摘要
为了研究在冲击荷载下固支梁的弹塑性动力响应,首先利用能量法推导固支梁在冲击荷载下动力响应的简化计算方法,将跨中挠度和冲击荷载响应作为梁动力响应的评价指标;然后通过一些算例对固支梁与简支梁的动力响应进行对比来探讨不同边界条件对受力的影响,为结构抗冲击安全设计提供指导;最后利用有限元软件ANSYS/LSDYNA模拟固支梁在外部冲击物碰撞作用下的动力响应并与解析结果进行对比,在分析时考虑材料应变率和接触变形.结果表明:提出的弹塑性动力响应判别方法、动力响应简化计算方法和评价指标都是可行的;固支梁相对于简支梁更有利于承受冲击荷载;当质量比与冲击物速度比较适中时,跨中挠度和冲击荷载响应的解析解和数值解相符较好;在相同的冲击能量下,冲击物质量和速度所占的比例不同,动力响应所经历的时间历程不同.
In order to investigate the dynamic response of elasticity-plasticity of clamped beam subjected to impact load,a simplified method for calculation of the dynamic response was derived with energy method first,and the mid-span deflection and the response to the impact load were taken as evaluation index of the dynamic response.Then,the dynamic response of clamped beam and simply supported beam were compared by means of some calculation examples to explore the influence of different boundary conditions on the stress,providing aguidance for safety design of anti-impact structure.Finally,considering material strain rate and contact deformation and using finite element software ANSYS\\LSDYNA,the dynamic response of clamped beam to external impact of falling body was simulated and compared with the analytical result.The result shows that the method of dynamic response discrimination,simplified calculation method,and evaluation index proposed are all feasible and compared with simply supported beam,clamped beam will be more beneficial to bear impact load.The analytical solutions of mid-span deflection and impact load are well consistent to the numerical ones when the mass ratio and falling velocity of impacting body is appropriate.With the same impact energy,the time course of dynamic response will be different due to the different proportion of impact mass and falling speed of impacting body.
出处
《兰州理工大学学报》
CAS
北大核心
2017年第3期133-139,共7页
Journal of Lanzhou University of Technology
基金
国家自然科学基金(51468054
51608245)
宁夏高等学校科学研究资助项目(NGY2016150)
关键词
固支梁
冲击荷载
简化计算方法
动力响应
评价指标
clamped beam
impact load
simplified calculation method
dynamic response
evaluation index
