框架结构在撞击荷载作用下的动力响应分析

以某工程局部9层框架为研究对象,利用有限元软件LS-DYNA模拟汽车撞击钢管混凝土柱-钢梁混合框架、钢筋混凝土框架以及钢框架三种框架结构的过程,获得了三种框架结构钢材应力云图、混凝土损伤云图、撞击力时程曲线及结构变形等动力响应。分析了三种框架结构在撞击荷载作用下的破坏模式,分析结果表明:受到撞击荷载作用后,钢管混凝土柱-钢梁混合框架的动力响应具有局部性,而钢筋混凝土框架整体遭到严重破坏,结构发生连续性倒塌;钢管混凝土柱-钢梁混合框架的抗撞击性能远优于钢筋混凝土框架。并根据研究结果,提出框架结构的变形限值条件以及撞击力代表值的计算公式,用以评价、比较框架结构的抗撞击性能,给出了在实际工程中提高框架结构抗撞击性能的设计建议。

Dynamic response analysis of frame structure under impact load action

Taking a nine story frame as the research object,LS-DYNA software was used to simulate the processes of automobile impacting the frame structures of concrete filled steel tubular(CFST)column-steel beam hybrid frame,reinforced concrete frame and steel frame.The dynamic responses of the three frame structures were obtained including steel stress cloud chart,concrete damage cloud chart,impact force time-history curve and structural deformation.The failure modes of the three frame structures under impact load action were analyzed.The results show that the dynamic response of CFST column-steel beam hybrid frame is local under the impact load action,while the whole reinforced concrete frame is seriously damaged and the structure collapses continuously.The impact resistance of CFST column-steel beam hybrid frame is much better than that of reinforced concrete frame.According to the research results,the deformation limit conditions of frame structure and the calculation formula of impact force representative value were put forward to evaluate and compare the impact resistance of frame structures,and the design suggestions were given for improving the impact resistance of frame structure in practical engineering.