结构疲劳长裂纹扩展速率新模型研究  

Research on New Model of Long Fatigue Crack Propagation Rates for Structures

作　　者：刘建涛[1] 杜平安[1] 黄明镜[2] 周晴[1] 

机构地区：[1]电子科技大学机械电子工程学院,成都610054 [2]中国燃气涡轮研究院,四川江油621703

出　　处：《应用数学和力学》2009年第5期538-546,共9页Applied Mathematics and Mechanics

基　　金：“十一五”总装预先研究基金资助项目(YG060101C)

摘　　要：比较现有疲劳长裂纹扩展速率模型的特点和不足,基于裂纹扩展钝化复锐理论推导,提出了广义钝化复锐疲劳长裂纹扩展速率模型(GPLFCPRM),并推导获得了疲劳长裂纹扩展速率模型通项.该模型克服了现有疲劳长裂纹扩展速率模型的缺点,能有效地描述自门槛值到断裂点全过程的裂纹扩展规律,具有明确的物理含义,且可反映材料的强度特性、断裂特性和热处理状态等因素对疲劳裂纹扩展速率的影响.通过LZ50钢、A533-B、AlZnMgCu0.5和0.5Cr0.5Mo0.25V钢疲劳裂纹扩展速率试验,结果反映该模型与试验结果十分吻合,且具有更广的通用性和应用推广价值.By comparison of the characteristics of existing models for long fatigue crack propagation rates,a new model called generalized passivation-lancet model for long fatigue crack propagation rates （GPLFCPR） and the general formula for characterizing the process of crack growth rates were put forward basedon the deduction of passivation-lancet theory. The GPLFCPR model overcomes the disadvantages of the existing models and could describe the rules of whole fatigue crack growth process from the cracking threshold to the critical fracturing point effectively with explicit physical meaning and also reflects the influence of material characteristics,such as strength parameters, fracture parameters and heat treatment, etc. Experimental results, testing with LZS0 stell, AlZnMgCu 0.5, 0.5Cr 0.5Mo 0.25V steel and so on, are used to verify the new model, which show great consistency. The GPLFCPR model owns much value for theoretical research and practical applications.

关 键 词：长疲劳裂纹 门槛值 循环应力比 断裂韧度 扩展模型 

分 类 号：O346.2[理学—固体力学] TB114.3[理学—力学]