Self-adaptive damping flexible spring based on shear thickening fluid-particle composite material

Abstract

The self-adaptive damping flexible spring based on the shear thickening liquid-particle composite material comprises an annular silica gel corrugated pipe 2, a cylindrical cavity is reserved in the middle of the annular structure of the silica gel corrugated pipe 2, and the cylindrical cavity extends in the length direction of the silica gel corrugated pipe 2; the bottom of the silica gel corrugated pipe 2 is connected with the base 1; the sleeve 5 is embedded in the top of the silica gel corrugated pipe 2; the silica gel corrugated pipe 2 comprises an inner pipe wall 21 and an outer pipe wall 22 which are coaxially arranged, a filler cavity is formed between the inner pipe wall 21 and the outer pipe wall 22, and the air tightness of the filler cavity is good; a cavity of the filler is filled with shear thickening liquid 10, spherical particles 3 and compressed air 8; according to the structure, the characteristics of the shear thickening fluid and the particle composite material are fully utilized, and a framework structure can be formed through particle stacking under static and low-frequency loads, so that good static bearing capacity is achieved; under impact and high-frequency load, the damping effects of vibration suppression and energy dissipation can be achieved through the shear thickening effect of the shear thickening fluid and friction among particles.

Description

Technical Field

[0001] The present invention belongs to the technical field of vibration isolation and shock resistance, and particularly relates to an adaptive damping flexible spring based on a shear thickening fluid-particle composite material. Background Art

[0002] Metal springs or elastic elements widely used in traditional mechanical systems can effectively provide elastic support, but their damping characteristics are weak, and it is difficult to quickly dissipate vibration energy under dynamic loads. To improve the shock resistance performance of the system, it is often necessary to additionally configure a damper, resulting in a complex structure, an increased volume, and it is difficult to achieve adaptive adjustment under low-frequency and high-frequency composite working conditions. Although damping technologies based on intelligent materials (such as magnetorheological fluids and electrorheological fluids) can achieve variable damping through external field regulation, they rely on external energy sources and precise control systems, and have problems such as low reliability, high cost, and response hysteresis. Shear thickening fluids have unique "shear thickening" characteristics and can quickly increase viscosity and dissipate energy at high strain rates, providing a new idea for passive damping design. However, a single STF material cannot form an effective support structure under static or quasi-static loads, and it is difficult to take into account the dual requirements of load bearing and damping, while particles can provide good static load-bearing capacity through stacking under static and quasi-static loads. Therefore, there is an urgent need for a new type of flexible elastic element that integrates load bearing, damping adaptability, and passive reliability, and synchronously solves the collaborative problem of load bearing and adaptive damping through the deep integration of material innovation and structural design.

[0003] A composite helical spring proposed in the patent with the publication number CN106438796A has a metal layer on the outer layer and a shear thickening glue on the inner layer. Although it can achieve a certain damping effect through the internal shear thickening gel, due to the outer metal layer, the helical spring cannot achieve effective shear thickening and fully dissipate energy when deformed under load.

[0004] The patent with the publication number CN116658557A involves a shear thickening fluid damper. Although it can dissipate and absorb energy by simultaneously using silicone oil and shear thickening fluid through structural design, its load-bearing capacity under static and quasi-static loads is insufficient. Summary of the Invention

[0005] In view of the above problems, the present invention proposes an adaptive damping flexible spring based on a shear thickening fluid-particle composite material. The idea is to combine a shear thickening fluid and particles and fill them into a silicone bellows. Under static and dynamic loads, it has both static load-bearing and dynamic energy dissipation, realizing a flexible spring with damping characteristics and overcoming the problem of weak damping characteristics of traditional metal springs.

[0006] An adaptive damping flexible spring based on a shear thickening fluid-particle composite material includes an annular silicone rubber bellows 2. A cylindrical cavity is left in the middle of the annular structure of the silicone rubber bellows 2, and the cylindrical cavity extends along the length direction of the silicone rubber bellows 2; the bottom of the silicone rubber bellows 2 is connected to a base 1, and a sleeve 5 is embedded at the top of the silicone rubber bellows 2.

[0007] The silicone rubber bellows 2 includes an inner pipe wall 21 and an outer pipe wall 22 arranged coaxially. A filler cavity is formed between the inner pipe wall 21 and the outer pipe wall 22, and the filler cavity has good airtightness; the filler cavity is filled with a shear thickening fluid 10, spherical particles 3 and compressed air 8.

[0008] More specifically, the longitudinal cross-sectional shape of the inner pipe wall 21 and the outer pipe wall 22 of the silicone rubber bellows 2 passing through the diameter of the silicone rubber bellows 2 is a corrugated line that periodically changes in the length direction of the silicone rubber bellows 2; the corrugated line of the inner pipe wall 21 is an inner corrugation, and the corrugated line of the outer pipe wall 22 is an outer corrugation; among them, the inner corrugation sine curve is R1 is the radius of the top of the inner pipe wall; the outer corrugation sine curve is R2 is the radius of the top of the outer pipe wall, where R2 - R1 = 10 mm, A is the amplitude of the inner corrugation and the outer corrugation, L is the length of the inner corrugation and the outer corrugation, L / N is the wavelength, and N is the number of corrugations with a whole period in the length direction of the silicone rubber bellows 2.

[0009] More specifically, a sealing ring 4 is provided at the joint between the bottom of the sleeve 5 and the silicone rubber bellows 2, and a gasket 9 is provided between the lower end of the sealing ring 4 and the outer pipe wall 22.

[0010] More specifically, the material of the spherical particles 3 is polyoxymethylene resin, and the density is 1.41 g / cm 3 , and the particle diameter is 4 - 8 mm.

[0011] More specifically, the thickness δ of the inner pipe wall and the outer pipe wall is 2 mm.

[0012] More specifically, a first annular groove that matches the bottom of the silicone rubber bellows 2 exists on the upper surface of the base 1, and the bottom of the silicone rubber bellows 2 is connected to the first annular groove.

[0013] More specifically, a second annular groove is provided at the top of the sleeve 5, a sealing gasket 6 is provided in the second annular groove, a top cover 7 that is embedded in the second annular groove and contacts the sealing gasket 6 is provided at the top of the sleeve 5, and the top cover 7 is fixedly connected to the sleeve 5 by glue.

[0014] More specifically, the material of the silicone rubber bellows 2 is a replica soft rubber compound, and its Shore hardness is 70; the materials of the base 1, the sleeve 5, the top cover 7 and the sealing gasket 6 are polylactic acid.

[0015] More specifically, the compressible gas 8 is nitrogen. The compressible gas 8 occupies 1 / 3 of the volume of the filler cavity.

[0016] The beneficial effects produced by the present invention include:

[0017] 1. The self-adaptive damping flexible spring of the present invention has a simple structure and is different from the weak damping characteristics of traditional metal springs. Through the filling of shear thickening fluid and particulate composite materials, a passive damping characteristic spring is realized, providing a new idea for the design of new springs and at the same time increasing the application range of shear thickening fluid.

[0018] 2. The flexible spring designed by the present invention makes full use of the characteristics of shear thickening fluid and particulate composite materials. Under static and low-frequency loads, it can form a skeleton structure through particle stacking to achieve good static load-bearing capacity; under impact and high-frequency loads, it can achieve damping effects of suppressing vibration and dissipating energy through the shear thickening effect of shear thickening fluid and friction between particles.

[0019] 3. The self-adaptive damping flexible spring based on shear thickening fluid - particulate composite material designed by the present invention can achieve different variable stiffness and damping characteristics by adjusting the shear thickening fluid and spherical particulate composite material; for example, by controlling influencing factors such as the mass fraction of shear thickening fluid and the diameter of spherical particles. In addition, the type of shear thickening fluid, the hardness, surface roughness and shape of particles can also be changed. Description of the Drawings

[0020] Figure 1 is the external structure diagram of the self-adaptive damping flexible spring based on shear thickening fluid - particulate composite material of the present invention.

[0021] Figure 2 is the internal structure diagram of the self-adaptive damping flexible spring based on shear thickening fluid - particulate composite material of the present invention.

[0022] Figure 3 is the shape schematic diagram of the inner and outer tube walls of the silica gel corrugated tube of the present invention.

[0023] Figure 4a is the external structure diagram of the sleeve of the present invention.

[0024] Figure 4b is the internal structure diagram of the sleeve of the present invention.

[0025] Figure 5 is the load-displacement curve diagram of the flexible spring (filled with 6mm spherical particle and shear thickening fluid composite material) at different compression rates.

[0026] Figure 6 is the load-displacement curve diagram of the comparison spring (filled with shear thickening fluid) at different compression rates.

[0027] Figure 7 Hysteresis curves of composites of 4 mm spherical particles and shear thickening fluid with an excitation amplitude of 10 mm at different excitation frequencies.

[0028] Figure 8 Hysteresis curves of composites of 6 mm spherical particles and shear thickening fluid with an excitation amplitude of 10 mm at different excitation frequencies.

[0029] Figure 9 Hysteresis curves of composites of 8 mm spherical particles and shear thickening fluid with an excitation amplitude of 10 mm at different excitation frequencies. Detailed implementation manners

[0030] The present invention will be further described below in conjunction with embodiments, but the scope protected by the present invention is not limited to the

[0031] scope.

[0032] Embodiment 1

[0033] According to Figures 1 - 4b , an adaptive damping flexible spring based on a shear thickening fluid-particle composite includes an annular silica gel corrugated pipe 2. A cylindrical cavity is left in the middle of the annular structure of the silica gel corrugated pipe 2, and the cylindrical cavity extends along the length direction of the silica gel corrugated pipe 2; the bottom of the silica gel corrugated pipe 2 is connected to a base 1, and a sleeve 5 is embedded at the top of the silica gel corrugated pipe 2;

[0034] The silica gel corrugated pipe 2 includes an inner pipe wall 21 and an outer pipe wall 22 arranged coaxially. A filler cavity is formed between the inner pipe wall 21 and the outer pipe wall 22, and the filler cavity has good airtightness; the filler cavity is filled with a shear thickening fluid 10, spherical particles 3 and compressible gas 8.

[0035] The longitudinal cross-sectional shapes of the inner pipe wall 21 and the outer pipe wall 22 of the silica gel corrugated pipe 2 are corrugated lines that periodically change in the length direction of the silica gel corrugated pipe 2; the corrugated line of the inner pipe wall 21 is an inner corrugation, and the corrugated line of the outer pipe wall 22 is an outer corrugation; among them, the inner corrugation sine curve is R1 is the radius of the top of the inner pipe wall; the outer corrugation sine curve is R2 is the radius of the top of the outer pipe wall, where R2 - R1 = 10 mm, A is the amplitude of the inner corrugation and the outer corrugation, L is the length of the inner corrugation and the outer corrugation, L / N is the wavelength, and N is the number of corrugation cycles in the length direction of the silica gel corrugated pipe 2.

[0036] A sealing ring 4 is provided at the joint where the bottom of the sleeve 5 is attached to the silica gel corrugated pipe 2, and a gasket 9 is provided between the lower end of the sealing ring 4 and the outer pipe wall 22.

[0037] The upper surface of the base 1 has a first annular groove that mates with the bottom of the silicone bellows 2, and the bottom of the silicone bellows 2 is connected to the first annular groove.

[0038] The top end of the sleeve 5 is provided with a second annular groove, a sealing gasket 6 is provided in the second annular groove, and a top cover 7 that is embedded in the second annular groove and contacts the sealing gasket 6 is provided on the top of the sleeve 5. The top cover 7 and the sleeve 5 are fixedly connected by glue.

[0039] As Figure 2 shown, the material of the silicone bellows 2 in this embodiment is replica soft rubber silicone, its Shore hardness is 70, where the radius R1 of the inner tube wall = 17 mm, the radius R2 of the outer tube wall = 27 mm, the amplitudes of its inner and outer corrugations are the same A = 4 mm, the wall thicknesses of the inner tube wall 21 and the outer tube wall 22 are the same δ = 2 mm, the number of corrugations of the inner and outer bellows is the same N = 6, and the lengths of the inner and outer bellows are the same L = 96 mm. Therefore, the wavelengths of the inner and outer corrugations are the same L / N = 16 mm; the spherical particles 3 are made of polyoxymethylene resin (POM), with a density of 1.41 g / cm^3 and a particle diameter of 6 mm. The mass fraction of the shear thickening fluid is 41%.

[0040] The filling process of the silicone bellows is as follows: Fill the bellows cavity with spherical particles to the height position of 4 layers of corrugation numbers, and shake the bellows during the addition process to make the spherical particles evenly distributed; then add the shear thickening fluid to the same height position to form a composite material. Finally, fill the compressible gas nitrogen to replace the air inside the cavity. The volume ratio of the composite material to the compressible gas is 2:1.

[0041] The preparation process of the shear thickening fluid is as follows: The dispersed phase of the shear thickening fluid filled in the silicone bellows cavity is corn starch particles, the dispersion medium is deionized water, and cesium chloride reagent is used as the stabilizing phase at the same time; First, the cesium chloride reagent is added to deionized water to prepare a cesium chloride solution with a density of 1.59 g / cm^3, which is the same as the density of the corn starch particles. The mass fraction of cesium chloride in the cesium chloride solution is 49.5%. Then, corn starch particles are added to prepare a corn starch particle shear thickening fluid, and the mass fraction of the corn starch particles is 41%. Concentration: Corn starch particles 651.9 g / L; Cesium chloride reagent 464.6 g / L

[0042] Example 2

[0043] The self-adaptive damping flexible spring based on the shear thickening fluid-particle composite material described in Example 1 was subjected to a uniaxial compression experiment on an Instron E10000 testing machine. The maximum compression stroke was set to 20 mm, and load-displacement curves were obtained by conducting experiments at different compression rates of 0.1, 10, 100, and 500 mm / s, reflecting the variable stiffness characteristics of the flexible spring. According to Figure 5As shown, under quasi-static compression and low-speed compression rates (0.1 mm / s and 10 mm / s), the load-displacement curve of the flexible spring remains basically unchanged. At this time, the shear thickening fluid has no shear thickening effect, and the flexible spring provides static bearing capacity by forming a skeleton through the stacking of spherical particles. As the compression rate increases, the stiffness of the flexible spring increases significantly, reflecting its variable stiffness characteristics under high-frequency loads.

[0044] Comparative Example 1

[0045] Take a comparison spring, with the other conditions being the same as those of the self-adaptive damping flexible spring in Example 1, except that the inner cavity of the silicone bellows 2 is only filled with the shear thickening fluid to the height of four corrugation numbers, and no spherical particles 3 are filled. Conduct a uniaxial compression experiment on this comparison spring on an Instron E10000 testing machine, set the maximum compression stroke to 20 mm, and conduct experiments at different compression rates of 0.1, 10, 100, and 500 mm / s to obtain the load-displacement curve. According to the experimental diagram, combined with Figure 5 As shown, under quasi-static compression and low-speed compression rate ratios, the load-displacement curve of the flexible spring remains basically unchanged (0.1 mm / s and 10 mm / s). At the same time, the load force at the maximum compression stroke is much smaller than that of the flexible spring filled with the shear thickening fluid + 6 mm particles (18 N compared to 138 N); this indirectly reflects the static bearing capacity of the self-adaptive damping flexible spring based on the shear thickening fluid-particle composite material due to the addition of spherical particles. As the compression rate increases, the shear thickening fluid in the flexible spring undergoes shear thickening due to high-speed compression and shear, and the stiffness increases to a certain extent.

[0046] Example 3

[0047] Based on the self-adaptive damping flexible spring of Example 1, which is based on a shear thickening fluid-particle composite material, the difference is that the diameter of the spherical particles 3 is 4 mm.

[0048] Example 4

[0049] Based on the self-adaptive damping flexible spring of Example 1, which is based on a shear thickening fluid-particle composite material, the difference is that the diameter of the spherical particles 3 is 8 mm.

[0050] Example 5

[0051] Conduct cyclic loading experiments on the self-adaptive damping flexible springs of Example 3, Example 1, and Example 4 on an Instron E10000 testing machine respectively. Set the excitation amplitude to 10 mm, the excitation load type to sinusoidal excitation, and conduct cyclic loading at frequencies of 0.5 Hz, 3 Hz, and 8 Hz respectively. Complete 15 cycles, and take the experimental data of the 7th cycle. The test results of Example 3 correspond to Figure 7 , the test results of Example 1 correspond to Figure 8, corresponding to the test results of Example 4 Figure 9 ; It can be seen that the area of the hysteresis loop in the hysteresis curve diagram increases with the increase of the excitation frequency, and the energy dissipation increases significantly; According to Figures 7 - 9 the comparison between the figures, for the adaptive damping flexible spring based on the composite material of spherical particles with different diameters and shear thickening fluid, the change amplitude of the hysteresis loop area varies with the excitation frequency. The change amplitude of the 4mm spherical particles and the shear thickening fluid ( Figure 7 ) is large, and the area of the hysteresis loop increases more with the increase of the excitation frequency, reflecting excellent adaptive damping effect and large increase in energy dissipation; The change amplitude of the 6mm spherical particles and the shear thickening fluid ( Figure 8 ) is moderate, with good adaptive damping effect and moderate increase in energy dissipation; The change amplitude of the 8mm spherical particles and the shear thickening fluid ( Figure 9 ) is small, with general adaptive damping effect and general increase in energy dissipation.

Claims

1. An adaptive damping flexible spring based on a shear thickening fluid-particle composite material, characterized in that: It includes an annular silicone corrugated pipe (2). There is a cylindrical cavity in the middle of the annular structure of the silicone corrugated pipe (2), and the cylindrical cavity extends along the length direction of the silicone corrugated pipe (2); the bottom of the silicone corrugated pipe (2) is connected to a base (1), and a sleeve (5) is embedded at the top of the silicone corrugated pipe (2). The silicone corrugated pipe (2) includes an inner pipe wall (21) and an outer pipe wall (22) arranged coaxially. A filling cavity is formed between the inner pipe wall (21) and the outer pipe wall (22), and the filling cavity has good airtightness; a shear thickening fluid (10), spherical particles (3) and compressible gas (8) are filled in the filling cavity.

2. The adaptive damping flexible spring based on a shear thickening fluid-particle composite material according to claim 1, characterized in that: The longitudinal cross-sectional shapes of the inner tube wall (21) and the outer tube wall (22) of the silicone corrugated tube (2) are corrugated lines that periodically change in the length direction of the silicone corrugated tube (2); the corrugated line of the inner tube wall (21) is an inner corrugation, and the corrugated line of the outer tube wall (22) is an outer corrugation; among them, the inner corrugation sine curve is R1 is the radius of the top end of the inner tube wall; the outer corrugation sine curve is R2 is the radius of the top end of the outer tube wall, where R2 - R1 = 10 mm, A is the amplitude of the inner and outer corrugations, L is the length of the inner and outer corrugations, L / N is the wavelength, and N is the number of corrugation cycles in the length direction of the silicone corrugated tube (2).

3. The adaptive damping flexible spring based on a shear thickening fluid-particle composite material according to claim 1, wherein: A sealing ring (4) is arranged at the joint where the bottom of the sleeve (5) fits with the silicone corrugated pipe (2), and a gasket (9) is arranged between the lower end of the sealing ring (4) and the outer pipe wall (22).

4. An adaptive damping flexible spring based on a shear thickening fluid-particle composite material according to claim 1, characterized in that: The material of the spherical particles (3) is polyoxymethylene resin with a density of 1.41 g / cm 3 , and the particle diameter is 4 - 8 mm.

5. An adaptive damping flexible spring based on a shear thickening fluid-particle composite material according to claim 1, characterized in that: The thickness δ of the inner pipe wall and the outer pipe wall is 2 mm.

6. The self-adaptive damping flexible spring based on a shear thickening fluid-particle composite material according to claim 1, wherein: There is a first annular groove on the upper surface of the base (1) that matches the bottom of the silicone corrugated pipe (2), and the bottom of the silicone corrugated pipe (2) is connected to the first annular groove.

7. The adaptive damping flexible spring based on a shear thickening fluid-particle composite material according to claim 1, characterized in that: The top end of the sleeve (5) is provided with a second annular groove. A sealing gasket (6) is arranged in the second annular groove. A top cover (7) that is embedded in the second annular groove and contacts the sealing gasket (6) is arranged at the top of the sleeve (5), and the top cover (7) and the sleeve (5) are connected and fixed by glue.

8. An adaptive damping flexible spring based on a shear thickening fluid-particle composite material according to claim 1, characterized in that: The material of the silicone corrugated pipe (2) is a replica soft rubber mixture, and its Shore hardness is 70; the materials of the base (1), the sleeve (5), the top cover (7) and the sealing gasket (6) are polylactic acid.

9. The self-adaptive damping flexible spring based on a shear thickening fluid-particle composite material according to claim 1, characterized in that: The compressible gas (8) is nitrogen.

10. The self-adaptive damping flexible spring based on a shear thickening fluid-particle composite material according to claim 1, characterized in that: The compressible gas (8) accounts for 1 / 3 of the volume of the filling cavity.

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