Applied Mechanics and Materials Vols. 166-169

Abstract: Based on the Voronoi diagram of some nodes, the natural element method (NEM) constructs the shape functions by the natural neighbor interpolation method, and its shape functions satisfy the Kronecker delta property, which makes it impose essential boundary conditions easily. Based on the geometrical nonlinear relations and material nonlinear constitutive relations, we extend the NEM to material and geometrical bi-nonlinear problems in this paper. Numerical examples show that the NEM is effective, rational and feasible in dealing with problems of both material and geometrical bi-nonlinear.

Abstract: A nonlinear 3D solid model of hybrid coupled wall system with steel boundary elements has been founded by using FEM software ABAQUS to study its hysteretic behavior under cyclic loading, which considering the geometric large deformation and materials nonlinearity. To verify the efficiency of the model, two specimens with various coupling ratios of 30% and 45% are analyzed, and the results of analysis are compared with test ones. As the bearing capacities of both agree well in different loading stages, so the FEM model has enough accuracy and could be used to study the seismic behavior of hybrid coupled wall system with steel boundary elements. In addition, the results show that this new system dissipates energy by shear deformation of steel beams along and plastic hinge deformation at the bottom of wall, so it has better seismic performance.

Abstract: The safety of dynamic characteristics plays a very important role of underwater structures today. In this paper, in order to analyze the dynamic characteristics of structures we have done several groups of experiments and tested the dynamic characteristics of the models in air and water respectively，then we calculated the natural frequency of the suspended-span structures in water using Additive Mass Method and compared with the experimental data. The results showed that the comparison between the experimental and calculated data is accordant, contemporaneously we tested the natural frequency in water with in air to the same specimen , it shows that the frequency of structure in water is lower than in air, but only little difference.

Abstract: Abstract. Two full-scale specimens of angles steel using H-section member had been conducted. The specimens were subjected to cyclic reversal loading simulating earthquake effects on a steel moment-resisting force. The objective of the work is to determine the behavior of these connections under cyclic reversal loading well into the inelastic range and to ascertain the effect of design parameters such as column flange stiffener, pre-tension of bolts and the angles flange thickness on the overall behavior. Observations were made concerning the response of the connections and its elements in terms of strength, stiffness and energy dissipation. Information on the design of these connections is presented. The hysteretic behavior of angles beam-column connections under cyclic loading is presented in this paper. Rotational stiffness, the carrying capacity and ductility of top-seat angles connections are analyzed. It is concluded that angles connections can possess the relative high stiffness, strength and excellent ductility as moment-resisting components in the seismic design of frames. Most of the input energy was dissipated in the flange of angles while the column participated a little in the energy dissipation process in the test.

Abstract: CL (composite light-weight) building structural system is a new composite shear wall structure, which is light, good integrity, excellent seismic performance, insulation and structure of the body of the same life, good fire performance, increased use of area, and other advantages, this paper studies the structural properties of CL on the basis of case through the construction of affordable housing in advantages in the application.

Abstract: Discrete complex method is used in genetic algorithm(GA) and a mixed genetic algorithm called complex genetic algorithm(CGA) is formed. The complex method used here increases the quality of species groups, and improves the searching efficiency. The mixed genetic algorithm method is used in the shape optimization for mixed discrete variables. The integration and coding of the shape variables and the cross-section variables in genetic algorithm can not only solve the coupling problem of two kinds of variables, but also avoid the partial optimum solution resulting from the separation of the two kinds of variables. The result of the exemplification indicates that the complex genetic algorithm for structure shape optimization design of mixed discrete variables is effective.

Abstract: Friction-type high-strength bolt connectors are widely used in steel structure. However there has only general description for connection plate surface treatment method in the current Chinese design standards. Some research tests have been designed for different connection plate surface treatment method, which include different painting thickness and different blasting method. The results show that different treatment method has different anti-sliding coefficient. The anti-sliding coefficient would decrease with the surface coating thickness increase. The anti-sliding coefficient would less than 0.50 which the Chinese design standard required when some surface treatment methods are used, such as using steel wire section or using mixture of steel wire section and steel shot to sand blasting. So procedure qualification test is necessary to guide processing in order to ensure the quality of the products. It has certain conference value for practical engineering.

Abstract: The analysis rule of geometry composition analysis in building structure must rely on geometry theory, while the traditional Euclidean geometry theory can not solve some building structures problems of the geometry components. This problem can be solved in the use of projective geometry theory. In this paper we introduce the proof of projective geometry in the geometry composition analysis and we discuss the application of this theory.

Abstract: The pre-stressed concrete composite slab, which combines the advantages of cast-in-place slabs and precast slabs, has promising development prospects. In the paper, according to structural integrity, bond performance, sound insulation, thermal preservation and construction techniques, four categories composite slab, such as the composite slab with flat bottom panel (including the composite slab with bar truss reinforced precast concrete bottom panel), the concrete composite slab with precast ribbed panel, the composite slab with hollow bottom panel and the composite slab with sandwich bottom panel are studied. The composite slab with flat bottom panel has poor structural integrity, and its bond performance and crack resistance of edge joint details need to be improved; the composite slab with bar truss reinforced precast concrete bottom panel has enough bond force, but its storage and transportation are inconvenient; the concrete composite slab with precast ribbed panel has good structural integrity and convenient construction procedure; the composite slab with hollow bottom panel and the composite slab with sandwich bottom panel have functions of sound insulation and thermal preservation, however they are inadequacy to resist bending moment and have complex construction procedure. The concrete composite slab with precast ribbed panel is provided with good mechanical behavior, economy and practicability, and is worth further researching and promoting.

Abstract: Wind-induced dynamic analysis for flat tensegrity structure is performed with the nonlinear random simulation method in time domain. And several parameters such as wind velocity, length-windth ratio, rise-span ratio and prestress of cable are considered.