Papers by Keyword: Discrete Element

Abstract: Geothermal energy piles have emerged as a cost effective and efficient solution for heating and cooling buildings through renewable energy. Although significant research effort has been dedicated to investigating the performance of these systems, the effect of ground mineralogy has received little attention. This study examines the likely performance of energy piles in dense sand with varying mineralogy. A 3D thermal discrete element model is used to determine the dry thermal conductivity of quartz, feldspar and mica rich sand. This is then used in a 2D finite element analysis to estimate the dissipation/extraction capacity of the soil surrounding a typical energy pile. A 35% increase in quartz content is predicted to result in 51% improvement in the thermal performance of a pile.

Abstract: This paper describes the mechanism of a small dual-planetary ball mill which is used in the laboratory, and using the discrete element software PFC3D to establish corresponding model of the milling tank in dual-planetary ball mill and the ball medium in tank. The big wheel under different rotational speed affects the average contact stress and the different filling rate of 8 mm ball medium affects the average stress, which are applied to simulation research, and we draw the corresponding conclusion.

Abstract: After analyzing the propagation of stress wave at different angles of inclination, strength parameters and the group number of structural plane. The results of research are summarized as follows: Due to the change of propagation direction in structural planes with different angles of inclination, the original propagation rule of stress wave changes too, the peak velocity of the monitory point gets relatively flat as the strength parameters of structural plane turn greater. Stress wave repeatedly refracts and reflects in many groups of structural plane, then the appropriate dynamic characteristics of the wave no longer maintains as the number of group increases or decreases. By analyzing and verifying the slope instance, the test result provides a reference for studying dynamic response rules.

Abstract: During the rice mill structural design process, static analysis is an extremely important field, not only decide to what the structure size is, but also for the subsequent fatigue analysis, providing the basis for the overall stability analysis. In this paper, vertical screw conveyor vertical rice mill, rice discrete element analysis simulation under different speed, the internal movement of materials to simulate the process for improving the productivity of the vertical screw conveyor has a certain significance. Providing an important basis for further design optimization of the rice mill structure.

Abstract: A Finite Elements formulation previously developed for Cosserat elastic plates, has been extended herein to the elastoplastic framework. Material non-linearities are taken into account through the implementation of a backward-Euler closest-point-projection algorithm, for which the definition of non-smooth yield loci and non-associated plastic potentials and evolution laws is made possible. An existing homogenized elastic constitutive model and a set of yield criteria for the out-of-plane behaviour of block-masonry are implemented in the code and their validity is discussed based on the comparison with Discrete Elements simulations. The comparison is carried out in both the static and the dynamic regime.

Abstract: Discrete element software is used to simulate the excavation of a rock slope in Puli-Xuanwei Expressway in Yunnan Province. Through monitoring displacement development characteristics in different positions of slope, the result shows that the minimum horizontal displacement under excavation exists in the top of the slope, meanwhile the maximum horizontal displacement occurs in the foot and waist of the slope, and the maximum vertical displacement occurs in the top of the slope. Comparing rock slope in such conditions as different stratum angles, directions, rock characteristics and thickness, it concludes possible failure modes of slope and the variation law of safety coefficient under different conditions. This paper is instructive and offers reference for the practical engineering.

Abstract: This paper is based on the kinetic theory of ore and steel balls in the SAG Mill and theoretical research of power consumption. Orthogonal method is taken to design experimental plan while effective power of the SAG Mill, collision times between steel balls and the SAG Mill and collision times between steel balls and ore are designed as optimal objectives. Model with 9 experimental points is simulated by EDEM and experimental data are disposed Range Method in order to get the optimal combination of operating parameters of the SAG Mill.

Abstract: The mechanics mechanism of bolt reinforcement of joint fissure test pieces were discussed with the method of variable angle plate indoor model experiment and the deformation of bolt control of jointed slope were analyzed by numerical simulation. The results show that: the bolt reinforcement can improve not only the integrity of joint fissure rock mass, but also be a very good control of deformation of jointed slope. It establishes the foundation on the quantitative for evaluation of joint fissure rock mass deformation and stability.

Abstract: According to the actual working condition of the full face hard rock tunnel boring machine (TBM), a 2-D discrete element model for breaking marble by two TBM disc cutters is established, it simulates the whole progress of cracks production and propagation under different confining stress and penetration; based on CSM prediction model, forces of two cutters and specific energy consumptions are calculated to determine the best penetration. The simulating result shows that there are three kinds of breaking modes of marble under different confining stress and penetration; As well as the trend that specific energy consumption decrease first and then increase with the penetration increases, and there is optimal penetration to make specific energy consumption the lowest each confining stress. The optimal penetration and the lowest specific energy consumption are determined when confining stress range from 0 to 40MPa according to the simulation results.

Abstract: Discrete element model of fully sintering dental zirconia was constructed and calibrated. Based on the model, the dynamic process of low-speed milling of zirconia was simulated, and the effects of different cutting speeds, cutting widths and federates on the formation of surface cracks were also analyzed. Results show that residue cracks number and maximum depth increases significantly with increase of the cutting width, while the influence of cutting speed and federates is not distinct. That shows the possibility of high-speed machining on fully sintering dental zirconia with development of coating technology of cutting tool.