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The material point method (MPM) adopts the dual description of Lagrangian particles and Euler grids, so it can deal with large deformation and contact problems conveniently. The large deformation problem of thin shell structures was analyzed based on the framework of the convected particle domain interpolation material point method (CPDIMPM) . The quadrilateral mesh was used to discretize the shell structure. The basis function was calculated by the double mapping from the material point to the shell element node and then to the background grid node. The momentum equation was solved on the background grid, and the internal force of the material point was updated based on the Belytschko-Tsay (BT) shell element theory. In the numerical example, the comparison of large deformations of the shell structure with reference solutions verifies the accuracy of the proposed method. [ABSTRACT FROM AUTHOR]

Rubber material is widely used in practical engineering due to its good seismic and energy absorption effect. However, the collision of hyperelastic materials is a strong nonlinear problem. It is of great significance to analyze the contact collision and large deformation of hyperelastic materials to improve the buffering performance of the device. The smoothed finite element method (S-FEM) is a weak form of numerical calculation method. Compared with the traditional finite element method, the smoothed finite element method has low requirements on the mesh quality, allows the element to undergo large deformation during the calculation process, where the construction of the smooth domain is more flexible. The S-FEM has high accuracy without additional degrees of freedom. Based on the S-FEM, the double potential method was applied to contact calculation, with both advantages of the S-FEM in calculating large deformation problems and advantages of the double potential method in solving contact force fully used. In comparison with the numerical results of finite element software MSC. Marc, the results of the proposed algorithm were verified with high accuracy and good energy conservation, and the effects of the friction coefficient on the collision body were analyzed. [ABSTRACT FROM AUTHOR]

Red blood cell (RBC), undertaking the significant work of oxygen transport to maintain human life, could shuttle spindly capillaries by their own stretching and contractile properties due to their biconcave discoid shape and hyperelastic responses. In this paper, the coupled fluid-solid module in finite element software COMSOL was used to study the dynamic simulation of RBC when the three factors, including capillary width, plasma viscosity, and blood flow rate were considered. The results implied that the RBC could easily pass through capillary with hole size of 3 μm, and the aqueous shear stress was 4.5 times greater than that in the capillary with 6 μm hole size. Meanwhile, the plasma viscosity of 5.5 mPa·s induced parachute-like formation of RBC. Furthermore, biconcave structure in the center gradually disappeared and turned into bulge along the flow direction. With regard to the study on fluidic velocities in T-shaped and Y-shaped micro-channel, both results indicated that the asymmetric structure caused the falcate shape of RBC. In addition, the higher fluidic velocity in the other branch channel, the easier the convergence leaded to the disappearance of falcate shape and the rod posture lying flat flowing in the solution. [ABSTRACT FROM AUTHOR]