Physical multi-factor driven nonlinear superposition for machining deformation reconstruction

In recent years, the machining deformation of titanium alloy frame parts has become a major research issue in the field of aviation manufacture. Through the generation mechanism, the machining deformation is divided into three parts including bulk residual stresses, cutting forces and other uncertain factors induced deformation. The nonlinearity of physical multi-factor machining deformation is revealed by the comparison between the purely linear addition and coupling superposition. A novel nonlinear superposition model is proposed for machining deformation reconstruction in this work. With the experimental values as simulation inputs, the physical multifactor driven simulation is developed to solve the nonlinear parameters of machining components in the superposition model. The posterior information embedded in the measurement is utilized to calibrate the nonlinear superposition model in the form of binary polynomials with five orders. The nonlinear superposition model is validated through four series of machining tasks, with the average model accuracy at 91.09%. To quantitively evaluate the proportion share of deformation components, a dimensionless equivalent machining deformation ratio is developed by the integral operation of the established nonlinear model. The results indicate that the bulk residual stresses, cutting forces and other uncertain factors account for percentages of 24.72%, 65.07%, and 13.21% (the ratio among them around 2:5:1). The proposed nonlinear superposition model and dimensionless equivalent ratio in this work display the potential application prospects in the field of machining deformation prediction and control.