考虑应变均值影响的天然橡胶隔振元件疲劳寿命预测

Fatigue life prediction for a natural rubber anti-vibration component with mean strain effect

对橡胶试柱进行单轴疲劳试验,分析了应变幅值一定时,应变均值对疲劳寿命的影响。以哑铃型天然橡胶试柱为研究对象,通过有限元计算分析,得到了加载位移与橡胶试柱危险位置处最大主应变的关系。构建了应变均值函数,以应变比R=0时的ε-N曲线为基准疲劳寿命曲线,建立了不同应变均值和幅值下的天然橡胶隔振元件的疲劳寿命预测模型。使用该模型预测得到的哑铃型天然橡胶试柱疲劳寿命与试验疲劳寿命具有较好相关性。提出的天然橡胶元件的疲劳寿命预测模型,可用于建立天然橡胶材料的疲劳寿命数据库。

Uniaxial fatigue tests for a rubber specimen were conducted, and mean strain effect on fatigue life under constant strain amplitude was analyzed. Taking a dumbbell natural rubber specimen as a study object, the relationship between the loading displacement and the maximum principal strain of the rubber specimen at a critical position was determined with finite element analysis （FEA）. A mean strain function was constructed, and a fatigue life prediction model under different strain mean values and amplitudes was established based on the 8-N curve of the natural rubber with 0 strain ratio. The fatigue life of the dumbbell natural rubber specimen predicted with the model agreed well with the tested one. The fatigue life prediction model for a natural rubber component peoposed here was helpful for establishing fatigue life database of natural rubber materials.