Coupled Thermomechanical Strain Life FEA for Large Format Gigacast Tray Molds
Coupled thermomechanical strain-life FEA predicts thermal checking and insert fatigue life in gigacast tray molds using non-linear elastoplastic plasticity models.
Elevated Temperature Creep
Meaning
Permanent deformation of a solid material occurs under a constant load when the temperature exceeds a specific fraction of its melting point. Studying elevated temperature creep allows engineers to predict the long term stability of battery busbars and fasteners under thermal load. The strain rate increases as the thermal energy makes atomic movement through the crystal lattice easier.
This phenomenon can lead to the loosening of mechanical joints which increases electrical resistance in the battery circuit.
Deformation Mechanism
Atomic diffusion and grain boundary sliding are the primary drivers of this slow stretching. In the context of elevated temperature creep the metal does not fail immediately but gradually loses its shape. This behavior is dangerous in bolted connections where the clamping force might diminish over time and lead to overheating.
Material Selection
Alloys are chosen based on their resistance to these slow changes in dimension. Engineers analyze elevated temperature creep data to ensure that the chosen aluminum or copper grade maintains electrical contact pressure. High performance alloys often include specific alloying elements that pin grain boundaries to prevent sliding.
Structural Integrity
Failure occurs when the cumulative strain leads to necking or internal void formation. Monitoring for elevated temperature creep is a standard part of life cycle testing for components that operate near the limits of their thermal window. If the deformation exceeds design tolerances the part may short circuit or lose its structural support.