Failure Analysis of Fracture of Scraping Rod Joint of Car Wiper

A scraping rod joint of car wiper fractured after the test of continuous snow jam for 12 hours. Failure reasons of the scraping rod joint were analyzed through a set of tests of macroscopic examination, fracture analysis, chemical compositions analysis, hardness test and metallographic examination. The results show that the mechanical damage defects were found at the step of R salient which lied inside of the scraping rod joint, and the crack was initiated from the mechanical damage defects, along with the stress concentration of the step, so the one-time large stress fracture took place during the test of continuous snow jam.