铝合金梁受低速撞击动态响应的试验研究

EXPERIMENTAL INVESTIGATION ON RESPONSES OF ALUMINUM BEAMS TO LOW VELOCITY IMPACTS

  • 摘要: 梁受横向撞击时,其撞击力、局部变形和整体变形等动态响应受到撞击体质量、撞击速度、撞击位置以及梁刚度特性等因素的影响,研究这些参数对动力响应以及对撞击局部效应和整体效应的影响规律,是合理提出抗撞击防护手段的基础。该文利用低速落锤冲击试验装置进行了铝合金梁横向撞击试验,着重研究不同撞击速度、撞击位置和试件刚度等因素对铝合金梁所受撞击力、整体与局部变形、应变与能量等的影响规律。实验结果表明:随着撞击速度的增加,试件吸收能量的速率增大,撞击力幅值不断增加,撞击荷载主峰值段的持续时间减小;试件的整体变形和局部变形都明显增大,但局部效应相对增加更为显著;随着试件刚度(厚度)的增加,试件受相同速度撞击的吸收能量速率增大,撞击力荷载峰值显著增加;试件整体变形减小,而局部变形增加,说明试件刚度越大,其撞击整体效应减弱,而局部效应增强;试件受撞击后整体变形与撞击力相比明显具有滞后性,表明整体效应滞后于局部效应。

     

    Abstract: For beams under transverse impacts, the influences of the projectile's mass and velocity, impact position and target stiffness, on the dynamic responses and impact effects of beams, such as impact force, global deformation and local deformation, is fundamental in anti-impact structural design. Six aluminum beams were transversely impacted by a low-velocity impact machine herein. Influences of parameters (i.e., velocity, impact position and specimen stiffness) on dynamic responses (i.e., impact force, global and local deformation, strain and energy) of beams were analyzed. The results revealed:with an increasing impact velocity, the specimen's energy absorption speed and impact force amplitude increased, but the peak value duration of impact load reduced; both global and local deformation increased, but the increase in the local effects was more significant; with an increasing specimen stiffness (i.e., thickness), energy absorption speed and the peak value of impact force increased under the same impact velocity; the global deformation decreased while the local deformation increased, indicating that with an increasing stiffness, the global effect was weakened while the local effect was enhanced; compared with the impact force, the global deformation was obviously lagged, indicating that the global effect was lagged behind the local effect.

     

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