焊接结构多轴疲劳寿命预测结构应力法  

Structural stress approach for multiaxial fatigue life estimation of welded structures

作　　者：刘刚[1] 刘英芳[1] 黄一[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：《船舶力学》2014年第10期1220-1227,共8页Journal of Ship Mechanics

基　　金：国家自然科学基金项目(51179027;51221961);国家973计划项目(2011CB013704)

摘　　要：海洋工程焊接结构形式复杂且遭受随机波浪载荷作用,焊接接头多数处于多轴疲劳状态,而目前工程上主要采用基于单轴疲劳理论和试验的方法预测结构的疲劳寿命。为了提高焊接结构疲劳寿命预测的准确性,文章提出了一种评估焊接接头疲劳强度的新型结构应力法,并与临界面理论相结合,能够用于实际焊接结构的多轴疲劳寿命预测。通过对国际上已公开发表的疲劳试验数据进行有限元分析,证明了文中提出的结构应力法比传统的热点应力法具有更高的精度,以及该方法应用于焊接结构多轴疲劳寿命预测的可行性。最后,应用该方法对一个T型管节点进行了多轴疲劳寿命计算。Welded structures in ocean engineering are complex and subjected to random wave loads, which results in multiaxial fatigue state for most welded joints. However, methods used to estimate fatigue life of welded structures at present are mainly based on uniaxial fatigue theory and tests. To improve accuracy of fatigue life estimation for welded joints, a new structural stress approach is proposed. In combination with the critical plane theory, the new structural stress approach can be used to estimate the multiaxial fatigue life for real welded structures. By numerically analyzing a series of published fatigue data, the new struc-tural stress approach proves more accurate than the traditional hot spot stress approach, and feasible for the multiaxial fatigue life estimation. Finally, the proposed approach is used to calculate the multiaxial fatigue life of a tubular T-joint.

关 键 词：结构应力 多轴疲劳寿命 焊接接头 临界面理论 

分 类 号：O346.2[理学—固体力学]