Inerter shock mitigation system with negative stiffness shape memory alloy

Abstract

The application relates to a negative stiffness shape memory alloy inertial damper system, which comprises an outer cylinder, an inertial unit, a negative stiffness unit and a shape memory alloy unit; the outer cylinder is externally closed to provide support and protection for the inside; the inertial unit is installed in the outer cylinder and comprises a screw rod, balls, a ball nut, a rotating mass and a through bolt; the negative stiffness unit is connected with the inertial unit, is installed in the outer cylinder and has a negative stiffness characteristic, and comprises a bolt, a pre-pressing spring, an inner spring connecting piece and an outer spring connecting piece; the shape memory alloy unit is connected with the inertial unit, is partially installed in the outer cylinder to form an inner shape memory alloy cable group and is partially installed outside the outer cylinder to form an outer shape memory alloy cable group, and each group comprises four shape memory alloy wires twisted into a cable. Through the combination of the outer cylinder, the inertial unit, the negative stiffness unit and the shape memory alloy unit, the deformation of the shape memory alloy is amplified, and the energy dissipation capacity of the damper system is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of structural energy dissipation, in particular to an inertial damper system with negative stiffness shape memory alloy. BACKGROUND

[0002] The common inertial damper system is mostly composed of inertial units, spring units and viscous damper units in series and parallel. In order to ensure the sealing of the viscous damper material during use, the processing precision is extremely high. On the other hand, the mechanical form of the existing inertial damper system increases the additional stiffness of the structure, changes the natural frequency of the structure, and leads to the decline of the damping performance.

[0003] The mechanical properties of shape memory alloy material make it have certain damping energy dissipation and self-resetting characteristics, but its energy dissipation capacity is relatively insufficient due to the limitation of the limit displacement and relative speed, which may lead to the adverse effect of peak response amplification of the structure under the action of earthquake. SUMMARY

[0004] Therefore, it is necessary to provide an inertial damper system with negative stiffness shape memory alloy to realize efficient absorption of energy and facilitate processing and installation.

[0005] The present application provides an inertial damper system with negative stiffness shape memory alloy, comprising:

[0006] an outer cylinder;

[0007] an inertial unit installed in the outer cylinder, comprising a lead screw, a ball, a ball nut, a rotating mass and a through bolt, the lead screw, the ball and the ball nut forming a ball screw to realize the conversion of the motion form, the rotating mass being fixedly connected to the ball nut through the through bolt, the ball nut driving the rotating mass to rotate around the lead screw;

[0008] a negative stiffness unit connected to the inertial unit and installed in the outer cylinder, having negative stiffness characteristics, comprising a bolt, a pre-press spring, an inner spring connecting piece and an outer spring connecting piece, the pre-press spring being arranged symmetrically around the lead screw, one end of the pre-press spring being hingedly connected to the lead screw through the inner spring connecting piece, and the other end of the pre-press spring being fixedly connected to the outer cylinder through the outer spring connecting piece and the bolt;

[0009] a shape memory alloy unit connected to the inertial unit, partially installed in the outer cylinder to form an inner shape memory alloy cable group, and partially installed outside the outer cylinder to form an outer shape memory alloy cable group, each group comprising four shape memory alloy wires twisted into a cable, the cable realizing energy dissipation and efficiency through the connection of the negative stiffness unit, the inertial unit and the shape memory alloy unit.

[0010] In one of the embodiments, the system further comprises a connecting unit arranged on both sides of the screw rod, including a first ear ring and a second ear ring.

[0011] In one of the embodiments, one end of the ball nut is a flange disc, and the flange has bolt holes; the ball nut is provided with an oil supply hole, and the center of the ball nut is a screw thread hole.

[0012] In one of the embodiments, the screw rod has a smooth outer surface at both ends, and the rest is a ball thread outer surface.

[0013] In one of the embodiments, a certain pre-pressing is applied to the ball screw to eliminate the gap between the screw rod and the ball.

[0014] In one of the embodiments, the spring inner connecting piece includes a center hole steel plate welded at the end of the screw rod, a first pin shaft, an inner linkage rod, and a spring inner connecting end plate; the spring outer connecting piece includes a screw rod, a second pin shaft, an outer linkage rod, and a spring outer connecting end plate; the pre-pressing spring is installed between the two end connecting pieces after the pre-pressing force between the spring inner connecting end plate and the spring outer connecting end plate reaches the expected level, and the pre-pressing length of the spring is calculated according to the required negative stiffness of the pre-pressing spring.

[0015] In one of the embodiments, the shape memory alloy unit further comprises a fastening nut.

[0016] In one of the embodiments, the outer cylinder includes a cavity, a rolling bearing, and an inner wall end plate; the cavity is provided with a center hole at one end; the outer ring of the rolling bearing is fixed to the inner wall of the cavity, and the inner ring is fixed to the outer side surface of the rotating mass; the inner wall end plate is welded to the inner wall of the cavity to provide support for the right end fastening nut of the inner shape memory alloy cable group.

[0017] In one of the embodiments, the rolling bearing includes an outer ring, an inner ring, steel balls, and a retainer, which are used to bear the radial and axial forces generated by the rotating mass.

[0018] In one of the embodiments, a single shape memory alloy cable of the shape memory alloy unit is twisted from seven shape memory alloy strands, and each shape memory alloy strand contains seven shape memory alloy wires.

[0019] The above-mentioned negative stiffness shape memory alloy inertial vibration absorption system improves the energy dissipation capacity of the shape memory alloy cable group through the magnification of the shape memory alloy deformation, fully utilizes the shape memory alloy cable group to provide self-resetting restoring force for the vibration absorption system, uses the conversion of the motion form in the inertial unit to convert the horizontal reciprocating motion of the structure into the rotational motion of the rotating mass through the ball screw pair, magnifies the inertial force of the rotating mass, realizes efficient absorption of energy, and improves the control of the vibration absorption system on the seismic response of the structure. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 A schematic diagram of an inertial-capacitive damping system with shape memory alloy having negative stiffness;

[0022] Figure 2 This is a front view of a ball bearing nut;

[0023] Figure 3 This is a schematic diagram of the flange disc at the end of a ball nut;

[0024] Figure 4 This is a schematic diagram of the internal connecting part of the spring;

[0025] Figure 5 This is a schematic diagram of the structure of the spring's outer connecting component;

[0026] Figure 6 This is a schematic diagram of the outer cylinder's structure;

[0027] Figure 7 This is a cross-sectional diagram of a single shape memory alloy cable.

[0028] Figure label:

[0029] 1. First earring; 15. Second earring; 2. Outer shape memory alloy cable assembly; 14. Inner shape memory alloy cable assembly; 3. Fastening nut; 4. Lead screw; 5. Ball bearing; 6. Ball bearing nut; 7. Rotating mass block; 8. Through bolt; 9. Outer cylinder; 10. Bolt; 11. Preloaded spring; 61. Flange disc; 62. Oil inlet; 63. Bolt hole; 64. Lead screw thread hole; 12. Spring inner connector; 121. Center-hole steel plate; 122. First pin; 123. Inner linkage rod; 124. Spring inner connecting end plate; 13. Spring outer connector; 131. Screw; 132. Second pin; 133. Outer linkage rod; 134. Spring outer connecting end plate; 91. Cavity; 92. Rolling bearing; 93. Inner wall end plate. Detailed Implementation

[0030] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely explain the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort should fall into the scope of the present application.

[0031] It should be noted that when a component is referred to as being "on" or "disposed on" another component, it can be directly on the other component or there can be intervening components. When a component is referred to as being "connected" to another component, it can be directly connected to the other component or there can be intervening components. The terms "vertical", "horizontal", "upper", "lower", "left", "right", and similar terms as used in the description of the present application are for the purpose of illustration only and do not indicate an exclusive orientation.

[0032] In addition, the terms "first", "second", and the like, do not denote any quantity or importance, but rather are used to distinguish one element from another, and are not intended to specify a particular order or sequence except where expressly so defined. Accordingly, these terms are used herein, and in the description of the application, merely to facilitate distinguishing one element from another, and are not meant to or do imply a specific order or sequence unless explicitly so defined.

[0033] In the present application, unless otherwise explicitly specified and limited, the "on", "under", "above", and "over" of a first feature to a second feature can mean that the first feature is in direct contact with the second feature, or the first feature is in indirect contact with the second feature through an intermediate medium. Moreover, the "above", "over", and "on" of a first feature to a second feature can mean that the first feature is directly above or obliquely above the second feature, or only means that the first feature is horizontally higher than the second feature. The "below", "under", and "underneath" of a first feature to a second feature can mean that the first feature is directly below or obliquely below the second feature, or only means that the first feature is horizontally lower than the second feature.

[0034] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as those commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the present application is for the purpose of describing a particular embodiment only and is not intended to be limiting of the present application. The use of the term "and / or" in the description of the present application includes all of the combinations of one or more relevant items.

[0035] The structural shock absorption technology mainly absorbs and consumes seismic energy through energy dissipation shock absorption elements to reduce the seismic response of the main structure, reduce the seismic damage of the main structure, and thus ensure the safety of the structure under the earthquake disaster and the recoverability of the structure function after the earthquake.

[0036] The inerter unit is a two-terminal acceleration-related element with mass amplification characteristics. By changing the motion mechanism, the apparent mass of the inerter unit can reach thousands of times of the actual mass. Due to the double-end nature of the inerter element, the inerter unit can be combined with other mechanical elements in various topological forms to form a shock absorption system that can achieve apparent mass amplification and energy dissipation. The most common inerter shock absorption system is formed by combining inerter units, spring units and viscous damper units in series and parallel forms. In order to ensure the sealing of the viscous damping material during use, the processing precision is extremely high. On the other hand, the mechanical form of the existing inerter shock absorption system increases the additional stiffness of the structure, changes the natural frequency of the structure, and reduces the shock absorption performance.

[0037] Shape memory alloy materials have shape memory effect that can restore to the original shape by heating after deformation under external force, and have superelasticity that can automatically recover after unloading when the environmental temperature is higher than a specific critical temperature of the material. The mechanical properties of shape memory alloy materials have certain damping energy dissipation and self-resetting characteristics, but the energy dissipation capacity is relatively insufficient due to the limitation of the limit displacement and relative speed, which may cause the undesirable effect of peak response amplification of the structure under the action of the earthquake.

[0038] The inerter shock absorption system with negative stiffness shape memory alloy of the present application will be described below. Figures 1-7 The inerter shock absorption system with negative stiffness shape memory alloy of the present application will be described below.

[0039] As shown in Figure 1 In one embodiment, the inerter shock absorption system with negative stiffness shape memory alloy includes:

[0040] The outer cylinder 9.

[0041] The inerter unit is installed in the outer cylinder 9 and includes a lead screw 4, a ball 5, a ball nut 6, a rotating mass 7 and a through bolt 8. The lead screw 4, the ball 5 and the ball nut 6 form a ball screw to realize the conversion of the motion form. The rotating mass 7 and the ball nut 6 are fixedly connected through the through bolt 8, and the ball nut 6 drives the rotating mass 7 to rotate around the lead screw 4.

[0042] The negative stiffness unit is connected with the inertial unit, is installed in the outer cylinder 9, has a negative stiffness characteristic, and comprises a bolt 10, a pre-press spring 11, a spring inner connecting piece 12 and a spring outer connecting piece 13; the pre-press spring 11 is arranged in axial symmetry with the lead screw 4, is hinged with the lead screw 4 at one end through the spring inner connecting piece 12, and is fixedly connected with the bolt 10 to the outer cylinder 9 at the other end through the spring outer connecting piece 13.

[0043] The shape memory alloy unit is connected with the inertial unit, is partially installed in the outer cylinder 9 to form an inner shape memory alloy cable group 14, and is partially installed outside the outer cylinder 9 to form an outer shape memory alloy cable group 2, each group comprising four shape memory alloy wires twisted into a cable, and the cable achieving energy dissipation and efficiency improvement through the connection of the negative stiffness unit, the inertial unit and the shape memory alloy unit.

[0044] Specifically, the lead screw 4 and the ball nut 6 of the inertial unit are filled with the ball 5 to form a ball screw, when the lead screw 4 moves horizontally, the ball 5 rolls between the lead screw 4 and the ball nut 6, and the horizontal movement of the lead screw 4 is converted into the rotary movement of the ball nut 6 with a small driving torque, the rotary mass block is fixedly connected with the ball nut 6 through the through bolt 8, the ball nut 6 drives the rotary mass block 7 to rotate around the lead screw 4, the rotary movement of the rotary mass block 7 generates a centrifugal force, the ball screw provides an action force in the opposite direction of the horizontal movement acceleration direction of the lead screw 4, and the inertial mass amplification effect is realized; when the pre-press spring 11 arranged in axial symmetry with the lead screw 4 is in a balanced position, the action forces provided by the two pre-press springs 11 for the lead screw 4 are equal and opposite, and the resultant force is zero; when the lead screw 4 moves in the horizontal direction, the action forces provided by the two pre-press springs 11 for the lead screw 4 are zero in the direction perpendicular to the lead screw 4, the resultant force in the horizontal direction is consistent with the displacement direction of the lead screw 4, and the resultant force shows negative stiffness relative to the displacement of the lead screw 4; the shape memory alloy is stretched and deformed under the action of the earthquake to achieve energy dissipation and provide a self-resetting restoring force, the inner shape memory alloy cable group 14 and the outer shape memory alloy cable group 2 are pre-tensioned to generate a pre-tightening force, and the generation of the pre-tightening force amplifies the deformation of the shape memory alloy and improves the energy dissipation capacity of the shape memory alloy cable group.

[0045] The negative stiffness shape memory alloy inertial vibration absorption system of the embodiment sets the inertial unit as an energy absorption mechanism, converts the horizontal reciprocating motion of the structure into the rotational motion of the rotating mass 7 through the ball screw, amplifies the inertial force of the rotating mass, realizes the efficient absorption of energy, and improves the control of the vibration absorption system on the seismic response of the structure; the negative stiffness unit is composed of a pair of pre-pressing springs 11, when the screw 4 moves horizontally and reciprocally, the pre-pressing spring 11 deviates from the balance position, generates a resultant force consistent with the displacement direction of the screw 4, and the negative stiffness characteristic can weaken the additional stiffness caused by the shape memory alloy, and at the same time, the negative stiffness characteristic provides a certain self-resetting ability for the vibration absorption system, has the advantages of inertia amplification, damping energy dissipation, additional stiffness reduction, and self-resetting. The horizontal reciprocating motion of the screw 4 is used to connect the inertial unit and the negative stiffness unit in parallel and then connect the shape memory alloy unit in series, fully utilizes the shape memory alloy cable group to provide a self-resetting restoring force for the vibration absorption system, and the shape memory alloy unit is used to replace the traditional viscous damper and is combined with the inertial unit, so that the sealing problem is solved, and the durability of the vibration absorption system is improved.

[0046] As shown in Figure 1 , in one embodiment, a negative stiffness shape memory alloy inertial vibration absorption system includes a connecting unit, the connecting unit is arranged on both sides of the screw 4, and includes a first ear ring 1 and a second ear ring 15.

[0047] Specifically, the first ear ring 1 is used to connect the shape memory alloy unit and the structure, and the second ear ring 15 is connected to the outer wall of the outer cylinder 9 through the bolt 10 and is used to connect the outer cylinder 9 and the structure.

[0048] In the embodiment, the outer cylinder 9 and the structure are connected through the first ear ring 1 and the second ear ring 15, which greatly facilitates processing and installation, and damaged components can be replaced after use, functional recovery is realized, and good engineering application and popularization value are achieved.

[0049] As shown in Figure 1 , Figure 2 , Figure 3 , in one embodiment, a negative stiffness shape memory alloy inertial vibration absorption system, the ball nut 6 has a flange disc 61 at one end, and the flange has a bolt hole 63; the ball nut is provided with an oil supply hole 62, and the center of the ball nut is a screw thread hole 64.

[0050] Specifically, the through bolt 8 fastens the ball nut 6 and the rotating mass 7 through the bolt hole 63, the oil supply hole 62 is suitable for oiling and lubrication during installation and use, and the screw thread hole 64 fastens the ball nut and the screw; the ball nut 6 adopts an end cover type ball circulation mode, the ball 5 is scooped from the screw thread of the screw shaft into the through hole of the ball nut 6 by the end cover, and then returns to the screw thread to move reciprocally.

[0051] In this embodiment, the ball nut 6 is used to firmly fix the rotating mass 7, avoiding the accidental falling of the elements, and the ball 5 is picked up from the thread of the screw shaft into the through hole of the ball nut 6. The ball nut 6 can be lubricated through the oil hole 62, facilitating maintenance and long-term use.

[0052] As shown in the drawings, Figure 1 In one embodiment, a negative stiffness shape memory alloy inertial vibration damping system is provided, in which the screw shaft 4 has a smooth outer surface at both ends and a ball thread outer surface at the remaining part.

[0053] Specifically, the smaller the lead of the ball thread, the greater the inertial mass amplification factor. However, too small lead will cause greater friction between the ball 5, the screw shaft 4 and the ball nut 6, resulting in the damping of the vibration damping system design unable to effectively play. Therefore, the lead of the ball thread is determined according to the required inertial mass amplification factor and the friction limit value.

[0054] In this embodiment, the lead size of the ball thread is used to control the inertial amplification factor, meeting the requirements of multiple scenarios and having high promotion value.

[0055] As shown in the drawings, Figure 1 In one embodiment, a negative stiffness shape memory alloy inertial vibration damping system is provided, in which a certain pre-pressing force is applied to the ball screw to eliminate the gap between the screw shaft 4 and the ball 5.

[0056] Optionally, the precision grade of the ball screw is C1, and the ball thread length of the screw shaft 4 is 800mm to meet the displacement limit requirement. In this embodiment, the gap between the screw shaft 4 and the ball 5 is eliminated to increase the stability of the system.

[0057] As shown in the drawings, Figure 4 , Figure 5 In one embodiment, a negative stiffness shape memory alloy inertial vibration damping system is provided, in which the spring inner connecting piece 12 includes a center hole steel plate 121 welded at the end of the screw shaft, a first pin shaft 122, an inner linkage rod 123 and a spring inner connecting end plate 124; the spring outer connecting piece 13 includes a screw rod 131, a second pin shaft 132, an outer linkage rod 133 and a spring outer connecting end plate 134; the pre-pressing spring 11 is installed between the two end connecting pieces after the pre-pressing force between the spring inner connecting end plate 124 and the spring outer connecting end plate 134 reaches the expected level, and the pre-pressing length of the spring is calculated according to the required negative stiffness of the pre-pressing spring 11.

[0058] Specifically, when the screw rod 4 moves horizontally, the pre-pressing spring 11 is deformed by the oblique tension, and the two springs generate a resultant force in the same direction as the movement direction of the screw rod 4, thereby showing a negative stiffness characteristic. The pre-pressing spring 11 is installed between the two end connectors after the pre-pressing force between the spring inner connecting end plate 124 and the spring outer connecting end plate 134 reaches the expected level. The pre-pressing length of the spring is calculated according to the required negative stiffness of the pre-pressing spring.

[0059] As shown in the drawings, Figure 1 In one embodiment, a negative stiffness shape memory alloy inertial damper system, the shape memory alloy unit further comprises a fastening nut 3.

[0060] Specifically, the inner shape memory alloy cable group 14 and the outer shape memory alloy cable group 2 are pre-tensioned to generate a pre-tightening force. After the expected pre-tightening force level is reached, the outer shape memory alloy cable group 2 is anchored at the end plate of the first ear ring 1 and one end of the screw rod 4 through the fastening nut 3 at both ends, and the inner shape memory alloy cable group 14 is anchored at the right end of the screw rod and the outer cylinder through the fastening nut 3 at both ends. When the screw rod 4 moves horizontally, the outer shape memory alloy cable group 2 and the inner shape memory alloy cable group 14 are stretched respectively, and the stretching deformation of the shape memory alloy cable group realizes energy dissipation and provides a self-resetting restoring force.

[0061] In this embodiment, the inner shape memory alloy cable group 14 and the outer shape memory alloy cable group 2 are fastened to the specified position through the fastening nut 3, which increases the safety and stability and makes the system easy to disassemble and replace parts, facilitating subsequent maintenance.

[0062] As shown in the drawings, Figure 6 In one embodiment, a negative stiffness shape memory alloy inertial damper system, the outer cylinder 9 comprises a cavity 91, a rolling bearing 92 and an inner wall end plate 93; the cavity 91 has a central hole at one end; the outer ring of the rolling bearing 92 is fixed to the inner wall of the cavity 9, and the inner ring is fixed to the outer side of the rotating mass 7; the inner wall end plate is welded to the inner wall of the cavity 9 to provide support for the right end fastening nut 3 of the inner shape memory alloy cable group 14. The rolling bearing 92 comprises an outer ring, an inner ring, steel balls and a retainer, which is used to bear the radial and axial forces generated by the rotating mass 7.

[0063] Specifically, the hole diameter of the central hole at the left end of the cavity 91 matches the diameter of the screw rod 4, and the screw rod 4 moves horizontally in and out of the cavity 91 through the central hole; the rolling bearing 92 can be a dustproof sealed deep groove ball bearing, and the dustproof sealing cover is made of steel plate stamping to prevent dust from entering the bearing raceway; the inner shape memory alloy cable group 14 is fixed to the inner wall end plate 93 through the fastening nut 3.

[0064] In this embodiment, the cavity 91 is used to provide safety protection for the internal elements, and the rolling bearing 92 and the inner wall end plate 93 are provided to support the elements.

[0065] like Figure 7 As shown, in one embodiment, an inertial capacitance damping system with negative stiffness shape memory alloy is provided. Each shape memory alloy cable of the shape memory alloy unit is formed by twisting together seven strands of shape memory alloy wire, with each strand containing seven shape memory alloy filaments. Optionally, the shape memory alloy cable is processed using Ti-50.8%Ni shape memory alloy filaments with a diameter of 2.0 mm.

[0066] In this embodiment, the shape memory alloy material used has a shape memory effect that allows it to recover its original shape after being deformed under external force by heating. Furthermore, when the ambient temperature is higher than a specific critical temperature of the material, it exhibits superelasticity, meaning that the deformation can automatically recover after unloading.

[0067] The aforementioned inertial-capacitive damping system with negative stiffness shape memory alloy reciprocates under seismic action, causing relative displacement between the first earring 1 and the second earring 15. The first earring 1 drives the outer shape memory alloy cable assembly 2 to extend and retract, while the second earring 15 drives the inner shape memory alloy cable assembly 14 to extend and retract via the outer cylinder 9. When the shape memory alloy is stretched, it generates energy dissipation and restoring force. The outer shape memory alloy cable assembly 2 and the inner shape memory alloy cable assembly 14 drive the lead screw 4 to perform horizontal reciprocating motion. The lead screw 4 drives the ball nut 6 to rotate via the ball bearing 5, and the ball nut 6 drives the rotating mass block 7 to rotate under the constraint of the rolling bearing 92. The rotating mass block 7 provides the lead screw 4 with an inertial force opposite to the direction of acceleration. The lead screw 4 drives the preload spring 11 to reciprocate on both sides of the equilibrium position via the inner spring connector 12 and the outer spring connector 13. When the preload spring 11 leaves the equilibrium position, it provides the lead screw 4 with a force in the same direction as the displacement.

[0068] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0069] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A capacitive damping system with negative stiffness shape memory alloy, characterized in that, include: outer cylinder; An inertial-capacitance unit is installed inside the outer cylinder; it includes a lead screw, balls, ball nuts, a rotating mass block, and through bolts; the lead screw, balls, and ball nuts form a ball screw to realize the conversion of motion mode; the rotating mass block and the ball nuts are fixedly connected by through bolts, and the ball nuts drive the rotating mass block to rotate around the lead screw; The negative stiffness unit, connected to the inertia-capacity unit, is installed inside the outer cylinder and has negative stiffness characteristics. It includes a bolt, a preload spring, an inner spring connector, and an outer spring connector. The preload spring is arranged symmetrically about the lead screw as the axis. One end is hinged to the lead screw through the inner spring connector, and the other end is fixed to the outer cylinder by the bolt through the outer spring connector. A shape memory alloy unit is connected to the inertia-capacity unit. Part of it is installed inside the outer cylinder to form an inner shape memory alloy cable group, and part of it is installed outside the outer cylinder to form an outer shape memory alloy cable group. Each group includes a cable made of four twisted shape memory alloy wires. The cable achieves energy efficiency through the connection of the negative stiffness unit, the inertia-capacity unit and the shape memory alloy unit.

2. The inertial-capacitive damping system with negative stiffness shape memory alloy according to claim 1, characterized in that, The system also includes a connection unit, which is disposed on both sides of the lead screw and includes a first earring and a second earring.

3. The inertial-capacitive damping system with negative stiffness shape memory alloy according to claim 1, characterized in that, One end of the ball nut is a flange disc with bolt holes; the ball nut is provided with an oil supply hole, and the center of the ball nut is a lead screw thread hole.

4. The inertial-capacitive damping system with negative stiffness shape memory alloy according to claim 1, characterized in that, The two ends of the lead screw are smooth circular outer surfaces, and the remaining part is a ball thread outer surface.

5. The inertial-capacitive damping system with negative stiffness shape memory alloy according to claim 1, characterized in that, A certain preload is applied to the ball screw to eliminate the gap between the screw and the balls.

6. The inertial-capacitive damping system with negative stiffness shape memory alloy according to claim 1, characterized in that, The inner spring connector includes a steel plate with a central opening welded to the lead screw end, a first pin, an inner linkage rod, and an inner spring connecting end plate; the outer spring connector includes a screw, a second pin, an outer linkage rod, and an outer spring connecting end plate; the preloaded spring is installed between the two end connectors after the preloaded force is applied between the inner and outer spring connecting end plates to reach the expected level, and the preloaded length of the spring is calculated according to the required negative stiffness of the preloaded spring.

7. The inertial-capacitive damping system with negative stiffness shape memory alloy according to claim 1, characterized in that, The shape memory alloy unit also includes a fastening nut.

8. The inertial-capacitive damping system with negative stiffness shape memory alloy according to claim 1, characterized in that, The outer cylinder includes a cavity, a rolling bearing, and an inner wall end plate; a central hole is opened at one end of the cavity; the outer ring of the rolling bearing is fixed to the inner wall of the cavity, and the inner ring is fixed to the outer side of the rotating mass block; the inner wall end plate is welded to the inner wall of the cavity to provide support for the right end fastening nut of the inner shape memory alloy cable assembly.

9. The inertial-capacitive damping system with negative stiffness shape memory alloy according to claim 8, characterized in that, The rolling bearing includes an outer ring, an inner ring, steel balls, and a cage, and is used to withstand radial and axial forces generated by the rotating mass.

10. The inertial-capacitive damping system with negative stiffness shape memory alloy according to claim 1, characterized in that, The shape memory alloy cable of the shape memory alloy unit is made of seven strands of shape memory alloy wires twisted together, and each strand of shape memory alloy wire contains seven shape memory alloy wires.

Images