冲击荷载作用下Levy型索穹顶结构动力响应分析

Dynamic Response of Levy-Type Cable Dome Structures Under Impact Loads

建立Levy型索穹顶结构有限元分析模型,给出有限元结果合理性的判定准则,提出冲击失效准则。进行大量冲击工况下的动力响应全过程分析,给出杆件破坏分布规律和失效模式,揭示结构在竖向冲击荷载作用下的失效机理。依据冲击失效机理及参数分析,提出抗冲击措施。研究结果表明:所有冲击工况均符合冲击判定准则,在所选竖向冲击荷载范围内,Levy型索穹顶结构的失效模式可分为4种,即结构轻度损伤、结构局部1级失效、结构局部2级失效和结构整体破坏。随着冲击动能的增加,结构的动力响应模式逐渐呈模式1→模式2→模式3→模式4的发展趋势。通过分析可知,结构的动力响应模式由结构的能量吸收值及构件两端速度差决定。

The finite element model of a Levy-type cable dome structure was established,and this model could provide the criteria for determining the rationality of finite element results.The impact failure criterion was proposed.The full analysis of dynamic response under a large number of impact conditions was conducted,and the failure distribution and failure modes of the members of the structure were given,which reveals the failure mechanism under vertical impact loads.Based on the analysis of impact failure mechanism and parameters,a set of anti-impact measures were proposed.The research results show that all impact conditions follow the impact criteria.Within the selected vertical impact load range,the failure modes of the Levy-type cable dome structure are divided into four types,which are slight structural damage,local level 1 structural failure,local level 2 structural failure,and overall structural damage.As the impact kinetic energy increases,the dynamic response mode of the structure gradually prog resses from mode 1 to mode 2,then to mode 3,and finally to mode 4.The dynamic response mode of the structure is determined by the energy absorption value of the structure and the velocity difference between the two ends of the member.