Improvement of Fatigue Life of Welding Structure by Epoxy Resin Coating

Abstract

The break-down welded structure is usually caused by fatigue fracture, starting from the toe of weld. This happens at the welded portion of truck chassis frame and Rear Axle Case. To improve their fatigue life, the following measures are usually taken: grinding, remelting, shot blast and shot peaning. However, these measures have some problems from the viewpoint of working conditions.
It is known that crack propagation rate is lesser in vaccum than in air. It is also considered that this fatigue life improvement is larger when stress consentration factor is larger. Epoxy resin may be used to examine this phenomenon by coating it on the welded portion, but the coated resin also affects the deformation of crack generation area. So, the effect of epoxy resin coating on fatigue fracture strength was investigated in this paper.