Fundamental Study on Effect of Fabrication Tolerance on Slip Strength of High Strength Bolted Friction Type Joint with Thick Plates

This study focuses on fabrication tolerance of high strength bolted friction type joint. Many researches and studies have evaluated the effect of the tolerance of the joint to its strength. However, this paper especially focuses on long joints with extremely thick plates (75 mm) that contain many bolts (12 bolts) in a line. Past experimental and FEM analytical results have been investigated, which provides statistical characteristics of fabrication variations related to strength of joint.

The characteristic value obtained from the investigation shows that the variation of the thickness of coating (inorganic zing-rich paint) hardly affects the slip strength of the joint. Furthermore, the influence of the variations is evaluated based on the FEM analysis considering the statistical values obtained from the investigation. The results indicate some variations strongly affect to the slip strength. This paper deals with the joints which have a high slip/yield strength ratio and compares the results among the long/not-long joins. The results of the FEM analysis show that the variations of Young's modulus and yield point of the plates, friction coefficient of connected surfaces and pre- load of the bolts significantly affect the slip strength of long joints.