中文摘要：

以不同出厂年限的桑塔纳轿车等速万向传动中间轴为试验对象,试验研究了中间轴前四阶固有频率、不同截面处的表面硬度等典型机械特性随出厂年限的变化情况。研究结果表明：随着中间轴出厂年限的增加,其固有频率有所下降,且下降幅度较小;中间轴固有频率最高下降1.2%,前4阶固有频率下降幅度中高阶大于低阶,但下降率的变化没有规律;不同截面处的表面硬度略微变化,存在先上升后下降的趋势;根据中间轴固有频率和硬度的变化,可以初步推断出中间轴还有60%以上的剩余寿命,具有回收利用价值。

英文摘要：

Using constant velocity universal drive shaft of Santana Automobile with different service lives,mechanical characteristics such as natural frequency and hardness were investigated. The results show that natural frequency of drive shaft decreases slightly with the increase of service life. The maximum of reduction for natural frequency is1. 2%. The high-rank natural frequency decreases more obviously than the low-rank,but no regulation was found. Surface hardness of different cross-sections changes slightly,which shows a trend from rise to decline. According to the changes of natural frequency and hardness,it predicts that drive shafts have over 60% service life.