防振橡胶材料多轴疲劳损伤机理及其寿命预测方法研究

Rubber isolators, which are made of metal and rubber materials to isolate or reduce vibration and shock, are widely used in many areas, such as automotive industries, national defenses and constructions. However, currently automotive manufacturers rely mainly on their own trial-error based experience for the fatigue-proof design, for the lack of effective methods to reveal the fatigue damage mechanism and to evaluate the fatigue life for rubber materials... In this project, fatigue characteristics of rubber materials under multiaxial loads are to be investigated numerically and experimentally based on the theory of continuum damage mechanics and fatigue experiments in the following ways: (1) Fatigue experiments for capturing fatigue damage and fatigue life of rubber materials used for rubber isolators under multiaxial loads will be carried out, so as to reveal the damage mechanism of fatigue; (2) A visco-hyperelastic model for characterizing the constitutive behaviors of rubber under cyclic loads is to be established, so as to construct more precise model for evaluating the multiaxial fatigue life of rubber materials. In the visco-hyperelastic model, several types of nonlinearities including Mullins effect ( Strain-induced stress softening after a primary load), continuum stress-softening and permanent set in rubber are incorporated... The objective of this research is to expand and update the metrologies and theories for fatigue-proof design of rubber isolators, so as to improve the fatigue life of rubber components for automotive manufacturers. It is expected that this project has important scientific significance and application value.

防振橡胶是指一类用于防止或缓冲振动和冲击传递的、由金属和防振橡胶材料复合而成的弹性－阻尼元件，广泛应用于汽车工业、国防、建筑等领域。但是由于对防振橡胶材料的疲劳损伤机理及多轴疲劳特性分析方法的欠缺，其抗疲劳性能的实现往往靠反复设计、制造和大量的试验才可能达到。项目拟将基于连续损伤力学理论和疲劳试验方法研究防振橡胶材料的多轴疲劳损伤机理；构建考虑疲劳载荷作用下防振橡胶材料多种非线性特性（Mullins效应、循环应力软化、永久变形）的超弹性－粘弹性本构模型，以建立更为精准的多轴疲劳损伤模型。项目的最终目标是完善和发展防振橡胶的抗疲劳设计理论与方法，提高我国车用防振橡胶的疲劳寿命和产品综合性能，具有重要的科学意义和应用价值。

防振橡胶是指一类用于防止或缓冲振动和冲击传递的、由金属和防振橡胶材料复合而成的弹性－阻尼元件，广泛应用于汽车工业、国防、建筑等领域。但是由于对防振橡胶材料的疲劳损伤机理及多轴疲劳特性分析方法的欠缺，其抗疲劳性能的实现往往靠反复设计、制造和大量的试验才可能达到。项目开展常用汽车防振橡胶材料疲劳裂纹扩展试验，探究橡胶疲劳裂纹扩展规律；研究在不同橡胶本构模型下复杂结构橡胶部件多轴疲劳寿命的计算方法；以汽车悬架控制臂为对象，研究汽车隔振零部件抗疲劳设计的基本方法；为获得不同服役环境下橡胶疲劳载荷，研究冷凝器散热器风扇模块中橡胶悬置系统的位移和载荷计算方法。研究结果表明，橡胶疲劳裂纹扩展规律可基于幂法则进行模型建立；结合开裂能密度疲劳损伤参量和材料的疲劳裂纹扩展特性，可用来预测橡胶隔振器的多轴疲劳寿命；基于疲劳损伤理论，对汽车结构进行寿命预测，通过薄弱部位结构增强，可显著提高部件的疲劳寿命；计算的橡胶悬置位移和悬置受力能提供冷凝器散热器风扇模块的橡胶疲劳载荷范围。本项目的研究能完善和发展防振橡胶的抗疲劳设计理论与方法，提高我国车用防振橡胶的疲劳寿命和产品综合性能，具有重要的科学意义和应用价值。