航空发动机薄壁叶片激光等离子体冲击超高应变率变形机理

项目名称： 航空发动机薄壁叶片激光等离子体冲击超高应变率变形机理

项目编号： No.51205406

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 机械工程学科

项目作者： 何卫锋

作者单位： 中国人民解放军空军工程大学

项目金额： 26万元

中文摘要： 叶片疲劳断裂是航空发动机故障的主要形式之一，严重影响其安全可靠性。激光诱导等离子体冲击波对金属材料超高应变率强化，是解决构件疲劳断裂故障的重要措施，成为20世纪90年代以来国内外研究热点。但对于高推重比航空发动机薄壁叶片，由于缺乏对冲击波复杂耦合作用下材料超高应变率动态响应和薄壁叶片中弹塑性应力波传播规律的深刻理解，无法实现叶片变形控制和残余应力场优化，导致其抗疲劳性能下降。本项目以钛合金薄壁叶片为研究对象，构建冲击波作用下钛合金超高应变率本构模型，以探究冲击波在薄壁叶片中的传播规律和叶片变形机理为核心，采用理论研究、实验测试和数值仿真相结合的方法，解决激光等离子体冲击载荷下超高应变率本构模型的不足和动态力学性能参数难以直接获取等问题，实现薄壁叶片变形控制和残余应力场优化，为研究冲击载荷条件下薄壁结构的动力学响应奠定理论基础，为激光冲击强化在薄壁叶片中的应用提供技术支持。

中文关键词： 纳秒脉冲激光；冲击波；本构模型；参数辨识；变形机理

英文摘要： Blade fatigue fracture is one of the major forms of the aeroengine heart failures in aviation, and it has seriously impacted the aeroengine's safety and reliability. In order to solve the problem, the intensification theory and technology of inducing plasma shockwave by laser became a hotly researched topic at home and abroad from 1990s. As to the thin blade of high-powered aeroengine,the shockwave reflects at the two sides of the blade and form complicated coupling of multiple waves, which will lead to the deformation of the blade and asymmetrical redisual stress, which can't meet the use requirement and even result in its performance degradation. In this project，taken the thin titanium alloy balde of a certain kind aeroengine as the research material, a constitutive model with high strain rate under shockwave is established by experiments and simulation, and the material's constitutive model parameters under high pressure and ultra high strain rate are confirmed by reverse and optimization methods.Moreover,the research results also include the shockwave propagation pattern,the distribution character of the residual stress field and deformation mechanism of thin blade.The project solves the problem of material's dynamic parameters acquisition under high pressure and high strain rate, and realizes the residual s

英文关键词： nanosecond pulsed laser；shock wave；constitutive model；parameter identification；deformation mechanism