低幅载荷对汽车前轴疲劳寿命影响的试验研究

为了探讨基于载荷特性的汽车结构件轻量化设计理论与方法，采用汽车前轴实物物理试验的方法，比较系统地研究某汽车前轴在低幅交变载荷作用下结构疲劳寿命的变化趋势，发现在低于疲劳极限的低幅应力区内存在一个强化载荷区。用强化载荷区内的不同载荷对前轴进行预锻炼，前轴的疲劳寿命有不同程度的提高。既使在高低载荷交替作用的条件下，低载强化效果依然存在。结构的寿命由强度衰减速率和强度提高速率共同决定，而不是仅由损伤决定。

STUDYING THE EFFECT OF LOW AMPLITUDE LOADING ON FATIGUE LIFE OF TRUCK FRONT AXLE

Experimental studies were carried out on real front axle to investigate the influence of low amplitude pre loading on structure life in order to explore new theory of weight reduction based on servicing loads. It is found that a strengthening area exists below the fatigue limit. Fatigue lives of front axles in some extent increase with pre loading within this area. Strengthening effect also appears under alternative high amplitude and low amplitude block loads. It is concluded that the fatigue life of structures depends on both rates of strength degradation and strengthening, not on fatigue damage alone.