喷丸残余应力对裂纹扩展疲劳寿命的影响  

Effect of shot peening residual stress on crack growth fatigue life

作　　者：王建明[1,2] 赵莉莉[1] 吕鹤婷 

机构地区：[1]山东大学机械工程学院,山东济南250061 [2]山东大学高效洁净机械制造教育部重点实验室,山东济南250061

出　　处：《哈尔滨工程大学学报》2016年第4期608-613,共6页Journal of Harbin Engineering University

基　　金：国家自然科学基金项目(51375267);山东省科技发展计划(2013GGX10303)

摘　　要：为了研究喷丸表面处理对试样疲劳寿命的影响,基于ABAQUS软件建立含喷丸残余应力场的四点弯曲试样有限元模型和考虑裂纹闭合效应的裂纹扩展疲劳寿命预测模型。基于该模型研究了不同应力比及不同喷丸工艺条件下的受喷与未喷试样的裂纹扩展疲劳寿命。结果表明,正应力比越大越不容易产生裂纹闭合从而寿命越短,不同应力比条件下喷丸试样的疲劳寿命均约为相同条件下未喷丸试样的2.5倍;单独喷丸强化对裂纹扩展疲劳寿命的提高作用高于喷丸成形与强化的联合作用。主要是由于喷丸强化产生的残余压应力在距离表层较近的范围大于成形与强化联合作用所产生的残余压应力,且该残余压应力对裂纹扩展疲劳寿命的提高起主导作用。通过预测结果与文献实验结果的对比,验证了本文所建模型的正确性及有效性。To determine the effects of shot peening on crack growth fatigue life, a four-point bending specimen finite element model with a shot peening residual stress field was established by using ABAQUS. In addition, a crack growth fatigue life prediction model considering the crack closure effect was developed. By comparing the predicted results with those in the literature, the accuracy of the model presented in this paper was verified. Based on the models , the crack growth fatigue life of specimens with and without shot peening residual stress under different stress ratios and different shot-peening methods was studied. The results show that crack growth fatigue life decreases with an increase in the positive stress ratio, and for different stress ratio under the same condition, the fatigue life of a specimen with shot peening residual stress is about 2.5 times that of a specimen without shot peening residual stress. Furthermore, subsurface residual stress plays a leading role in increasing crack growth fatigue life. The effect of shot peening in terms of improving crack growth fatigue life is better than that of the combination of forming and strengthening because the subsurface residual stress induced by the former is greater than that induced by the latter.

关 键 词：裂纹扩展 疲劳寿命 喷丸强化 残余应力 裂纹闭合 有限元法 

分 类 号：O346.2[理学—固体力学]