Papers by Keyword: FEM Calculation

Abstract: For decades attention has been paid to interaction of foundation structures and subsoil and development of interaction models. Currently there are several software that, can deal with the interaction of foundations and subsoil. The purpose of this paper is to compare resulting deformation of the slab, subsidence of the subsoil, bending moments and contact stress calculated by two different software based on FEM calculations. Calculated deformation of the slab is compared with deformation measured during experiment.

Abstract: A series of torsion tests under different temperature were carried out with circumferential notched cylindrical rock specimens. By this kind of specimens, mode III rock crack propagation in real meaning was realized. The initiation torsion M of the mode III rock crack was measured under different temperature. The variation law of M v.s. temperature T was obtained. The initiation stress near crack tip under different temperatures was calculated by finite element method, and then, the mode III fracture toughness K_IIIC of the rock was obtained by further calculation. The experiment and numerical results show that the mode III fracture toughness of the rock decreases with the temperature increase. The results of the paper can be used in the design of deep underground engineering ,disaster prevention and mitigation engineering.

Abstract: The growth of a crack in a bi-materials base under a building will cause the structure failure. The mechanism of this kind crack growth must be investigated. In this paper, a series of I-II mixed mode crack fracture experiments for bi-materials have been conducted. In some situations, a crack can grow from the weak medium concrete into the hard medium marble under compression load. The stress intensity factors KI ,KII and the first principle stress σ1 near crack tips have been calculated. The difference in crack propagation ability between the single-material and the bi-materials specimens are also studied. The experimental results are in accordance with the σθmax fracture criterion.

Abstract: Ductile fracture process includes three stages: void nucleation, their growth and coalescence. The voids nucleate due to the fracture or separation of non-metallic inclusions and secondary-phase particles from the material matrix. Micromechanical models based on the Gurson plastic flow criterion are often used for analysis of ductile fracture. They consider the material as a porous medium in which the effect of voids on the stress-strain state and plastic flow cannot be neglected. Another important property of the Gurson criterion is that the hydrostatic stress component influences the plastic flow of the material.