Applied Mechanics and Materials Vols. 166-169

Abstract: A prey-predator model was considered. Using the methods of the modern nonlinear dynamics and homotopy analysis method (HAM), its stability was discussed. Firstly, we found the system’s positive equilibrium point and shifted it to zero point through transformation. Secondly, we analyzed the stability of the system at the equilibrium point. Lastly, we analyzed the transformed system by HAM. We support our analytical findings with numerical simulation.

Abstract: Based on the analysis of the woven structure, the compressive fracture process and strength of a 2.5D-C/SiC ceramic matrix composite were investigated by the classical laminate theory. The porous composite was regarded as a spatial layered structure, and the two classes of the warps and wefts in the 2.5D-C/SiC composite were treated as the corresponding layers. The strengths of the C/SiC bundle and C/SiC lamina were determined, and the compression strength for the composite was calculated by progressive fracture method of the layers and elastic degradation. The failure mechanisms and the angles of the compressive fracture surfaces coincided with the experimental result well. It was demonstrated that the strength predictive method of the classical laminate theory can be applied to the analysis of 2.5D-C/SiC composite.

Abstract: This paper presents comparison of calculation methods on bi-directional shearing capacity of RC framed columns, mainly analyzing on the characteristics of the different method. It is demonstrated that the code method, the minimum volume of steel method,the simplified tri-linear analytical method are all derived from over-strength factor method.The difference among them is only different over-strength factor.Their three over-strength factors are to reduce all bearing capacity item,while the proposed method is only the parts of reduction to bearing capacity item. From the veiw of designing for security, all methods can meet the requirement of safety.

Abstract: The shape function of the meshless local radial point interpolation method is constructed by using the radial basis functions and possesses Kronecker delta function properties. Therefore, the essential boundary conditions can be easily imposed. Causation of shear locking occur in plate bending is analyzed. Bending problems for plate with two sides simply supported, the other two sides clamped boundary conditions, are analyzed by the meshless local radial point interpolation method. The shear locking is easier avoided in the meshless method than in the finite element method, and the measure of avoiding the shear locking are presented.

Abstract: To consider the deformation of thin rectangular plate under temperature. In this paper, the wavelet multi-scale method was used to solve the thin plate governing differential equations with four different initial or boundary conditions. An operational matrix of integration based on the wavelet was established and the procedure for applying the matrix to solve the differential equations was formulated, and got the deflection of thin rectangular plates under temperature. The result provides a theoretical reference for solving thin rectangular plate deflection in thermal environment using multi-scale approach.

Abstract: Study on dynamic stability of structure is a hot subject in the fields of engineering mechanics, but its basic theory and analytical method still need to be further improved. This paper improved the current method for dynamic stability analysis called “dynamic eigenvalue method”, and the method for nonlinear dynamic stability analysis based on ANSYS platform is proposed. A long column under harmonic loads is taken as the research objective, dynamic eigenvalues affected by the load frequency, load amplitude and damping ratio are studied. Results show that, the increasing of load frequency or dynamic load amplitude will lead to the increase of maximum dynamic eigenvalue and decrease of minimum dynamic eigenvalue, which is not beneficial to dynamic stability of structure. The increasing of damping ratio will lead to the decrease of maximum dynamic eigenvalue and increase of minimum dynamic eigenvalue, this make the dynamic eigenvalue more stable. Therefore, the high damping is beneficial to dynamic stability of structure.

Abstract: Based on the J-A₂ two-parameter elastic-plastic fracture theory and finite element numerical method, the elastic-plastic stress field ahead of the crack tip in a single edge cracked eccentric tensile specimen (the load-line is at a finite distance from the crack tip) was analyzed and compared with that of a center cracked large plate under biaxial loading. By using the Ritchie-Knott-Rice fracture criterion, a transformational relation between the two loading modes was obtained based on the J-A₂ equivalent principle. As a result, the fracture parameter determined from a single edge cracked eccentric tensile specimen can be applied to the fracture analysis of a center cracked plate under biaxial stress.

Abstract: The structural diaphragm effects have been investigated in the past decades with major attention on the properties of diaphragm panels. The research observations made by the oversea researchers cannot be directly utilized to the design construction of Chinese light gauge steel structures due to the different configuration of profiled steel sheets, fasteners, and purlins in China. In this regard, the shearing strength and stiffness of diaphragm steel sheets are investigated in this study through numerical study. The profiled steel sheet and fastener are simulated by the ortho-anisotropic flat plate and three one dimensional nonlinear spring, respectively. The analytical models are developed for examining the shearing strength and stiffness induced by diaphragm effects of a cladding system. The made observations indicate that the diaphragm effects of the steel sheet on the structure are obvious.

Abstract: As asphalt Pavement possesses the characteristics of comfort and ease to maintenance, it exerts usually in the road construction. Heavy axle load and high wheel pressure make the asphalt road prone to rutting damage. Based on the constitutive model of asphalt mixture, the paper analyzes mechanical properties of modulus, shear force and peak deflection value for different asphalt surface course after adding the rutting agent using the finite element method. Finally the paper acquires mechanism of variation in rutting, which provides an important theoretical basis for the final asphalt pavement structural design.

Abstract: The effect of the thermal shock temperature on the thermal stress distributed in the adhesively bonded steel single lap steel joint under a 10 s thermal shock was investigated using elasto-plastic finite element method (FEM). The results showed that both the highest temperature at the surface and the lowest one at the mid-bondline increases as the temperature of the thermal shock raised (80 C to 140 C) and all the peak values of the stresses at the mid-bondline and the zone of negative Sx in adherend increased as the temperature of the thermal shock elevated.