of metal energy dissipation and shock absorbing components and judging whether they need to be replaced on this basis is an important part of ensuring the seismic safety of the structure.

[0005] The residual deformation capacity of a metal component can be obtained by subtracting its known plastic deformation history (consumption) from its cumulative plastic deformation capacity (total amount), and then judging whether the component can meet the subsequent service function requirements, that is, whether it needs to be replaced. In this process, it is particularly critical to accurately record the deformation history of such components (especially the deformation history of large strain amplitude).

[0006] The deformation history of components can certainly be recorded with the help of various electronic or electromagnetic equipment, but such equipment requires continuous energy supply and regular maintenance. Since the building energy supply system may stop in a strong earthquake, for metal energy dissipation and shock absorption components that are mainly used to resist strong earthquakes, many existing equipment that requires external energy supply is difficult to meet the requirements for recording their deformation history. Therefore, it is necessary to develop mechanical component deformation history recording equipment that does not rely on external energy, does not require regular maintenance, and has high reliability. Summary of the invention

[0007] Purpose of the invention: In order to solve the problems existing in the prior art, the present invention provides a mechanical recording device for the deformation history of a buckling-restrained support, which does not require external power supply and daily maintenance and overhaul, and has extremely high reliability under strong earthquakes.

[0008] Technical solution: To achieve the above-mentioned purpose, the present invention can adopt the following technical solution: a mechanical recording device for the deformation history of a buckling restrained support, comprising:

[0009] A supporting core material having a cross-shaped axial cross section and including a first core material end and a second core material end;

[0010] A restraining sleeve is circumferentially sleeved on the outside of the supporting core material, and the first core material end and the second core material end are exposed outside the restraining sleeve;

[0011] The metal foil reel is arranged near the end of the first core material, and comprises a metal foil arranged above the constraint sleeve in a tensioned state, and two rotating shafts respectively fixed to both sides of the constraint sleeve for the metal foil to be movably wound; there is no axial relative displacement between the metal foil and the constraint sleeve;

[0012] An elastic ruler needle, one end of which is connected to the end of the first core material and the other end of which is in contact with the metal foil, so as to realize sliding recording of relative deformation between the supporting core material and the restraining sleeve;

[0013] The ball screw assembly comprises a ball screw and a screw nut, wherein the screw nut is connected to an elastic ruler needle and the two maintain the same axial displacement; the ball screw rotates under the displacement drive of the screw nut;

[0014] A miniature rotating ratchet is connected to the ball screw on one side and to the metal foil reel on the other side, so as to limit the direction in which the ball screw drives the metal foil reel to rotate.

[0015] Furthermore, the gap between the supporting core material and the constraining sleeve is filled with non-bonding isolation material.

[0016] Furthermore, the two rotating shafts are symmetrically fixed on the two sides of the sleeve through positioning supports on both sides. The rotating shaft close to the micro-rotating ratchet side is the foil roll that has completed displacement burning, and the rotating shaft on the opposite side is used to store the metal foil that has not yet been displacement burned.

[0017] Furthermore, the elastic ruler needle is arranged parallel to the core material axis, and includes a connecting section and a ruler needle section, wherein the connecting section is fixedly connected to the end of the first core material; the ruler needle section is in the shape of a slender needle, including a conical needle tip and a ruler section.

[0018] Furthermore, the end surface of the connecting section near the end of the first core material extends downward and outward to expand into an inverted "U" shape, connected to the cross portion on the cross end of the first core material end, and its axial displacement is consistent with that of the first core material end.

[0019] Furthermore, the ruler segment is an axially extending slender rod with a conical needle tip at the end, and the tip of the conical needle tip points to and contacts the surface of the metal foil; when the end of the first core material undergoes axial displacement, the conical needle tip leaves a scratch on the surface of the metal foil, thereby achieving sliding recording of relative deformation between the end of the first core material and the sleeve.

[0020] Furthermore, one end of the ball screw near the metal foil reel is connected to the micro-rotating ratchet, and the other end passes through a horizontal U-shaped groove fixedly connected to the end of the first core material, and the opening of the horizontal U-shaped groove is fixedly connected to the cross part of the cross end by bolts; the middle section of the ball screw is engraved with threads, and the balls inside the threads are in contact with the inner wall of the screw nut; the design of the ball screw converts linear motion into rotational motion. Driven by the elastic ruler needle, the screw nut moves along the axial direction of the ball screw, driving the balls between the threads and the inner wall of the nut to roll; during the movement of the balls, the rolling friction force generated will cause the ball screw to rotate around its own axis, and drive the micro-rotating ratchet connected to the end to rotate together.

[0021] Furthermore, the screw nut is linked with the elastic ruler needle through a displacement synchronization part, and the axial displacement is consistent; the displacement synchronization part is an inclined strip body, and both ends are respectively connected to the elastic ruler needle and the screw nut by bolts.

[0022] Furthermore, the micro-rotating pawl includes a pawl and a ratchet, the pawl is fixedly connected to the ball screw, and the ratchet is connected to the metal foil reel. The movement of the screw nut drives the ball screw to rotate, and when the ball screw rotates clockwise around the axis, the ratchet is locked, and the pawl is inserted into the ratchet tooth groove to rotate it, and then the ball screw drives the metal foil to wind and stretch; when the ball screw rotates counterclockwise around the axis, the pawl can slide over the ratchet tooth back, so that the ratchet is loosened, thereby stopping the ball screw from driving the metal foil to wind.

[0023] Furthermore, there is no axial relative displacement between the constraint sleeve and the end of the second core material, and the relative displacement between the elastic ruler and the constraint sleeve is the total deformation of the core material.

[0024] Beneficial effects: The present invention has the following advantages: (1) The present invention can accurately record the deformation history of ductile energy dissipation and shock absorbing components, while ensuring the reliability of the device under strong earthquakes. (2) The device of the present invention fully presents the deformation history of the supporting core material, thereby providing an accurate basis for accurately quantifying the accumulated plastic deformation of the core material and evaluating its remaining low-cycle fatigue life. (3) The device of the present invention does not require external power supply and daily maintenance and inspection, which not only reduces maintenance costs, but also ensures that the device has extremely high reliability under strong earthquakes. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 1 is a schematic diagram of the overall structure of the mechanical recording device for buckling restraint support deformation history in Example 1 of the present invention;

[0026] Figure 2 is a schematic diagram of the connection structure between the elastic ruler needle and the supporting core material in Example 1 of the present invention;

[0027] Figure 3 is an axonometric view and a top view of the metal foil reel and the restraining sleeve in Example 1 of the present invention;

[0028] Figure 4 It is a schematic diagram of the structure after the elastic ruler needle, the metal foil reel, the restraining sleeve and the supporting core material are assembled and installed in the embodiment 1 of the present invention;

[0029] Figure 5 Schematic diagram of the structure of the connection between the elastic ruler needle and the screw nut in Example 1 of the present invention

[0030] Figure 6 1 is a schematic diagram of the structure of the ball screw-micro rotating ratchet-metal foil reel in Example 1 of the present invention;

[0031] Figure 7 It is a schematic diagram of the structure of the micro rotating ratchet in Example 1 of the present invention. DETAILED DESCRIPTION

[0032] In order to make the technical features and effects achieved by the present invention easy to understand, the following embodiments further explain in detail the structure and use principle of the mechanical recording device for the deformation history of the buckling restrained support of the present invention in conjunction with the accompanying drawings.

[0033] Example 1

[0034] See also Figure 1-2 As shown, the present invention discloses a mechanical recording device for buckling restraint support deformation history, comprising: a support core material 1, a restraint sleeve 2, a metal foil reel 3, an elastic ruler needle 4, a ball screw assembly and a micro-rotating ratchet 7;

[0035] The axial cross section of the supporting core material 1 is a cross shape, including a core material body 11 and a first core material end 12 and a second core material end 13 at both ends; the restraining sleeve 2 is circumferentially sleeved on the outside of the core material body 11 of the supporting core material 1, and the first core material end 12 and the second core material end 13 are exposed outside the restraining sleeve 2; the gap between the supporting core material 1 and the restraining sleeve 2 is filled with a non-bonded isolation material 8, which can be specifically referred to Figure 2 shown.

[0036] Please refer to Figure 3 As shown, the metal foil reel 3 is arranged near the first core material end 12, including a metal foil 33 arranged above the constraint sleeve in a tensioned state, and two rotating shafts 31 fixed on both sides of the constraint sleeve for the metal foil 33 to be movably wound; there is no axial relative displacement between the metal foil 33 and the constraint sleeve 2; the two rotating shafts 31 are symmetrically fixed on the two sides of the constraint sleeve 2 through the positioning supports 32 on both sides; the rotating shaft close to the micro-rotating ratchet 7 side is a foil roll that has completed displacement burning, and the opposite side rotating shaft 31 is used to store the metal foil 33 that has not yet been displacement burned.

[0037] Please refer to Figure 2 As shown, one end of the elastic ruler needle 4 is connected to the first core material end 12, and the other end is in contact with the metal foil 33, so as to realize the sliding recording of the relative deformation between the supporting core material 1 and the constraining sleeve 2; specifically, the elastic ruler needle 4 is arranged parallel to the core material axis, and comprises a connecting section 42 and a ruler needle section 41, and the connecting section 42 is fixedly connected to the first core material end 12; specifically, the end surface of the connecting section 42 close to the first core material end 12 extends downward and expands into an inverted "U" shape, and is connected to the cross portion on the cross end of the first core material end 12, and its axial displacement is consistent with that of the first core material end 12.

[0038] The ruler needle section 41 is in the shape of a slender needle, and includes a ruler section 411 and a conical needle tip 412. The ruler section 411 is an axially extending slender rod, and the end is a conical needle tip 412, the tip of which points to the surface of the metal foil 33 and contacts it; when the first core material end 12 is axially displaced, the conical needle tip 412 leaves scratches on the surface of the metal foil 33, realizing the sliding recording of relative deformation between the first core material end 12 and the constraint sleeve 2.

[0039] The elastic ruler needle 4, the metal foil reel 3, the restraining sleeve 2 and the supporting core material 2 are assembled and installed as follows: Figure 4As shown. The gap between the supporting core material 2 and the restraining sleeve 4 is filled with non-bonded insulating material 8. The working principle of the combination is as follows: the elastic ruler needle 4 can move axially with the deformation of the supporting core material 1, and slide and record on the metal foil 3, thereby recording the relative deformation between the buckling restraining supporting core material 1 and the restraining sleeve 2. There is no axial relative displacement between the restraining sleeve 2 and the second core material end 13, and the relative displacement between the elastic ruler needle 4 and the restraining sleeve 2 is the total deformation of the core material.

[0040] Please refer to Figure 5 As shown, the ball screw assembly includes a ball screw 5 and a screw nut 6, the screw nut 6 is connected to the elastic ruler needle 4, and the two maintain the same axial displacement; specifically, the screw nut 6 is linked with the elastic ruler needle 4 through a displacement synchronization part 9, and the axial displacement is consistent; the displacement synchronization part 9 is an inclined strip body, and the two ends are respectively connected to the elastic ruler needle 4 and the screw nut 6 by bolts. The ball screw 5 rotates under the displacement drive of the screw nut 6; the micro rotating ratchet 7 is connected to the ball screw 5 on one side and the metal foil reel 3 on the other side, which limits the direction in which the ball screw 5 drives the metal foil reel 3 to rotate.

[0041] Please combine Figure 1 and Figure 6 As shown, one end of the ball screw 5 close to the metal foil reel 3 is connected to the micro-rotating ratchet 7, and the other end passes through the horizontal U-shaped groove 10 fixedly connected to the first core material end 12, and the opening of the horizontal U-shaped groove 10 is fixedly connected to the cross part of the cross end side of the first core material end 12 by bolts; the middle section of the ball screw 5 is engraved with threads, and the balls inside the threads are in contact with the inner wall of the screw nut 6; the design of the ball screw 5 converts linear motion into rotational motion. Driven by the elastic ruler 4, the screw nut 6 moves axially along the ball screw 5, driving the balls between the threads and the inner wall of the nut to roll; during the ball movement, the rolling friction force generated will cause the ball screw 5 to rotate around its own axis, and drive the micro-rotating ratchet 7 connected to the end to rotate together.

[0042] Please refer to Figure 7 As shown, the micro-rotating pawl 7 includes a pawl 71 and a ratchet 72, wherein the pawl 71 is fixedly connected to the ball screw 5, and the ratchet 72 is connected to the metal foil reel 3. The movement of the screw nut 6 drives the ball screw 5 to rotate, and when the ball screw 5 rotates clockwise around the axis, the ratchet 72 is locked, and the pawl 71 is inserted into the tooth groove of the ratchet 72 to rotate it, thereby the ball screw 5 drives the metal foil 33 to wind and stretch; when the ball screw 5 rotates counterclockwise around the axis, the pawl 71 can slide over the back of the ratchet 72 teeth, so that the ratchet 72 is loosened, thereby stopping the ball screw 5 from driving the metal foil 33 to wind.

[0043] The mechanical recording device of the deformation history of the buckling restraint support of the present invention uses the sliding recording of the elastic ruler 4 on the metal foil 33 to record the relative deformation between the buckling restraint support core material 1 and the restraint sleeve 2. The elastic ruler 4 reciprocates along the support axis with the deformation of the core material, and at the same time drives the screw nut 6 connected to it to produce the same displacement history along the support axis. The reciprocating motion of the screw nut 6 drives the ball screw 5 to rotate. Without considering the micro-rotating ratchet 7, the clockwise and counterclockwise rotation of the screw will cause the metal foil 33 to rotate, so that the metal foil 33 moves in the orthogonal direction of the support axis.

[0044] In this process, the forward and backward movement of the elastic ruler needle 4 corresponds to the clockwise and counterclockwise directions of the rotation of the metal foil reel 3 around the axis. However, there are two problems with the above design: First, if the direction of the side shaft 31 of the screw nut 6 winding and stretching the metal foil 33 is regarded as the positive direction, when the metal foil reel 3 rotates forward, the side shaft 31 can drive the opposite side shaft 31 to rotate synchronously; but when the metal foil reel 3 rotates in the reverse direction, it is difficult for the two end shafts to achieve synchronous winding, which will cause the middle part of the metal foil 33 to loosen or no longer be tensioned, affecting the accurate recording of the displacement information. Second, when the reel rotates in the reverse direction, the metal foil 33 that has completed the displacement information recording will return to the top of the constraint sleeve 2 to record the displacement information, and the elastic ruler needle 4 may have multiple turns of reciprocating recording on the metal foil 33, causing the track to overlap, affecting the device's accurate capture of the complete deformation process of the support.

[0045] In order to solve the above two problems, the device is equipped with a micro-rotating ratchet 7 to ensure that the stretching movement of the metal foil 33 caused by the rotation of the ball screw 5 is always in a fixed direction. When the elastic ruler 4 moves forward, the ratchet 72 is locked, and the rotation of the ball screw 5 directly drives the metal foil 33 to wind and stretch, and the displacement information recorded is an oblique line; when the elastic ruler 4 moves backward, the ratchet 72 is loosened, and the rotation of the ball screw 5 no longer drives the metal foil 33 to wind, and the displacement information recorded is a vertical line. The setting of the micro-rotating ratchet 7 can ensure that when the direction of the support deformation speed changes, the sliding recording position of the elastic ruler 4 on the metal foil 33 will change accordingly, thereby fully presenting the deformation history of the support core material 1, and then providing an accurate basis for accurately quantifying the accumulated plastic deformation of the core material and evaluating its remaining low-cycle fatigue life. It also provides a scientific basis for judging whether its accumulated plastic deformation exceeds the safety threshold and whether the support core material needs to be replaced after the earthquake.

[0046] In addition, the device of the present invention does not require external energy supply and daily maintenance and overhaul, and can accurately record the deformation history of the ductile energy dissipation and shock absorbing components, while ensuring the reliability of the device under strong earthquakes.

Claims

1. A mechanical recording device for deformation history of buckling restrained support, characterized in that include: A supporting core material having a cross-shaped axial cross section and including a first core material end and a second core material end; A restraining sleeve is circumferentially sleeved on the outside of the supporting core material, and the first core material end and the second core material end are exposed outside the restraining sleeve; The metal foil reel is arranged near the end of the first core material, and comprises a metal foil arranged above the constraint sleeve in a tensioned state, and two rotating shafts respectively fixed to both sides of the constraint sleeve for the metal foil to be movably wound; there is no axial relative displacement between the metal foil and the constraint sleeve; An elastic ruler needle, one end of which is connected to the end of the first core material and the other end of which is in contact with the metal foil, so as to realize sliding recording of relative deformation between the supporting core material and the restraining sleeve; The ball screw assembly comprises a ball screw and a screw nut, wherein the screw nut is connected to an elastic ruler needle and the two maintain the same axial displacement; the ball screw rotates under the displacement drive of the screw nut; A miniature rotating ratchet is connected to the ball screw on one side and to the metal foil reel on the other side, so as to limit the direction in which the ball screw drives the metal foil reel to rotate.

2. The buckling restrained brace deformation history mechanical recording device according to claim 1, characterized in that: The gap between the supporting core material and the restraining sleeve is filled with non-bonding isolation material.

3. The buckling restrained brace deformation history mechanical recording device according to claim 1, characterized in that: The two rotating shafts are symmetrically fixed on the two sides of the sleeve through positioning brackets on both sides. The rotating shaft close to the micro-rotating ratchet wheel is the foil roll that has completed displacement burning, and the rotating shaft on the opposite side is used to store the metal foil that has not yet been displacement burned.

4. The buckling restrained brace deformation history mechanical recording device according to claim 1, characterized in that: The elastic ruler needle is arranged parallel to the core material axis, and comprises a connecting section and a ruler needle section, wherein the connecting section is fixedly connected to the end of the first core material; the ruler needle section is in the shape of an elongated needle, and comprises a tapered needle tip and a ruler section.

5. The buckling restrained brace deformation history mechanical recording device according to claim 4, characterized in that: The end surface of the connecting section near the end of the first core material extends downward and outward to expand into an inverted "U" shape, and is connected to the cross portion on the cross end of the first core material end, and its axial displacement is consistent with that of the first core material end.

6. The buckling restrained brace deformation history mechanical recording device according to claim 4, characterized in that: The ruler section is an axially extending slender rod with a conical needle tip at the end, the tip of which points to and contacts the surface of the metal foil. When the end of the first core material undergoes axial displacement, the conical needle tip leaves a scratch on the surface of the metal foil, thereby achieving sliding recording of relative deformation between the end of the first core material and the sleeve.

7. The buckling restrained brace deformation history mechanical recording device according to claim 1, characterized in that: One end of the ball screw close to the metal foil reel is connected to the micro-rotating ratchet, and the other end passes through a horizontal U-shaped groove fixedly connected to the end of the first core material. The opening of the horizontal U-shaped groove is fixedly connected to the cross part on the cross end side by bolts; the middle section of the ball screw is engraved with threads, and the balls inside the threads are in contact with the inner wall of the screw nut; the design of the ball screw converts linear motion into rotational motion.

8. The buckling restrained brace deformation history mechanical recording device according to claim 1 or 7, characterized in that: The screw nut is linked with the elastic ruler needle through a displacement synchronization part, and the axial displacement is consistent; the displacement synchronization part is an inclined strip body, and the two ends are respectively connected to the elastic ruler needle and the screw nut by bolts.

9. The buckling restrained brace deformation history mechanical recording device according to claim 1, characterized in that: The micro-rotating pawl comprises a pawl and a ratchet wheel, wherein the pawl is fixedly connected to the ball screw, and the ratchet wheel is connected to the metal foil reel.

10. The buckling restrained brace deformation history mechanical recording device according to claim 1, characterized in that: There is no axial relative displacement between the constraint sleeve and the end of the second core material, and the relative displacement between the elastic ruler needle and the constraint sleeve is the total deformation of the core material.

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