摘要
分析原有场强法预测精度存在偏差的原因,在场强理论的基础上,重新定义疲劳损伤区域和权函数。新的损伤区域考虑了载荷幅值、缺口形状等因素的影响,能相对完整地考虑缺口局部材料对损伤的作用;权函数考虑了峰值点周围应力幅值、距离以及方向对损伤贡献程度的影响。通过对不同材料、不同结构形状缺口件的应力应变场分析,结果显示,改进的场强算法预测精度明显高于原有场强法,并显著地降低了有限元分析的网格要求。以改进的场强方法对比名义应力法和局部应力应变法,结果显示,其预测精度高于两种疲劳寿命方法,能较好地预测构件疲劳寿命。
The damage area and the weight function are redefined on the basis of analzing the reasons for low prediction accuracy of the original field intensity method. Considering the impact of load amplitude and gap shape etc, the new defination of damage area can completely reflects the surrounding material＇s influence on gap injury;The new defination of weight function takes into account the im- pact of magnitude, distance and direction of stress. Through the analysis of stress field of different materials and different structures, it is shown that the improved method predicts the fatigue life better and significantly reduces the finite element mesh requirements. Compared with the traditional nominal stress method and local stress-strain method, the improved field intensity method predicts the fatigue life better, and its accuracy is significantly better than that of the other two engineering methods.
出处
《济南大学学报（自然科学版）》
CAS
北大核心
2014年第6期439-445,共7页
Journal of University of Jinan(Science and Technology)
基金
国家重点基础研究发展计划(973计划)(2011CB013704)
关键词
疲劳损伤机制
损伤区域
权函数
场强力
疲劳寿命
damage mechanism
damage area
weight function
field stress intensity
fatigue life
