We investigated the combined influence of joint inclination angle and joint continuity factor on deforma- tion behavior of jointed rock mass for gypsum specimens with a set of non-persistent open flaws in uni- axial c...We investigated the combined influence of joint inclination angle and joint continuity factor on deforma- tion behavior of jointed rock mass for gypsum specimens with a set of non-persistent open flaws in uni- axial compression. Complete axial stress-strain curves were classified into four types, i.e., single peak, softening after multi-peak yield platform, hardening after multi-peak yield platform and multi-peak dur- ing softening. Observation of crack evolution on the specimen surface reveals that the deformation behavior is correlated to the closure of pre-existing joint, development of fractures in rock matrix and teeth shearing of the shear plane. To investigate the brittleness of the specimens, the ratio of the residual strength to the maximum peak strength as well as the first and last peak strains were studied. At the same joint inclination angle, the ratios between residual strength and the maximum peak strength and the last peak strains increased while the first peak strain decreased with the increase of joint continuity factor. At the same joint continuity factor, the curves of the three brittleness parameters vs. joint inclina- tion angle can either be concave or convex single-oeak or wave-shaoed.展开更多
The Ce/Cr coating was homogenously deposited onto the reticulated open-cell Ni?Cr?Fe alloy foam by the pack cementation process.The mechanical properties of the Ce/Cr coated alloy foams were investigated by the quasi-...The Ce/Cr coating was homogenously deposited onto the reticulated open-cell Ni?Cr?Fe alloy foam by the pack cementation process.The mechanical properties of the Ce/Cr coated alloy foams were investigated by the quasi-static compression test.Simultaneously,the deformation and failure mechanisms of Ce/Cr coated alloy foams were discussed.The results show that the adding amount of CeO2powders influences the mechanical properties of the Ce/Cr coated alloy foams.Despite an increase in density as compared to the uncoated foams,the Ce/Cr coated foams exhibit improvement in both yield strength and energy-absorption performance.Especially,the energy-absorption performance of2%Ce/Cr(mass fraction)coated alloy foam is averagely1.9times as high as that of the bare Ni?Cr?Fe alloy foam.In addition,the mechanical properties of the Ce/Cr coated alloy foams increase with the increase of strain rate.The distortion and cracking are mainly the deformation behavior of the Ce/Cr coated alloy foam,confirmed by SEM images.展开更多
基金supported by the National Natural Science Foundation of China (No. 11102224)the Fundamental Research Funds for the Central Universities of China(No. 2009QL05)
文摘We investigated the combined influence of joint inclination angle and joint continuity factor on deforma- tion behavior of jointed rock mass for gypsum specimens with a set of non-persistent open flaws in uni- axial compression. Complete axial stress-strain curves were classified into four types, i.e., single peak, softening after multi-peak yield platform, hardening after multi-peak yield platform and multi-peak dur- ing softening. Observation of crack evolution on the specimen surface reveals that the deformation behavior is correlated to the closure of pre-existing joint, development of fractures in rock matrix and teeth shearing of the shear plane. To investigate the brittleness of the specimens, the ratio of the residual strength to the maximum peak strength as well as the first and last peak strains were studied. At the same joint inclination angle, the ratios between residual strength and the maximum peak strength and the last peak strains increased while the first peak strain decreased with the increase of joint continuity factor. At the same joint continuity factor, the curves of the three brittleness parameters vs. joint inclina- tion angle can either be concave or convex single-oeak or wave-shaoed.
基金Project(51501133)supported by the National Natural Science Foundation of ChinaProject(T201629)supported by the Universities of Hubei Province Outstanding Young Scientific and Technological Innovation Team Plans,ChinaProject(AWJ-M16-11)supported by the State Key Laboratory of Advanced Welding and Joining,Harbin Institute of Technology,China
文摘The Ce/Cr coating was homogenously deposited onto the reticulated open-cell Ni?Cr?Fe alloy foam by the pack cementation process.The mechanical properties of the Ce/Cr coated alloy foams were investigated by the quasi-static compression test.Simultaneously,the deformation and failure mechanisms of Ce/Cr coated alloy foams were discussed.The results show that the adding amount of CeO2powders influences the mechanical properties of the Ce/Cr coated alloy foams.Despite an increase in density as compared to the uncoated foams,the Ce/Cr coated foams exhibit improvement in both yield strength and energy-absorption performance.Especially,the energy-absorption performance of2%Ce/Cr(mass fraction)coated alloy foam is averagely1.9times as high as that of the bare Ni?Cr?Fe alloy foam.In addition,the mechanical properties of the Ce/Cr coated alloy foams increase with the increase of strain rate.The distortion and cracking are mainly the deformation behavior of the Ce/Cr coated alloy foam,confirmed by SEM images.
