摘要
首先,以损伤力学作为理论基础,建立以扭角与材料常数为参量的转矩与时间的函数关系,即转矩与时间的理论曲线以及转矩门槛值与扭转切应力门槛值的关系式。此函数关系表明:对一定材料,所给定的扭角愈大,则转矩随时间的衰减速度也愈快。为了缩短试验研究的周期,在以上理论分析基础上,提出加速试验方案。在大扭角(远大于贮存扭角)情况下进行扭转试验,得到转矩的门槛值,并确定扭转切应变门槛值。然后,利用大扭角情况下得到的切应变门槛值,根据损伤力学的理论公式间接推断出小扭角(即给定扭角)情况下转矩门槛值,从而预估扭杆弹簧在给定扭角下储存给定时间后的剩余转矩值。最后,为了验证扭杆刚度衰减研究的损伤力学理论,在中扭角(大于贮存扭角)情况下进行扭转试验,也得到转矩的门槛值,并间接推断出小扭角情况下转矩门槛值。两种情况下的结果吻合较好,也证明了上述方法的正确性。
Firstly, based on the theory of damage mechanics, the function of the relation between torque and time is given by twisting angle and material constants, which is also the theoretical curve between torque and time and the relation between the torque threshold and the shear stress threshold. The function shows that the torque attenuation is more rapid under larger twisting angle. Therefore, in order to shorten the experimental period, the accelerating experiment method is put forward based on the above theoretical analysis. The torque threshold is obtained by the experiment under large twisting angle, which is much larger than reserved twisting angle. Then the shear strain threshold is determined accordingly. Afterwards, the torque threshold under small twisting angle, which is also the reserved twisting angle, is deduced indirectly, and this torque threshold can be used to determine the residual torque according to given time. Besides, in order to prove the correctness of the above theory and the method in this article, the experiment under middle twisting angle, which is larger than reserved twisting angle, is carried out to obtain the shear strain threshold accordingly and the torque threshold under small twisting angle is also deduced. The two thresholds determined by the above two kinds of experiments are well accordant, which greatly proves the correcmess of the above theory and the method.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2007年第7期44-48,共5页
Journal of Mechanical Engineering
关键词
转矩门槛值
损伤力学
加速试验
Torque threshold Mechanics of damage Accelerating experiment
