非正态参数二维分叉裂纹扩展寿命的可靠性分析  

Reliability Analysis for Propagation Life of Bifurcated Crack with Non-normal Random Parameters

作　　者：张艳林[1] 张义民[1] 金雅娟[1] 张艳芳[2] 

机构地区：[1]东北大学,沈阳110004 [2]防灾科技学院,三河065201

出　　处：《中国机械工程》2010年第22期2722-2725,共4页China Mechanical Engineering

基　　金：国家高技术研究发展计划(863计划)资助项目(2007AA04Z442);国家自然科学基金资助重点项目(50875039);"十一五"国家科技支撑计划资助项目(2009BAG12A02);沈阳市人才资源开发专项资金资助项目(2007010103001);沈阳市科学技术计划科技攻关项目(1071057-9-00)

摘　　要：以材料属性和载荷为随机变量,以控制分叉裂纹扩展的修正Paris-Erdogan公式为基础,结合建立在随机有限元法基础上的四阶矩可靠性分析方法,提出了基本变量服从任意分布时,二维分叉裂纹扩展寿命可靠度的计算方法,裂纹扩展方向采用最大周向应力准则。以平面二维分叉裂纹为例分析了其扩展寿命及可靠度变化规律,结果表明,随着裂纹的扩展,平板剩余寿命逐渐缩短,剩余寿命对设计寿命的可靠度随着裂纹扩展而逐渐降低。Stochastic finite element method,fourth moment reliability method were employed to present a reliability-based method for crack growth life of structures with non-normal random variables in which material properties and applied loadings were considered as random parameters.Taking reliability-based analysis for crack growth life of a plate with a bifurcated crack and subjected to constant distributed stress at updown edges of the plate as a numerical example in which Paris-Endogan formula were used and the direction of the crack propagation followed the maximum circumferential stress criterion.The numerical results show that the fatigue life of the plate with moment method;reliabilitybifurcated crack are longer than that of the plate without bifurcated crack for the same crack growthsize,and the life reliability of the plate is descendent as the crack grows.

关 键 词：裂纹扩展寿命 分叉裂纹 非正态随机参数 四阶矩法 可靠性 

分 类 号：O346.2[理学—固体力学]