柔性体建模及参振质量影响考证

Validation of Flex-Body Modelling and General Mass Influences

针对参振质量及其约束影响的模糊认识,讨论了参振质量的时空可变性与约束内力的力学属性.结合两个典型案例研究表明:参振质量是决定六连杆机构基频的主要因素之一,且呈现周期性变化规律.就超静定问题来讲,若变形协调性成为影响约束内力动荷效应的一个敏感因素,则会导致结构失效.高频参振质量会不断降低且形成了局部振动的敏感频响特征.因而整体结构刚度均匀性或变形协调性则是保证其振动疲劳安全的一项重要前提条件.

For vague recognitions of general mass and constraint influences, two standpoints were proposed clearly, i.e. the time and space variations of general mass and the mechanical attributes of constraints. The in- vestigations of two typical case studies show that the general mass is one of the main factors in determining the fundamental frequency of six-ink gear, which is presented to be varied periodically. For the static indeterminate problems, if the deformation compatibility becomes one of sensitive factors to influence the dynamical load effects of constraint inner forces, the structure failures will occur constantly. The general mass of high-frequency vibrations will decrease, so that the sensitive responds of local vibrations can be caused easily. The stiffness homogeneity or deformation compatibility of full structures is then the important prerequisite to ensuring the vi- bration fatigue safety.