Computer Modelling of Creep Damage in Components with Variable Metallurgical Structure
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Inhomogeneities in stress distribution in structural components usually arise from changes in section. However, stress concentrations can occur in components of uniform section if there are differences in mechanical properties from point to point in the body. Differences in elastic moduli can give inhomogeneous stresses although, since variations in elastic constants with metallurgical structure are not large, such effects are generally small. When creep deformation can occur, the situation is different. A geometric stress concentration will often be dissipated by creep if sufficient ductility is available but those stress concentrations due to material properties can be intensified. Metallurgical structures can have creep properties which are so different that as creep loads are added to the external loadings in service, stress intensification can occur where restraints are imposed due to relatively slow deformation rates. Thus metallurgical notches can develop and may lead to premature failure.
KeywordsEffective Stress Heat Affected Zone Maximum Principal Stress Weld Interface Rupture Life
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