刚性质量对自由梁的弹塑性次碰撞的若干特征  

Characteristics of elastic-plastic sub-impacts of free-free beam struk by rigid mass

作　　者：孔德平[1] 杨钧[1] 尹晓春[1] 沈煜年[1] 骞朋波[1] 

机构地区：[1]南京理工大学力学与工程科学系,江苏南京210094

出　　处：《南京理工大学学报》2013年第4期613-620,共8页Journal of Nanjing University of Science and Technology

基　　金：国家自然科学基金(10872095);教育部博士点基金(20123219110036;20123219120042)

摘　　要：该文基于Rayleigh梁理论,采用局部弹塑性接触模型,结合有限差分方法和碰撞-分离条件,研究了钝圆柱头质量水平碰撞自由梁过程中的弹塑性次碰撞过程。研究发现,整个水平碰撞包含了复杂的弹塑性次碰撞过程,整个碰撞过程由分别位于碰撞压缩相内和恢复相内的两个明显的次碰撞区组成。第二碰撞区的出现,导致梁出现了二次瞬态变形激发现象。碰撞激发了梁一阶位移响应和高阶速度响应,一阶位移响应与次碰撞区的形成有着本质的联系,次碰撞的形成过程与高阶速度响应密切相关。另外,次碰撞显著地改变了碰撞能量的传递方式,导致了单向、间歇式的碰撞能量传递模式。研究表明,次碰撞与次碰撞激发的自由梁响应之间存在着复杂的耦合力学机制。Based on the Rayleigh theory of beams,the impact problem of a free-free beam struck horizontally by a round-nosed rigid mass is simulated by the finite difference method and the impact-separation conditions.In order to obtain the multiple impact force,a uniaxial compression elastic-plastic contact model is employed.It is found that the horizontal impact is indeed a complicated process including elastic plastic sub-impacts.There are two sub-zones of sub-impacts which are in the compression zone and the recovery zone,respectively.The second sub-zone causes the re-excitation of transient deformation of the beam.The elastic-plastic sub-impacts excite the first-order displacement response and high-order velocity responses of the beam,where the first-order displacement response is intrinsically linked to the formation of the sub-zones of sub-impacts,and the high-order velocity responses make strong influence upon the processes of sub-impacts.In addition,the transferring way of impact energy is changed obviously by sub-impacts,and a unidirectional,non-continuous,intermittent impact energy transferring model reveals.The present investigation shows that there is a complicated coupling mechanism between the elastic-plastic sub-impacts and the beam responses excited by sub-impacts.

关 键 词：刚性质量 自由梁 碰撞力 次碰撞 弹塑性变形 有限差分法 

分 类 号：V214[航空宇航科学与技术—航空宇航推进理论与工程]