Research On Weld Fatigue Life Of A Car Door

Auto industry has become the pillar industry of national economy in our country. Since 2013, our country automobile production has been three consecutive years more than 20 million vehicles, and with global record highs in 2015 the world for seven consecutive years. In such a powerful market environment, competition is indispensable, and for a car is about to hit the road, the body strength and fatigue durability problems cannot be ignored.Based on an independent brand automobile door early cracking problems, studies factors influencing the door of the influence of the weld fatigue strength. Because of the many factors that affect the fatigue life of welded structure, this paper focuses on the three factors, including welding way(manual welding or robot welding), welding method(CO2 welding of carbon steel wire or CMT welding of silicon bronze wire) and the weld length(12 mm or 20 mm).The project team approved on the basis of both experimental scheme, to promote the project in two steps. As a first step, to understand the specified in certain parts of a car door, the door "on- off" in the process of circulation strain characteristics of the physical doors around the weld position in fatigue durability experiments to analyze the dynamic strain testing. According to the test results, combined with CAE simulation analysis, basic mastered the dynamic strain of the perimeter of the weld position of waveform characteristics.On the car door weld fatigue damage problem, weld specimen in the experiments, the research of weld fatigue life and the main technological factors of relevance. The experiment according to the welding method, welding material, weld length of experiment research, respectively. According to the different conditions of study on fatigue characteristic test for welding parts.Finally combining with field investigation, field and fatigue durability test and theoretical analysis, put forward the corresponding improvement suggestions to improve the fatigue life of welding seam door from the four aspects such as welding way, welding method, welding seam length,, etc.