Modelling the creep in a welded plate using a three-director Cosserat model

Cracking in ferritic weldments at high temperatures often occurs outside the weld in the narrow type IV region (which is sometimes called the low-temperature heat affected zone). In this paper a mathematical model is developed for the steady-state creep of a flat plate of constant thickness, under uniaxial end loading. The model is based on the Cosserat theory of plates and a multi-axial version of Norton's law and includes three directors. Results for the steady-state creep strain-rate are calculated for values of the material parameters based on a ferritic material which is susceptible to cracking in the type IV region