Thermomechanical Fatigue Analysis Based on Continuum Mechanics

Abstract

Time varying cyclic loads produce failure of structural parts for values of stress lower than those obtained in static tests.
This phenomenon is called fatigue and its numerical analysis is complex but of crucial importance for most engineering
fields (mechanical, aeronautical, etc.).
In this work a thermo-mechanical constitutive model which allows to simulate thermal fatigue is presented. This model
is based on the mechanics of the continuous medium and allows to treat coupled phenomena such as fatigue with
damage, plasticity, viscosity and temperature in a unified way. The formulation based on the theories of damage and
plasticity is developed and the necessary modifications in order to include the fatigue phenomena into these theories are
outlined. Finally, the performance of the proposed model is shown via the analysis of an industrial test case for diecasting
applications.