The mechanical properties of copper nanocubes by molecular dynamics are investigated in this paper. The [100], [110], [111] nanocubes are created, and their energies, yield stresses, hydrostatic stresses, Mises stress...The mechanical properties of copper nanocubes by molecular dynamics are investigated in this paper. The [100], [110], [111] nanocubes are created, and their energies, yield stresses, hydrostatic stresses, Mises stresses, and the relation- ships between them and strain are analyzed. Some concepts of the microscopic damage mechanics are introduced, which are the basis of studying the damage mechanical properties by molecular dynamics. The [100] nanocube exhibits homo- geneity and isotropy and achieves a balance easily. The [110] nanocube presents transverse isotropy. The [111] nanocube shows the complexity and anisotropy because the orientation sizes in three directions are different. The broken point occurs on a surface, but the other two do not. The [100] orientation model will be an ideal model for studying the microscopic damage theory.展开更多
A finite deformation problem is examined for a cylinder composed of a class of incompressible thermo-hyperelastic Mooney-Rivlin materials under an equal axial load at its two fixed ends and a temperature field at its ...A finite deformation problem is examined for a cylinder composed of a class of incompressible thermo-hyperelastic Mooney-Rivlin materials under an equal axial load at its two fixed ends and a temperature field at its lateral boundary. Firstly, a thermomechanical coupling term is taken into account in the strain energy density function, and a governing equation of the problem is obtained. Secondly, an implicit analytical solution is derived by using the incompressibility and the boundary conditions. Significantly, numerical examples show that the middle portion of the cylinder undergoes almost a uniform radial deformation. However, the deformation near the two ends varies remarkably along the axial direction for relatively large axial loads. In addition, the rising temperature can increase the deformation of structures, and its influence is linear approximately. Specially,in the case of tensile load, the jump increase of the axial deformation may occur.展开更多
The transverse stiffness and vibration characteristics of discontinuous beams can significantly differ from those of continuous beams given that an abrupt change in stiffness may occur at the interface of the former.I...The transverse stiffness and vibration characteristics of discontinuous beams can significantly differ from those of continuous beams given that an abrupt change in stiffness may occur at the interface of the former.In this study,the equations for the deflection curve and vibration frequencies of a simply supported discontinuous beam under axial loads are derived analytically on the basis of boundary,continuity,and deformation compatibility conditions by using equivalent spring models.The equation for the deflection curve is solved using undetermined coefficient methods.The normal function of the transverse vibration equation is obtained by separating variables.The differential equations for the beam that consider moments of inertia,shearing effects,and gyroscopic moments are investigated using the transfer matrix method.The deflection and vibration frequencies of the discontinuous beam are studied under different axial loads and connection spring stiffness.Results show that deflection decreases and vibration frequencies increase exponentially with increasing connection spring stiffness.Moreover,both variables remain steady when connection spring stiffness reaches a considerable value.Lastly,an experimental study is conducted to investigate the vibration characteristics of a discontinuous beam with a curvic coupling,and the results exhibit a good match with the proposed model.展开更多
The aim of this research is to assess the seismic performance of reinforced concrete columns under different axial load and transverse reinforcement ratios. These two parameters are very important as for the ductility...The aim of this research is to assess the seismic performance of reinforced concrete columns under different axial load and transverse reinforcement ratios. These two parameters are very important as for the ductility, strength, stiffness, and energy dissipation capacity for a given reinforced concrete column. Effects of variable axial load ratio and transverse reinforcement ratio on the seismic performance of reinforced concrete columns are thoroughly analyzed. The finite element computer program Seismo-Structure was used to perform the analysis of series of reinforced concrete columns tested by the second author and other researchers. In order to reflect the reality and grasp the actual behavior of the specimens, special attention was paid to select the models for concrete, confined concrete, and steel components. Good agreements were obtained between the experimental and the analytical results either for the lateral force-drift relationships or for the damage progress prediction at different stages of the loading.展开更多
文摘The mechanical properties of copper nanocubes by molecular dynamics are investigated in this paper. The [100], [110], [111] nanocubes are created, and their energies, yield stresses, hydrostatic stresses, Mises stresses, and the relation- ships between them and strain are analyzed. Some concepts of the microscopic damage mechanics are introduced, which are the basis of studying the damage mechanical properties by molecular dynamics. The [100] nanocube exhibits homo- geneity and isotropy and achieves a balance easily. The [110] nanocube presents transverse isotropy. The [111] nanocube shows the complexity and anisotropy because the orientation sizes in three directions are different. The broken point occurs on a surface, but the other two do not. The [100] orientation model will be an ideal model for studying the microscopic damage theory.
基金supported by the National Natural Science Foundation of China(Nos.11672069,11702059,11232003,and 11672062)the Ph.D Programs Foundation of Ministry of Education of China(No.20130041110050)+1 种基金the Natural Science Foundation of Liaoning Province of China(Nos.20170540199and 2014020137)the Programme of Introducing Talents of Discipline to Universities(No.B08014)
文摘A finite deformation problem is examined for a cylinder composed of a class of incompressible thermo-hyperelastic Mooney-Rivlin materials under an equal axial load at its two fixed ends and a temperature field at its lateral boundary. Firstly, a thermomechanical coupling term is taken into account in the strain energy density function, and a governing equation of the problem is obtained. Secondly, an implicit analytical solution is derived by using the incompressibility and the boundary conditions. Significantly, numerical examples show that the middle portion of the cylinder undergoes almost a uniform radial deformation. However, the deformation near the two ends varies remarkably along the axial direction for relatively large axial loads. In addition, the rising temperature can increase the deformation of structures, and its influence is linear approximately. Specially,in the case of tensile load, the jump increase of the axial deformation may occur.
基金Support provided by the Ministry of Industry and Information Technology of China(Grant No.JSZL2016204B102)the National Natural Science Foundation of China(Grant Nos.51575022 and 11772022).
文摘The transverse stiffness and vibration characteristics of discontinuous beams can significantly differ from those of continuous beams given that an abrupt change in stiffness may occur at the interface of the former.In this study,the equations for the deflection curve and vibration frequencies of a simply supported discontinuous beam under axial loads are derived analytically on the basis of boundary,continuity,and deformation compatibility conditions by using equivalent spring models.The equation for the deflection curve is solved using undetermined coefficient methods.The normal function of the transverse vibration equation is obtained by separating variables.The differential equations for the beam that consider moments of inertia,shearing effects,and gyroscopic moments are investigated using the transfer matrix method.The deflection and vibration frequencies of the discontinuous beam are studied under different axial loads and connection spring stiffness.Results show that deflection decreases and vibration frequencies increase exponentially with increasing connection spring stiffness.Moreover,both variables remain steady when connection spring stiffness reaches a considerable value.Lastly,an experimental study is conducted to investigate the vibration characteristics of a discontinuous beam with a curvic coupling,and the results exhibit a good match with the proposed model.
文摘The aim of this research is to assess the seismic performance of reinforced concrete columns under different axial load and transverse reinforcement ratios. These two parameters are very important as for the ductility, strength, stiffness, and energy dissipation capacity for a given reinforced concrete column. Effects of variable axial load ratio and transverse reinforcement ratio on the seismic performance of reinforced concrete columns are thoroughly analyzed. The finite element computer program Seismo-Structure was used to perform the analysis of series of reinforced concrete columns tested by the second author and other researchers. In order to reflect the reality and grasp the actual behavior of the specimens, special attention was paid to select the models for concrete, confined concrete, and steel components. Good agreements were obtained between the experimental and the analytical results either for the lateral force-drift relationships or for the damage progress prediction at different stages of the loading.
