The stress distribution of notched specimen of brittle material under a plane pressure was studied using a photoelastic meth- od,When elastic deformation appeared inside the specimen,the force transferred by dowel par...The stress distribution of notched specimen of brittle material under a plane pressure was studied using a photoelastic meth- od,When elastic deformation appeared inside the specimen,the force transferred by dowel part was triangular transverse force and frictional force on the upper surface of the sample.The quantity of the frictional force was about 31 percent of transverse force.The stress inside the sample was linear along the central cross section of the sample and there was maximum tensile stress σ_y at the tip of the notch.Basing on shearing stress deviation method,the tensile stress σ_y,σ_x and shearing stress τ_(xy) at the cen- tral sections and four adjacent cross sections were calculated.The result pointed out that σ_x and τ_(xy) were smaller than σ_y.There- fore,σ_y was the main factor for crack formation and propagation.展开更多
In order to predict the life of engineering structures, it is necessary to investigate the strain distribution in notched members. In gineral, the Uauschinger Effect of materials under cyclic loading is not negligible...In order to predict the life of engineering structures, it is necessary to investigate the strain distribution in notched members. In gineral, the Uauschinger Effect of materials under cyclic loading is not negligible, and so the anisolropic hardening model has been suggested. From the comparison between the calculated and experimental results in this paper, we can see that even the linear kinematic hardening model is quite suitable for strain analysis under cyclic loading.展开更多
In this paper, the boundary element method is applied to investigate the internal state of stress of autofretted tube with notch and the calculated results are important in the practical design.
Experimental investigation and numerical modeling on elasto-plastic notch-root stress/strain distributions under monotonic loadings of both the Ni-based directionally solidified(DS)superalloy and Titanium alloy were c...Experimental investigation and numerical modeling on elasto-plastic notch-root stress/strain distributions under monotonic loadings of both the Ni-based directionally solidified(DS)superalloy and Titanium alloy were carried out simultaneously.For measuring inhomogeneous deformation fields at notch roots,an optical-numerical full-field surface deformation measurement system was developed based on the digital image correlation(DIC)method.The obtained strain distributions were then verified with reasonable accuracy by finite element simulation,where an anisotropic elastic-viscoplastic constitutive model was developed for DS superalloy and a simple isotropic stress-strain relationship was adopted for Titanium alloy.Meanwhile,factors affecting elasto-plastic notch-root stress/strain distributions were systematically investigated numerically,where the emphasis was placed on temperature,loading stress rate,sample shape,anisotropy and notch features.The results show that stress/strain behavior at notch root is significantly affected by the mentioned factors,which are concretely embodied in the distribution of tensile stress/strain,equivalent stress and accumulative equivalent plastic strain.展开更多
文摘The stress distribution of notched specimen of brittle material under a plane pressure was studied using a photoelastic meth- od,When elastic deformation appeared inside the specimen,the force transferred by dowel part was triangular transverse force and frictional force on the upper surface of the sample.The quantity of the frictional force was about 31 percent of transverse force.The stress inside the sample was linear along the central cross section of the sample and there was maximum tensile stress σ_y at the tip of the notch.Basing on shearing stress deviation method,the tensile stress σ_y,σ_x and shearing stress τ_(xy) at the cen- tral sections and four adjacent cross sections were calculated.The result pointed out that σ_x and τ_(xy) were smaller than σ_y.There- fore,σ_y was the main factor for crack formation and propagation.
文摘In order to predict the life of engineering structures, it is necessary to investigate the strain distribution in notched members. In gineral, the Uauschinger Effect of materials under cyclic loading is not negligible, and so the anisolropic hardening model has been suggested. From the comparison between the calculated and experimental results in this paper, we can see that even the linear kinematic hardening model is quite suitable for strain analysis under cyclic loading.
文摘In this paper, the boundary element method is applied to investigate the internal state of stress of autofretted tube with notch and the calculated results are important in the practical design.
基金supported by the National Natural Science Foundation of China(Grant No.51275023)the Innovation Foundation of BUAA for PhD Graduates(Grant No.YWF-14-YJSY-49)
文摘Experimental investigation and numerical modeling on elasto-plastic notch-root stress/strain distributions under monotonic loadings of both the Ni-based directionally solidified(DS)superalloy and Titanium alloy were carried out simultaneously.For measuring inhomogeneous deformation fields at notch roots,an optical-numerical full-field surface deformation measurement system was developed based on the digital image correlation(DIC)method.The obtained strain distributions were then verified with reasonable accuracy by finite element simulation,where an anisotropic elastic-viscoplastic constitutive model was developed for DS superalloy and a simple isotropic stress-strain relationship was adopted for Titanium alloy.Meanwhile,factors affecting elasto-plastic notch-root stress/strain distributions were systematically investigated numerically,where the emphasis was placed on temperature,loading stress rate,sample shape,anisotropy and notch features.The results show that stress/strain behavior at notch root is significantly affected by the mentioned factors,which are concretely embodied in the distribution of tensile stress/strain,equivalent stress and accumulative equivalent plastic strain.
