缺口件疲劳损伤累积规律的研究  

Fatigue damage accumulation rule of notched specimen

作　　者：张莉[1] 赵兵[1] 郭宝科[1] 

机构地区：[1]哈尔滨工业大学航天科学与力学系,哈尔滨150001

出　　处：《哈尔滨工业大学学报》2008年第11期1703-1706,共4页Journal of Harbin Institute of Technology

基　　金：国家自然科学基金资助项目(10502018);黑龙江省博士后基金资助项目

摘　　要：为解决传统疲劳方法对于缺口件疲劳寿命估算不准确的问题,引入疲劳损伤累积的概念.利用有限元分析方法,计算了中心圆孔试件在4种疲劳载荷作用下缺口处的应力-应变响应.采用坐标变换的方法得到缺口处在4种疲劳载荷作用下任意材料平面上的应力、应变分量.选取6种损伤参量进行研究,计算得到6种损伤参量随截面位置的变化情况,进而可以确定最大疲劳损伤.为了获得6种损伤模型的累积规律,计算在不同循环内的最大累积损伤,进而获得最大疲劳累积损伤与循环次数的关系.结果表明:中心圆孔缺口件在4种疲劳载荷作用下6种损伤模型的累积规律都为线性.以该结论为基础可估算缺口件的疲劳寿命.To solve the problem of inaccurate evaluation on fatigue life of notched specimen for the traditional fatigue method, the concept of fatigue damage accumulation is introduced. The stress and strain responses of notched nodes were calculated using finite element method under four different loading conditions. The components of stress and strain along an arbitrary plane for notched nodes were derived based on the transform between old and new systems. Six damage parameters were studied and the variation of them with the plane position was calculated. The maximum value for each damage parameter was then determined. To investigate the rule of damage parameter accumulation, the maximal damage accumulation was calculated for each cycle, and relationship between the cycle number and the damage accumulation parameter was then obtained. It is shown that the fatigue damage accumulation rules of notched specimen for six damage models under four different cycling loads are all linear, and then the fatigue life of notched specimen can be predicted.

关 键 词：缺口件 疲劳寿命估算 损伤参量 损伤累积规律 

分 类 号：O346.2[理学—固体力学]