整个螺栓结合部的法向连接动刚度及试验验证

根据一种修正双变量Weierstrass-Mandelbrot函数,获得了整个螺栓结合部法向连接动刚度的解析解.采用等效表面的结构函数,给出了识别结合部分形维数、分形粗糙度的理论与试验方法.以风电机组五面体加工中心上的横梁-导轨结合部为对象,以测试试件的试验模态为基准,按照相似振型相关分析和固有频率定量比较的原则,对整个螺栓结合部法向连接动刚度的理论解进行了验证,结果表明,理论模型的振型与试验振型相吻合,理论的固有频率与试验的相对误差在-4.3％～5.1％之间.

Analysis and Validation on Normal Connection Dynamic Stiffness of Bolted Joint Interface Ensemble

The analytic expression for the normal connection dynamic stiffness of whole bolted joint interface was deduced using a modified two-variable Weierstrass-Mandelbrot function.Theoretical and experimental methods to identify the fractal dimension and fractal roughness of the joint interface were presented with the structure function for the equivalent surface.A beam-rail joint interface was selected as a research object at the pentahedral machining center of a wind turbine,and experimental modes of test specimen were viewed as reference.The theoretical solution to the normal connection dynamic stiffness of the bolted joint interface ensemble was validated by the correlative analysis of analogous vibration shape and the quantitative comparison of natural frequencies.The theoretical vibration shapes agree with the experimental ones.The relative deviation of the theoretical natural frequencies from the experimental results is from-4.3 % to 5.1 %.