硅基应变率敏感性吸能材料吸能效果试验分析

Study on jerky dynamic characteristics of energy absorbing materials based on impact test

  • 摘要: 为研究聚硼硅氧烷型硅基应变率敏感性吸能材料吸能效果和对冲击载荷动力学响应特性,在煤炭科学研究总院北京矿山支护设备检测检验中心6000 kN立柱冲击试验台上进行了吸能材料冲击试验,运用猝量理论对硅基应变率敏感性吸能材料冲击载荷动力学响应特性和吸能效果进行了研究,推导出随时间呈线性变化的变外力作用下受冲击物体速度、位移与冲击功公式,结合试验数据对理论结果进行了分析验证。结果表明,聚硼硅氧烷型硅基应变率敏感性吸能材料具有快响应、强吸能、长延时、去峰消振的特点。当受聚硼硅氧烷型硅基应变率敏感性吸能材料保护的立柱受冲击时,吸能材料响应时间在35 ms左右,冲击过程中立柱下腔最大压力36.85 MPa,而当无吸能材料保护的立柱受冲击时下腔最大压力为59 MPa。有吸能材料保护的立柱受冲击时的下腔最大压力是无吸能材料保护的立柱受冲击时下腔最大压力的61.9%,吸能材料吸收的能量占整个冲击能量的80%,冲击时间是无吸能材料受冲击时间的8倍,冲击过程中立柱下腔乳化液压力增长稳定,基本没有波动,除吸能材料与试验台接触面处出现塑性变形外,吸能材料主体结构完好,未出现显著破坏。对比分析了猝量理论结果与相关试验数据,2者基本一致,验证了理论结果的正确性。所得结论和理论计算方法可为液压支架防冲材料的设计选型提供参考。

     

    Abstract: In order to study the energy absorption effect and dynamic response characteristics of silicon-based strain rate-sensitive energy-absorbing materials under impact load, impact tests of energy-absorbing materials were conducted on the 6000 kN hydraulic leg impact test platform at the Beijing Mining Support Equipment Testing and Inspection Center of the Coal Science Research Institute. The jerky theory was employed to analyze the energy absorbing effect and dynamic response. Mathematical expressions relating object speed, displacement, and impact energy were derived for varying external forces, and theoretical predictions were validated by experimental measurements. The results indicate that the silicon-based material exhibits rapid response time, high energy absorption capacity, prolonged time delay, peak removal, vibration elimination and damage resistance during impact. Specifically, the response time of the energy-absorbing material was measured to be approximately 35 ms when tested with the hydraulic leg, the maximum pressure in the lower chamber of the hydraulic leg during the impact process is 36.85 MPa, while the hydraulic leg without energy-absorbing material protection has a maximum pressure of 59 MPa when impacted. During the impact, the lower chamber of the hydraulic leg reduced by 61.9% maximum pressure, with the energy-absorbing material accounting for 80% of the total impact energy absorbed. Moreover, the impact time was 8 times longer than that of the non-energy absorbing material, while remaining stable with no significant fluctuation during the process. The structure of the material also remained intact except for some plastic deformation on the contact surface. These findings, consistent with the jerky theory, provide valuable insights for the design and selection of materials for hydraulic-powered support in anti-impact applications.

     

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