Applied Mechanics and Materials Vols. 275-277

Abstract: This paper discusses the laminated structure and sandwich structure by finite element modeling, the process of finite element modeling of composite panel with top-hat stiffeners and finite element analysis of the whole hull. The result shows that the method and steps of modeling FRP yacht based on FEM to directly calculate the hull structural strength are instructive.

Abstract: Experimental and Finite Element analysis was used for the investigation of the effect of cell size and thickness on the compressive properties of Aluminium honeycomb core. Honeycomb cores were compressed experimentally in in-plane and out of plane directions. The effect of sample size, cell size and thickness on the elastic modulus, yield strength and plateau stress was investigated through FEA. It was found that the mechanical response was independent upon the sample size in in-plane direction. The smallest cell size honeycomb core was deformed at higher yield stress. Similarly, with increase in cell wall thickness, the modulus of the core increased.

Abstract: The objective of this study was to investigate the relationship between fabric property and Clothing Pressure of knitted underwear, using objective pressure evaluates method. Eight kinds of fabric for knitted underwear were tested on the stretching property and elasticity property, and then eight same style of underwear which were made by Eight kinds of fabric were tried on by pressure dummy. Clothing pressure of seven different points was measured and recorded. The linear relationship between fabric property and Clothing Pressure of knitted underwear was obtained. Results showed that Clothing Pressure of knitted underwear was negative correlation with elastic recovery rate of knitted fabric, and was positive correlation with tensile stretch rate.

Abstract: The oblique shock wave theory is used to describe the process of detonation wave shocking on the metal surface. And after the transmission wave in metal transmitted to the free surface of metal, the velocity multiplication law of free surface is used to simplify the shock wave theory to estimate the velocity of particles in metal. Then the projection angle is obtained from the velocity direction to the normal of initial metal surface. In addition, the explosion experiments of a D shape configuration have been done to validate this method. And the results show that this method is in better agreement with experimental projection angles than traditional Taylor equation.

Abstract: It is very important to draw internal forces diagram(shear diagram, bending moment diagram)of beam quickly and accurately for students. Only hold its regular and can use proficiently, we can laid a solid foundation for the study of specialized course .This article mainly based on the characteristics of the beam, analyzed shape and laws of the internal forces diagram and summary of the methods ----"pithy formula law"

Abstract: The bending behavior of single- and polycrystalline thin films is modeled by two-dimensional discrete dislocation dynamics (DDD) to study the cyclic bending response. In the polycrystalline films, grain boundaries (GBs) are simulated with a penetrable dislocation-GB interaction model. Our results reveal that the single- and polycrystalline thin films under pure bending exhibit strong Bauschinger effect but no cyclic hardening or softening. Furthermore, the uploading response of each cycle can be divided into three stages, which are associated with the glide, annihilation and nucleation of dislocations, respectively.

Abstract: An unstructured moving grid scheme is applied to track the real-time motion state of the material interface with large-scale deformation induced by shock in the compressible multi-material flow. The material interface is denoted as a special internal boundary which is made up of unstructured grid edges, and on both sides of that there exist grids used for the two different materials. Riemann problem is solved in order to track the motion of the grid points on the material interface, and the local re-meshing technique is also applied to cope with the large-scale deformation of the moving grids near the interface, especially for the case of strong shocks existing in the multi-material flows. Simultaneously, the material interface is also defined as a kind of grid-deforming boundary in case grid volumes are negative. To obtain the resolution of the whole multi-material flow domain, the arbitrary Lagrangian-Eulerian (ALE) is discretized using Harten-Lax-van Leer-Contact (HLLC) scheme. Several numerical calculations from shock-interface examples demonstrate that this moving grid technique is feasible and effective in tracking the real-time motion state of the material interface.

Abstract: A thermal shock problem of a functionally graded material plane (FGMP) containing a crack is considered. All the material properties of the FGMP are assumed to be dependent on the coordinates.The transient temperature fields are solved by combining the finite difference method (FDM) and the finite element method (FEM). Then the transient thermal stress intensity factors (TSIFs) are obtained using the interaction energy integral method. The transient characteristics of the TSIFs are investigated.

Abstract: Real-time displacement in stable crack tearing was measured by digital image correlation technique. Quantitative analyses were provided on mixed-mode Ⅰ/Ⅱ fracture and critical CTOA for recycled thin sheet metals. It is shown that the fracture of recycled thin sheet metals is tough due to the large plastic deformation, and mixed-mode crack is easier to extend than mode Ⅰ crack. The critical CTOA at stable crack tearing is constant and can be used as a fracture criterion for the thin sheet metals.

Abstract: An interface crack problem in two nonhomogeneous plates under thermal loading is investigated. The interaction energy integral method (IEIM) is developed for obtaining the mixed-mode thermal stress intensity factors (TSIFs) of interface crack. The domain-independence of the present IEIM is verified. Numerical examples are presented and the results show good agreement with the analytic ones. Numerical results show that the method is very effective for the thermal interface crack of nonhomogeneous plate.