基于耦合细观损伤模型的旋扭低应力精密下料机理研究  

Research on rotary-torsion low-stress precision blanking mechanismbased on coupled meso-damage model

作　　者：李鹏伟 王哲[1] 于正洋 Li Pengwei;Wang Zhe;Yu Zhengyang(School of Aeronautical Manufacturing Engineering,Xi'an Aeronautical Polytechnic Institute,Xi'an 710089,China;School of Safety Science and Engineering,Xi'an University of Science and Technology,Xi'an 710054,China)

机构地区：[1]西安航空职业技术学院航空制造工程学院,陕西西安710089 [2]西安科技大学安全科学与工程学院,陕西西安710054

出　　处：《锻压技术》2024年第6期260-268,共9页Forging & Stamping Technology

基　　金：陕西省教育厅科学研究计划项目(22JK0428)。

摘　　要：旋扭低应力精密下料具有低耗、高效、质优等特性,精准的损伤预测可为旋扭低应力精密下料近净成形工艺参数的选取奠定理论基础,因此,基于细观损伤力学理论与等效临界断裂应变-应力三轴度理论的耦合细观损伤模型被应用于预测精密下料时的损伤演化。采用显微分析法、理论解析法及逆向求解法相结合的方法标定了304不锈钢的耦合细观损伤模型参数,对比分析了耦合细观损伤模型与单轴拉伸试验所获得的载荷-位移曲线,验证了所构建的耦合细观损伤模型及模型参数的合理性。利用数值化分析了不同加载速度下旋扭低应力精密下料的损伤演化过程,并开展了精密下料试验以验证数值模拟结果的正确性。结果表明:依托端面平整度和下料时间的下料质量综合评价指标,当加载速度为3 mm·s^(-1)时能够获得合理的下料效率及坯料端面精度。耦合细观损伤模型可应用于旋扭低应力精密下料近净成形工艺的损伤演化预测,为后续精密下料工艺参数的合理选取提供了理论支撑。Rotary-torsion low-stress precision blanking has the characteristics of low consumption,high efficiency and high quality,and accurate damage prediction can lay a theoretical foundation for the selection of near-net shape forming process parameters for rotary-torsion low-stress precision blanking.Therefore,a coupled meso-damage model based on meso-damage mechanical theory and equivalent critical fracture strain-stress triaxiality theory was applied to predict the damage evolution during precision blanking,and the coupled meso-damage model parameters of 304 stainless steel were calibrated by the methods of microscopic analysis,theoretical analysis and reverse solution.Then,by comparing and analyzing the load-displacement curves obtained by coupled meso-damage model and uniaxial tensile experiment,the rationality of the coupled meso-damage model and its parameters was verified.Furthermore,the damage evolution process of rotary-tor-sion low-stress precision blanking under different loading speeds was numerically analyzed,and the precision blanking experiments were conducted to verify the correctness of numerical simulation results.The results show that the reasonable blanking efficiency and cross-sec-tion accuracy of blank can be obtained when the loading speed is 3 mm s^(-1) depending on the comprehensive evaluation index of blanking quality as cross-section flatness and blanking time.Thus,the coupled meso-damage model can be used to predict the damage evolution of near-net shape forming method for rotary-torsion low-stress precision blanking,which provides the theoretical support for the reasonable se-lection of subsequent precision blanking process parameters.

关 键 词：旋扭低应力 精密下料 耦合细观损伤模型 损伤演化 304不锈钢 

分 类 号：TG316[金属学及工艺—金属压力加工]