Welding analysis of a welded motorcycle rim
The problem and the task formulation
A rim of the car is welded of two parts: the rim proper and the braking pad. The client met with a problem – during fatigue testing with the nominal torque it turned out that after six hours of operation fatigue cracks appeared on the external surface of the rim within the welded unit. Calculations made without consideration of impact exerted by welding on the part structure could not explain the cause of the rim breakage, since rated stress within the welded joint did not reach the yield limit.
To explain the results of full-scale testing it was required to perform temperature and phase calculations for the welding, thereby allowing identification of the residual stress in the welded part material.
The client provided to us, via Internet, sketches of the welded parts and a general characterization of the load on the wheel rim. 3D modeling was made using Unigraphics Software by EDS Company.
We created the rated 3D model based on the three-dimensional model of the trim and pad assembly. Welding simulation was carried out using SYSWELD Software by ESI Group Company. To simulate the welding process we predetermined operational conditions, and to make strength calculations we simulated sealing conditions. All procedures were performed under CAD/CAE/PDM.
Our calculations demonstrated that welding did cause significant elastic deformations in the joint area. Application of the nominal torque finally damaged the elastic deformation area since deformed sections were under long-time impact. Without considering welding processes during calculations it was impossible to identify the breakage cause.
Our calculations of welded joints allowed the client to identify the cause of breakage and take into consideration tensions, stress and phase transformations in the welded joint during the design of the unit.
Cooperation with our company helped the client save significant resources: only one verification test was made that completely confirmed results of our calculations.
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