Applied Mechanics and Materials Vols. 353-356

Abstract: Based on the dynamic viscous-spring artificial boundary and explicit finite element code, a numerical simulation of explosion process with concentrated charge in a mass of soil was carried out by using viscous-spring artificial boundary element. The results were compared with viscous boundary and far-field boundary based on dynamic response of soil medium and the explosion wave propagation law in soil. The results show that equivalent viscous-spring boundary element effectively reduce the boundary effect and has high solution precision and efficiency for simulation of blasting in soil.

Abstract: Based on relationship between elastic and plastic strain, a new basic equation system of plasticity mechanics was established. In this paper, modification is made to the new basic equation system, and another form of basic equation system is presented based on stress strain constitutive relation, which also makes it possible to apply the results from elasticity mechanics directly to plasticity mechanics and decreases the solving difficulty of plastic problem. Finally, a simple application example is given, which shows that the new form of basic equation system is correct and practicable.

Abstract: In this paper, a partially linear model under longitudinal data is considered. In order to take into consideration the within-subject correlation structure of the repeated measurements, an empirical likelihood incorporating the correlation structure is developed. The asymptotic normality of the maximum empirical likelihood estimates of the regression coefficients is obtained. It also can be shown that the proposed empirical likelihood ratio is asymptotically standard chi-square. The results can be used directly to construct the asymptotic confidence regions of the regression coefficients. The convergence rate of the baseline function is derived.

Abstract: This paper, which based on the conventional dynamic programming solution , using the method that the decision variables of various stages are fully discrete in their feasible region to solve the optimal target function value under the various state variables. The method can be generic in solving the maximum and minimum objective function value, while avoiding the problem of the different discrete step lengths of the state variables lead to lower the precision of the target value. So, the method will make the solution process of the various stages more specific image, contributing to combining with the practical problems and understanding the connotation of the practical problems (e.g. water resource optimization allocation ).

Abstract: Bending, longitudinal and shear waves being taken into account, the transmission and reflection coefficients at the junction of the L-shaped plates are investigated. Based on a special procedure to deal with the global matrix assembly, the wave energy governing equations are proposed to calculate the energy density and intensity of the coupled plates to investigate the transmission properties. Some conclusions are obtained by the numerical examples.

Abstract: A coupled method between the Scaled Boundary Finite Element Method (SBFEM) and Finite Element Method (FEM) for evaluating the Stress Intensity Factors (SIFs) is presented and achieved on the platform of the commercial finite element software ABAQUS by using Python as the programming language. Automatic transformation of the finite elements around a singular point to a scaled boundary finite element subdomain is realized. This method combines the high accuracy of the SBFEM in computing the SIFs with the ability to handle material nonlinearity as well as powerful mesh generation and post processing ability of commercial FEM software. The validity and accuracy of the method is verified by analysis of several benchmark problems. The coupled algorithm shows a good converging performance, and with minimum additional treatment can be able to handle more problems that cannot be solved by either SBFEM or FEM itself. For fracture problems, it proposes an efficient way to represent stress singularity for problems with complex geometry, loading condition or certain nonlinearity.

Abstract: Elastic modulus is an important parameter in structural analysis. This paper identifys the structural elastic modulus with measured displacements, which is an inverse problem. The improved genetic algorithm combined with multi-cases measurement is applied in the solution. Numerical examples have proved that the method is available.

Abstract: Considering high compressive strength of high-strength concrete, it is assumed that concrete compressive stress of the cross-section compression zone is linear distribution when the cross-section of high-strength concrete shear wall reaches yield situation. Based on the plane section assumption, the yield curvature formula of shear wall section is obtained by using moment - curvature analysis method. The parameters effecting yield curvature of high-strength concrete shear wall are studied by using the yield curvature formula. The results show that longitudinal reinforced yield strain is the most influencing factor of the yield curvature in addition to axial load ratio. This paper presents yield curvature formula considering the impact of axial load ratio and boundary reinforcement yield stress through the regression analysis of calculation results. On this basis, the vertex yield displacement formula of high-strength concrete shear wall is proposed, and the calculation results of formula correspond to the vertex yield displacement experimental values of the 12 high-strength concrete cantilever wall well.

Abstract: Large deflection of a cantilever nanobeam subjected to a tip-concentrated load whose verticality to the deformed axis of the beam is assumed as constant. Governing equation is analyzed by using the shearing force formulation instead of the bending moment formulation because in the case of large deflection member, the shearing force formulation possesses some computational advantages over the bending moment formulation. The condition of boundary is discussed by several ways. The different sizes of loads and time scales are used to analyze the deformation and the different by molecular dynamics.

Abstract: Based on mechanical characteristics of the single layer latticed shell member, two buckling types of structural compression members are summarized. The pre-buckling and post-buckling mechanical behaviors of the member are simulated by different calculating model, and the member calculating model are founded by which the likely buckle-straighten processes of the member and the form-disappear processes of the plastic hinge can be simulated. Numerical computing results indicate that based on the member calculating model presented in this paper, the changes of member mechanical behaviors and the consequent complex changes of structural bearing capacity in the seismic dynamic responses process of single layer latticed shell can be calculate accurately, and the refined simulation of the full-range dynamic response process for single layer latticed shell subject to dynamic excitation are realized.