Papers by Keyword: Coupled

Abstract: To quickly predict the performance of the seat in frontal crash during the initial stage of the seat development, in this paper a simplified coupled dynamic model of seat-passenger interaction is established according to the dynamics analysis method of Lagrange, and the fourth order Runge-Kutta method is used to resolve differential equation. Moreover, the simulation of Madymo testifies the simplified coupled dynamic model of seat-passenger interaction in frontal crash. Therefore, this model will be effective and feasible in predicting the performance of the seat in frontal crash during the initial stage of the seat development, for example, the performance of anti-submarining protection.

Abstract: For the sake of reflecting the concentrated heat flux distribution boundary condition as genuine as possible during simulation, the sequential coupled optical-thermal heat transfer analysis is introduced for porous media receiver. During the sequential coupled numerical analysis, the non-uniform heat flux distribution on the fluid entrance surface of porous media receiver is obtained by Monte-Carlo ray tracing method. Finite element method (FEM) is adopted to solve energy equation using the calculated heat flux distribution as the third boundary condition. The dimensionless temperature distribution comparisons between uniform and non-uniform heat flux distribution boundary conditions, various porosities, and different solar dish concentrator tracking errors are investigated in this research.

Abstract: This paper deals with the possibilities of using coupled timber-concrete structures by means a glued coupling bar. The described process of static reinforcement is particularly suitable for reconstruction of historic timber ceilings and places where it is necessary to prevent damage to non-supporting structures (e.g. ceiling, plaster, stucco decorations, etc.). The method is also employed in those cases where it is necessary to allow traffic-flow in the rooms below the reconstructed ceiling. The article describes the specific technological process that has been examined in the reconstruction of the ceiling structure of a house on Sokolska Street in Ostrava. Following experimental testing in laboratories at the Faculty of Civil Engineering VSB - TU Ostrava the technology of bonded shear bars under static reinforcement of timber ceilings was first applied and successfully tested in construction practice.

Abstract: Based on FLAC^2d with its built-in fish language, the coupled procedure of the overland runoff and the unsaturated water-gas two phases seepage model has been compiled. On the assumption that the slope surface is impervious, with the analytic solution of the overland runoff, the numerical solution has been investigated and with the example analysis, it is shown that in order to accurately assess the rainfall influence on the slope stability, the coupled boundary and the water-gas two phases flow should be taken into consideration in numerical simulation

Abstract: A coupled elastoplastic damage model is proposed for the description of anisotropic concrete under compression-dominated stresses. The model is applied to typical concrete in various loading conditions. Damage evolution law and plastic damage coupling are described by using the framework of irreversible thermodynamics.

Abstract: In this study, the latest version of river boundary modular in MODFLOW, was employed in this watershed for the case study of coupled calculation between river and aquifer. Because of the complex interaction of groundwater and surface water in this area, the coupling model of SFR modular for river diffusive wave model and isochronal cell method for overland flow confluence model and numerical calculation of groundwater is coupled to simulate the runoff process of Weihe river. The model validation was aiming at river flow rate and groundwater field. The results show that 65% of the abstracted shallow groundwater comes from the river water and the reduced amount of river baseflow by the groundwater abstraction is 122 million m3 per year, which is also validated by a water balance analysis of river links. The 50% reduction of shallow groundwater abstraction may lead to a recover of 3 m of the lowest groundwater level. The study provides a sound analysis tool to the integrated water resources and ecology management in the region.

Abstract: Ring rolling process, especially hot rolling is characterized by 3D deformation, continuous change of thickness and height, high nonlinearity, non-steady flow and asymmetry. It involves both mechanical and thermal behaviors. Most mechanical and physical properties and boundary conditions are temperature related. The heat flow and stress analysis cannot be analyzed separately. In this study, both isothermal and coupled thermo-mechanical (CTM) 3D rigid-plastic finite element (FE) models of the hot ring rolling (HRR) process are developed to investigate their differences in accurately and quickly predicting the process. The results show that the latter should be more advantageous to the more accurate prediction and control of microstructure and properties of the ring.

Abstract: Based on extended finite element coupled with field variable method, fatigue damage numerical test of three point-bending beam with initial notch has been made to predict crack propagation path, numerical results showed : under the fatigue loading with 200Hz, and amplitude is 20KN, length of crack expanding was the biggest and crack grew as some angles with the initial crack during the first loading, crack propagated parallel to the initial angle during the other loading cycle. These results can fit the experiment very well. Using Fortran, A new user subroutine named USDFILD (User subroutine to redefine field variables at a material point) was also provided on the platform of ABAQUS, which can modal the change of physic material with time. This user subroutine can also import fatigue characterize of material into the model.

Abstract: This paper proposed an improved thermal-electric-displacement FEM model for spark plasma sintering (SPS), which fully considered the variations of therma-electrical material parameters, contact resistances and contact boundaries due to the densification process. The simulation shows that such an alterable boundary condition builds a remarkable temperature gradient in the axial direction along the inner wall of the die, and the local change of the temperature at the contact interfaces can be described more exactly. The experiment and the simulation are in a great agreement. The developed SPS model can be used as an aiding tool to optimize the SPS process parameters of metal powders.

Abstract: The diffusion performance of chloride ion in concrete under the coupling action of dynamic load and environment was researched by a new set of experimental system. The experiment are composed of study of saturated performance of concrete, diffusion performance of chloride ion with different water binder ratio and under coupling action of dynamic load and temperature. The results show that the transport mechanism of chloride ion in concrete accounted with diffusion theory due to the 99% of saturation degree of concrete; the diffusion coefficient of chloride ion is decreased with the increasing water binder ratio, but is increased with temperature increase; and the diffusion coefficient of chloride ion is changed with cycle number.