落锤冲击气囊施加均布动荷载的试验方法

在结构构件上施加均布冲击(爆炸)荷载一直是动力试验领域的难题。提出了一种落锤冲击气囊施加均布动荷载的试验装置，和一个双自由度弹簧阻尼冲击加载简化分析模型；给出了该模型的基本力学方程、边界条件和求解方法，并进行了有限元验证；建立了所提出冲击加载试验装置的精细化有限元模型，分析了构件上各受荷区域的荷载均布情况，验证了所提出装置的可行性。基于所建立的简化分析模型，讨论了刚度、荷载作用时间和阻尼比等关键参数，对构件上动荷载的影响，并给出了基本规律。计算结果表明，在选定合适的参数后，落锤冲击气囊试验装置能够较好地模拟构件上的均布动荷载，为实验室中进行爆炸冲击试验提供了一种可能。

Experimental method of imposing uniform dynamic loads by impacting an airbag with the drop hammer

It is very difficult to apply a uniform impact (explosion) loads on the structural member in the laboratory. We presented an innovative loading apparatus using a drop hammer impacting on the airbag to simulate the uniform loads,and proposed a two-DOF (degree-of-freedom) analytical model. The fundamental mechanical equation, boundary conditions and solution method were given and verified. A fine finite element model was established and the loading effects on the divided area were compared to verify the feasibility of presented apparatus. Some key factors of the dynamic loads were also discussed, including stiffness, load duration and damping ratio.The results show that the presented apparatus can be applied to simulate the uniform dynamic loads with choosing parameters,which provides a possibility for experiments simulating blast loading in the laboratory.