Normal Contact Stiffness Fractal Geometric Model Based on the Gamma Distribution of Rough Joint Surface

Abstract

In this article, according to WenShuHua and Zhangxueniang fractal model, we point out the deficiency. Based on the fractal theory and Zhang, Wens contact stiffness fractal model, this paper puts forward Gamma distribution of rough joint surface normal contact stiffness. This paper considers micro convex body for ellipsoid, contact area for elliptic. This is slightly convex body for sphere hypothesis is more close to the actual situation. At the same time by using statistics theory, considering the contact ellipse long, short axis a and b are greater than zero, the assumption of a and b to two-dimensional Gamma distribution, it is more suitable for engineering practice.

Stiffness Calculation Method and Stiffness Characteristic Analysis of Bolted Connectors

“…Because the machined surface is not smooth and consists of a series of uneven peaks and valleys (as shown in Figure 2), forming a certain roughness, the contact of the two rough surfaces forms a joint surface. Many scholars have studied the stiffness of the joint surface: some studies are based on the fractal theory [17][18][19][20][21][22] from a micro perspective and some scholars have modeled the stiffness of the joint surface based on experiments. e stiffness characteristic formula is obtained by test [23][24][25][26].…”