冷挤压孔的光塑性力学分析

Mechanical Analysis of Cold worked Hole by Photo plastics

为了使冷挤压孔真正起到抗疲劳增寿效果 ,有效控制孔表面残余应力大小及其分布是至关重要的。该文采用光塑性力学分析法 ,利用模型材料与原型材料的相似性 ,研究带衬套挤压和不带衬套挤压的 2种情况下孔边的应力、应变分布规律。结论如下 :采用光塑性力学分析法可真实地再现冷挤压孔过程中的应力、应变情况 ;无衬套挤压时 ,孔边在x和y2个方向的应力应变非常接近 ,而带衬套挤压中 ,衬套开口处产生的应力应变最大 ,与之相对应的 1 80°附近应力应变最小 ;在拉伸状态下 ,将衬套开口置于主载荷方向 。

In order to strengthen anti fatigue of cold worked hole, it is necessary to control the magnitude and distribution of the surface residual stress and strain. A photoplastic mechanical analysis method is used to study the strain and stress distribution with or without split sleeve,based on similarity between model and real object.It concluded that photoplastic mechanical analysis can really measure the stress and strain distribution during the process of cold compression. The stress and strain without solit sleeve are much similar in both x and y typical directions whereas it is different in case of with split sleeve. The stress and strain amount to the maximum in open sleeve,and their minimum reached under 180 ℃. Under extension, the cracks caused by compression will be of no harm to the anti fatigue life of the hole if the open split sleeve is placed in the direction of the main load.