Modeling and Simulation of Shrinkage During the Picture Tube Panel Forming Process

The accurate prediction of residual stresses and shrinkage of the formed picture tube panel is important to achieve high quality and precision of the final product. In this paper, the numerical simulation of shrinkage of molded panels was carried out in consideration of the residual stresses accumulated during both the packing and free-to-contract stages. For residual stress analysis, a thermorheologically simple viscoelastic material model was introduced to consider the stresses relaxation effect and to describe the mechanical behavior according to the temperature change. The deformation of molded parts induced by the residual stresses was calculated based on the theory of shells, represented as an assembly of flat elements formed by combining the constant strain and the discrete Kirchhoff triangular elements. The simulation results of the developed program were side verified by comparing the dimensional accuracy of the panels produced by the molds, which compensated for a uniform part shrinkage or the predicted ununiform part shrinkage.