抄録
The present paper explains the residual stress and deformation due to thermoviscoelastic behavior of materials and non-uniformity temperature in the cooling process during its molding.
The viscoelastic model including an element for thermal expansion is proposed in order to express the viscoelastic behavior of material with temperature change. Using this model, a qualitative prediction of the residual stress and deformation in cooled viscoelastic material is done.
Using the linear-viscoelastic theory, fundamental equations for the residual stress and deformation in a viscoelastic beam, where an unsteady and non-uniformity temperature distribution is assumed in the direction of depth, are shown. The theoretical values of residual stress and deformation in beams are calculated under various constraint and temperature conditions for two resins having different viscoelastic characteristics, i. e. epoxy and unsaturated polyester resins.
Finally, beams of each resin are actually cooled, and the residual stress and deformation in these beams is measured. The experimental results are compared with the theoretical results and the relations between the residual stress or deformation and thermoviscoelastic behavior are quantitatively explained.
