高频谐振疲劳机载荷测量误差建模分析及试验夹具优化设计  

Modeling Analysis of Load Measurement Errors and Optimal Design of Test Fixtures for High Frequency Resonant Fatigue Machines

作　　者：高红俐[1] 朱楷勇 龚澳 姜伟[1] GAO Hongli;ZHU Kaiyong;GONG Ao;JIANG Wei(Key Laboratory of Special Purpose Equipment and Advanced Manufacturing Technology,Ministry of Education&Zhejiang Province,Zhejiang University of Technology,Hangzhou,310014)

机构地区：[1]浙江工业大学特种装备制造与先进加工技术教育部/浙江省重点实验室

出　　处：《中国机械工程》2019年第22期2675-2682,共8页China Mechanical Engineering

基　　金：国家自然科学基金资助项目(51375445)

摘　　要：电磁谐振式疲劳裂纹扩展试验过程中,对动态载荷的高精度测量和控制是保证试验结果准确性和系统工作稳定性的重要前提,夹具作为夹持试件和传递载荷的重要机构,对其进行结构优化显得尤为重要。建立了紧凑拉伸(CT)试件连接刚度模型和三自由度有阻尼振动系统动力学模型,得到了动态载荷测量误差理论表达式;分析了夹具刚度对动态载荷测量误差的影响,设计了不同结构刚度的试件夹具,并通过有限元方法计算其刚度,得到了不同结构夹具对动态载荷测量误差的影响结果;实验验证了优化夹具设计的合理性。High precision measurement and control of dynamic forces in the electromagnetic resonance fatigue crack growth test processes were important premises to ensure the accuracy of test results and the stability of the system. Fixtures were the important mechanisms for clamping specimen and transferring force, so it is particularly important to optimize the fixture structures. A compact tensile specimen connection stiffness model and a three-degree-of-freedom with damping vibration system dynamical model were established, and the theoretical equation of dynamic force measurement errors was obtained. Influences of fixture stiffness on the dynamic force measurement errors were analyzed. Accordingly, different structure stiffness fixtures were designed, and the stiffness of the fixtures was calculated by the finite element method. The influence results of different structural fixtures on the dynamic force measurement errors were obtained. Rationality of the optimal fixture design was verified by the experiments.

关 键 词：动态载荷 高精度测量 疲劳裂纹扩展试验 接触刚度 夹具优化 电磁谐振 

分 类 号：TP394.1[自动化与计算机技术—计算机应用技术] TB534.3[自动化与计算机技术—计算机科学与技术]