集成铸造数值模拟的车轮疲劳分析

弯曲疲劳寿命是汽车车轮重要的性能指标，目前其预测方法仍局限于传统的名义应力法或局部应力应变法，没有考虑微观组织和铸造缺陷对疲劳寿命的影响，预测铝合金车轮在低应力水平下的高周疲劳寿命时与实际情况存在相当差距。基于小裂纹扩展理论，建立低压铸造铝合金A356-T6车轮的以二次枝晶臂间距、针孔尺寸为参数的疲劳寿命预测模型。实现铸造模拟、有限元分析与疲劳分析的集成，初步建立起综合铸造过程、铸造缺陷以及相关下游制造工艺对车轮力学性能影响的平台。以某型车轮为例，采用该方法预测其弯曲疲劳寿命，试验验证预测结果比Simth-Waston-Topper方法更为准确。

Integrating Casting Simulation into Automotive Wheel Fatigue Analysis

Bending test is the most important performance test of automotive wheel. At present, the fatigue life prediction still based on nominal stress approach or local stress-strain approach. The effect of microstructure and casting defects has not been considered in presently used approaches, there is a considerable difference between prediction results and real practice when these approaches are used to predict the high-cycle fatigue life of the aluminum alloy automotive wheels under low stress level. A fatigue life prediction model concerning secondary dendrite arm spacing and casting defect is built based on small fatigue crack propagation theory. Casting simulation and finite element analysis are integrated into fatigue analysis. An integrated platform to predict wheel mechanical performance that includes casting process, related casting defect and downstream manufacturing process is constructed primarily. The bending fatigue life of a certain type of wheel is predicted by using this model, and the experiment validates that the result is more accurate than Simth-Waston-Topper method.