Mathematical Modeling of Creep Induced byMachining Residual Stresses

Dimensional stability of materials is of critical importance in fabricating precision components such as those used in optical systems. An important source of dimensional instability is residual stresses introduced into the surface of parts during machining. In this paper, a creep model is developed and used to describe how these surface stresses affect the overall geometry of a component as it creeps over time and temperature. The model can be used for two purposes: (1) to predict long term storage effects on part geometry for purposes of assessing part reliability, and (2) to design short term, moderate temperature stress relief treatments for components. The model is verified by applying it to components manufactured from aluminum alloy 6061-T6.