低温冲击环境下的加筋板骨材裂纹扩展分析  

Crack growth analysis of stiffeners in a stiffened panel under low-temperature impact

作　　者：李恒[1] 杨飏[1] 

机构地区：[1]大连理工大学船舶工程学院,辽宁大连116024

出　　处：《哈尔滨工程大学学报》2017年第4期521-526,共6页Journal of Harbin Engineering University

基　　金：国家自然科学基金项目(51261120376)

摘　　要：针对低温冲击作用下含裂纹船海结构物易呈脆性断裂破坏的问题,选取加筋板单元进行了面外横向冲击载荷作用下裂纹发展路径和断裂规律的研究。构造了骨材裂纹I型和I-II复合型动态断裂的条件,使用局部应力与损伤模型控制裂纹起裂和发展;采用扩展有限单元法进行数值求解。研究表明:本文方法可以很好的预测此类问题中的裂纹发展;研究I型开裂发现,断裂能减小,裂纹扩展速度加快;研究I-II复合型开裂发现,裂纹与骨材垂向中心线距离减小或初始长度增加,裂纹起裂时间变早且整体发展路径偏离裂尖初始方向程度减小。Ship and marine structures with cracks inside exposed to the cold tend to fail in typical brittle fractures under external shock loading. To solve this problem,we selected a stiffened plate unit to analyze its crack propaga-tion path and fracture laws under lateral impact. We created mode Ⅰ and mixed-mode Ⅰ-Ⅱ dynamic crack propagation conditions,introduced a local stress and damage model to control the initiation and growth of cracks,and adopted the extended finite element method for our numerical calculations. The research results show that the approach we used can effectively predict crack propagation. The mode-Ⅰ fracture research results show that crack growth speed increases as the fracture energy decreases. The mode Ⅰ-Ⅱ fracture research results show that cracks initiate earlier and the whole propagation path deviates more from the initial direction of the crack tip as the crack＇s distance to the stiffener＇s vertical center line decreases or the crack＇s initial length increases.

关 键 词：初始裂纹 加筋板 低温环境 横向冲击 动态断裂能 裂纹扩展路径 局部分析方法 

分 类 号：U663.2[交通运输工程—船舶及航道工程]