Applied Mechanics and Materials Vols. 353-356

Abstract: Finite element model of the main building of Zhaoguan coal preparation plant was established and its modal analysis was carried out based on ANSYS. The front six orders natural frequencies and modal shapes were calculated and the vibration characteristics were carried out. Results of modal analysis showed that the front six orders natural frequencies of the main building are between 1.7252 Hz to 5.1332Hz, which are far less than the working frequency of vibrating screen 15 Hz, so that the resonance phenomenon would not exist in the main building of the coal preparation plant.

Abstract: This paper mainly studies the distribution characteristics of surface wind pressure on low-rise buildings. Based on the theory of fluid dynamics, this study uses CFD software Fluent 6.3.26 to conduct numerical simulation of the models in wind tunnel tests by Yong Chul Kim involving four working conditions of different spacing or area density in regular arrangement. Compared with data of wind tunnel tests, the results show that different spacing or area density has significant influence on surface wind pressure of low-rise buildings and surrounding buildings have shielding effect over target buildings.

Abstract: In this paper, we revisit the problem of identifying the orientation of polygons. After reviewing previous work, we develop further insight into the problem. We then claim that, for a orientable simple polygon, a relationship between the orientation and the sequence of extreme vertices can be found. Building upon this relationship, a novel method is then presented, proved by apagoge, and tested. For the polygons containing circular arc, which the traditional algorithm does not work, a topological preprocessing is developed. The ideas proposed in this paper are simple and effective when used in industry. Experimental results are presented that demonstrate its practicality and efficiency in the manufacturing industry.

Abstract: This paper first introduces the units which are used in general-purpose finite element analysis software ABAQUS simulation of steel and concrete as well as their material constitutive models, and then taking the simulation analysis of a spiral staircase for instance to draw displacement of a spiral staircase along the outer edge lines, the inner edge lines, and the axes of the stair treads under static loadings. By comparison, we find the rationality and insufficient points of the simplification of the spiral staircase to the calculation assumption which makes the axle wires as rod pieces. According o the displacement and stress of the spiral staircase, we give some suggestions to provide some useful references to the designers of the spiral staircase.

Abstract: Using the finite element code ABAQUS and taking account of the wind load reduction, this paper presents a set of construction simulation methods of concrete cooling towers. A natural draft cooling tower at Taishan nuclear power station in Guangdong province, China, under three speeds of construction is simulated. Displacement and stress distributions of the cooling tower in the different construction stages are obtained. Some interested parts of the cooling tower are analyzed in detail and the variations of displacements and stresses of these parts with the construction are concluded. A comparative study of the influence of construction speed on displacements and stresses is performed as well. The analyses and proposals of this paper may be used as reference to the cooling tower design and construction.

Abstract: To mines turning from open pit to underground mining with caving method as transition, air leakage of overburden layer in winter can lead to lower pit temperature, affecting their regular production. The paper is based on the theory of fluid flow in porous media, simulating wind velocity of overburden layer air leakage with FLUENT software and calculating influence of air leakage of the overburden layer on pit temperature under the condition of various porosities and thickness. The conclusion is drawn that overburden layer thickness is above 40m,air leakage influence on pit temperature is relatively little, thus offering scientific basis for rational overburden layer thickness and structure of open pit into underground mining.

Abstract: In this paper, in order to study the wind interference effect,with change of height of the upstream building, the numerical simulation of the downstream construction disturbance of wind pressure distribution has been done. With architecture of upstream, wind pressure coefficient values of windward and leeward faces of downstream building basically reduces,and interference effect shows shielding effect.

Abstract: Cracking damage is a common phenomenon in large-scale concrete structure. But for the underground structure it is not permitted because crack will cause heavily damage and other disasters. With the aid of finite element method for deformation and stress field simulation, a detailed study is carried out for a large area foundation slab of an underground parking lot. The foundation soil condition and the hydrogeological condition are the principal influence factors that result in the cracking problems. The simulation results illustrate that the combined effects of foundation settlement and larger groundwater pressure cause the foundation slab cracking and the existence of expansive soil indeed exacerbates the problem.

Abstract: Based on the properties of curvature connection and theory of differential geometry, a sufficient condition of curvature connection between two adjacent surfaces is obtained, and then a new method of curvature connection of surface patches around a common vertex is put forward by using these conditions and consistency. As a result, the obtained surface patches have the lowest degrees, whose degrees are five, and the relevant system of equations can be solved easily.

Abstract: Structural connections are among the most essential parts in prefabricated concrete structures and good-quality design of connections is one major key to a successful prefabrication. A new horizontal wall-to-wall connection way for precast shear wall systems, which have been attempted in the field of modern residential buildings in China, is presented in this paper. An abaqus-based nonlinear finite element (FE) analysis under monotonic loading is implemented in order to understand the seismic performance of the proposed connection way of precast shear walls in comparison with that of the cast-in-place connection way. From the numerical results, it is concluded that the seismic performance of the presented connection technique, such as the deformability and the energy-dissipation capacity, is not weaker than that of its cast-in-place counterpart.