In the study of plastic constitutive relations, due to the 'single curve' hypothesis andthe yield conditions of the phenomenological theory, some theoretic problems about the proc-ess of plastic deformation ha...In the study of plastic constitutive relations, due to the 'single curve' hypothesis andthe yield conditions of the phenomenological theory, some theoretic problems about the proc-ess of plastic deformation have not yet been solved, and moreover, the constitutive relationsobtained with this method can only be approximately applied to some materials of excellentplastic performances. Plastic deformation in σ_m, τ_p, S_2 spaces has been analyzed according tothe 'similar curve' hypothesis and the rational yield condition obtained in σ_m, τ_p, S_2 spaces,a constitutive relationship of deformation theory of plasticity has been set up, which des-cribes better the laws of plastic deformation and voluminal deformation of all engineeringmaterials subjected to various stresses. By the characteristics of σ_m, τ_p, and S_2 and the inde-pendent deformations caused by them respectively, the problem about deviation from simpleloading has been solved, the cause of the loss of stability of materials under tension hasbeen theoretically given, some difficuties in the basic theory of plasticity have been over-come, and thus the basis has been laid down for a new theory system of plasticity.展开更多
文摘In the study of plastic constitutive relations, due to the 'single curve' hypothesis andthe yield conditions of the phenomenological theory, some theoretic problems about the proc-ess of plastic deformation have not yet been solved, and moreover, the constitutive relationsobtained with this method can only be approximately applied to some materials of excellentplastic performances. Plastic deformation in σ_m, τ_p, S_2 spaces has been analyzed according tothe 'similar curve' hypothesis and the rational yield condition obtained in σ_m, τ_p, S_2 spaces,a constitutive relationship of deformation theory of plasticity has been set up, which des-cribes better the laws of plastic deformation and voluminal deformation of all engineeringmaterials subjected to various stresses. By the characteristics of σ_m, τ_p, and S_2 and the inde-pendent deformations caused by them respectively, the problem about deviation from simpleloading has been solved, the cause of the loss of stability of materials under tension hasbeen theoretically given, some difficuties in the basic theory of plasticity have been over-come, and thus the basis has been laid down for a new theory system of plasticity.
