Analytical modeling of residual stress and the induced deflection of a milled thin plate

Predictions of residual stress-induced deformations on thin aerospace parts are still among the most challenging and relevant problems in engineering applications. In this paper, a new methodology based on analytical modeling of machining mechanics is introduced in order to predict thin plate deflection induced by residual stresses given material attributes, process configurations, and parameters. The model uses an elasto-plastic constitutive behavior algorithm to predict the plastic stress, strain, and thus residual stresses. A relaxation procedure is applied upon residual stresses in order to quantify the elastic deflection when the plate is unloaded from cutting forces. Experimental validations are presented on multi-pass milling of aerospace grade aluminum alloy Al7050-T7451. The newly developed analytical model shows promise to predict the residual stresses and the thin plate deflection profile under various cutting conditions.