弯载下周向壁穿裂纹位于固定端的圆柱壳弹塑性解  

ELASTIC-PLASTIC SOLUTIONS FOR CIRCUMFERENTIAL THROUGH-CRACKS AT THE FIXED END OF CYLINDRICAL SHELLS LOADED BY BENDING

作　　者：赵耀[1] 何书韬[1] 

机构地区：[1]华中科技大学船舶与海洋工程学院,武汉430074

出　　处：《固体力学学报》2012年第4期386-394,共9页Chinese Journal of Solid Mechanics

基　　金：国家自然科学基金项目(50579023)资助

摘　　要：金属圆柱壳结构常见于各种大型复杂结构系统中.这类构件在其端部与其它构件相连接是工程上常见的结构形式.由于连接处焊接热影响或实际复杂内力的作用,在连接处产生疲劳裂纹的几率相对增大;另一方面,由于高韧性材料的应用,使得弹塑性裂纹更为常见.然而到目前为止,尚无针对这类问题的弹塑性理论解析解.论文针对受弯曲载荷作用下的周向壁穿裂纹位于固定端的圆柱壳,基于半膜力壳理论及Dugdale模型,推导了裂纹尖端张开位移(CTOD)和裂纹尖端张开角度(CTOA)等一套相对完整的弹塑性解析解.该解除少数数值求根外,均为显式表达,可用于裂纹起裂、撕裂计算,追踪此类由弹塑性裂纹的存在所引起的圆柱壳结构的柔度以及裂纹撕裂条件下的极限承载能力等的变化过程,弥补了这类工程问题解析解空缺的不足.Metal cylinder shell structures are very common components in the large complex structure systems,and the end of the shell is usually connected with other components.Due to the heat effect of the welding and real complicated inherent stress,the possibility of engendering fatigue cracks increases.With the application of high toughness material,elastic-plastic crack becomes more popular.However,there is no elastic-plastic theoretical analytical solution to such problem until now.In this paper,a set of complete elastic-plastic solutions for circumferential through-cracks at the fixed end of cylindrical shells loaded by bending,such as the crack tip opening displacement（CTOD） and crack tip opening angle（CTOA）,are developed according to the semi-membrane theory of cylindrical shells and with the use of Dugdale model.The proposed solutions are obtained mostly by explicit equations except a few numerical root-finding calculations and could be used for the calculation of crack initiation and stable crack growth,which describe the whole changing process of the structure compliance and ultimate carrying capacity with the presence of the elastic-plastic crack.This method has filled the gap of analytical solution to such engineering problems.

关 键 词：周向壁穿裂纹 圆柱壳 DUGDALE模型 固定端 弯曲载荷 

分 类 号：O346.1[理学—固体力学]