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Residual stresses are tensions or compressions that exist in the bulk of a material without applying an external load. In a casting process, while cooling, residual stresses are induced due to temperature gradients across the whole casting, mechanical constraints given by the mold during the shrinkage of the metal and volumetric change and transformation plasticity related to the solid-state phase transformation. Hence, residual stresses are a function of the shape of the casting and the cooling rate of the casting process. Compressive residual stresses are desirable in a component as they improve the fatigue life and reduce the stress corrosion cracking tendency since they also offer resistance to crack propagation. Since the residual stresses can increase or decrease the fatigue life of a component, an interest on its consideration during the design process has grown in the industry of casted parts.

  For the analysis, a coupled thermo-mechanical analysis is required.. First, a thermal analysis is carried out where the casting is cooled down from a super-heated temperature to room temperature. The thermal history obtained, is then used as an external force to calculate the residual stresses by means of a quasi-static mechanical analysis. 

The objective is to study residual stress formation in a truck wheel hub as it is been casted. For the analysis, first the hub is modeled and meshed (Pre-Processing). The mesh file is then imported to a solver and different material property required for solving has to be specified. The necessary boundary conditions should also be given. The solving is then carried out and various results are then viewed in a Post-Processor.


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