受刚体碰撞方管柱考虑局部屈曲时的弹塑性冲击荷载  

ELAS-PLASTIC IMPACTS BY RIGID BODY ON RECTANGLE TUBE COLUMNS CONSIDERING LOCAL BUCKLING

作　　者：剧锦三[1] 杨蔚彪 蒋秀根[1] 

机构地区：[1]中国农业大学土木系,北京100083 [2]中国建筑标准设计研究院,北京100044

出　　处：《工程力学》2008年第7期190-195,共6页Engineering Mechanics

基　　金：十一五科技支撑计划课题“资源节约关键技术标准研制”(2006BAK04A03);中国农业大学科研启动基金(2006022)

摘　　要：使用壳单元建立方管柱模型,用数值方法跟踪方管柱受到刚体撞击的全过程,得到不同质量比、不同冲击速度时的弹性和弹塑性冲击荷载,比较了方管模型柱和杆模型柱的冲击荷载结果并进行了分析。结果表明:对于弹性方管模型,当质量比越小、冲击速度越大时,冲击荷载峰值越大;接触时间也越长;局部屈曲亦越明显,造成管模型的冲击荷载峰值比相同参数杆模型的冲击荷载峰值降低也越多,因此管模型的冲击荷载峰值和速度不成线性关系。方管中的双向应力波导致管模型的冲击荷载曲线和只有单向应力波的杆模型的曲线有所不同,后者更光滑一些。对于弹塑性方管模型,和弹塑性杆类似,由于塑性的发展,弹塑性管模型的冲击荷载峰值随冲击速度的提高而增大,但是随速度变化的冲击荷载峰值曲线比弹性模型的平缓很多。由于管模型的局部屈曲效应,其弹塑性冲击荷载总是小于杆模型的冲击荷载。冲击速度越大,质量比越小,弹塑性管模型的冲击荷载峰值越大且接触时间越长。The rectangle tube columns are modeled by shell elements, and their behaviors under rigid body impacts are investigated. Tracing the whole impact procedure using numerical method, this paper obtains elastic and elas-plastic impact loads with variant mass ratios and impact speeds. The impact loads exerted on rectangle tubes are compared with those of the bar models. The calculation results show that for elastic rectangle tubes, the bigger the mass ratio and the higher the rigid body speed, the bigger the peak elastic impact load, the longer the contact time, and the more significant reduction of the peak impact load due to local buckling. Therefore, the peak impact load of the rectangle tube is not proportional to the rigid body speed. Due to the bidirectionality of stress wave in the tubes, the impact load curves of the tube model are not as smooth as those of the bar model which has unidirectional stress wave. Similar to elas-plastic bars, the peak impact load on elas-plastic tubes increases with the speed of rigid body because of the expanding of plasticity. But the changing of the peak impact load on elas-plastic tube is much smoother than that on elastic tube. Because of local buckling, the peak elas-plastic impact load of rectangle tubes is always smaller than that of bars. The higher the rigid body speed and the smaller the mass ratio, the bigger the peak impact load of rectangle tubes and the longer the contact time.

关 键 词：冲击荷载 弹塑性冲击 数值解 方管柱 质量比 局部屈曲 

分 类 号：O347.1[理学—固体力学] TU318[理学—力学]