Advanced Materials Research Vols. 243-249

Abstract: With the development of society, the demand of coal resources is increasing. However, the deformation and damage of buildings above goaf, which caused by underground mining, is getting worse and worse. Therefore, research and design of anti-deformation of buildings above goaf have certain positive role to deal with problems caused by mining deformation. This paper mainly discusses the double plate foundation used in buildings above goaf, and compares the anti-deformation effect of double plate foundation and strip foundation based on numerical ansys of the both.

Abstract: This paper describes the characteristics and construction processes of Multi-winged branches pile, it also introduces the basic principles and considerations should be followed in the design process by analyzing the mechanical properties of Multi-winged branches pile, and summarizes the calculation formula of bearing capacity for the single pile. This formula is suitable for Multi-winged branches pile and it can provide the reference for scientific research and engineering practice.

Abstract: Three large-scale concrete-filled FRP-steel composite circular tubes and a control steel tube were tested to investigate flexural behavior. The effects of FRP and composite with different types of FRP with various ultimate strains were investigated. The study demonstrated the important effect of FRP, and showed that the load-displacement curves of FRP-steel composite tube beams could be divided into four stages: elastic stage, plastic stage, hardening stage and residual stage. An additional decline stage was gained for multi-fiber with different ultimate strains and steel composite tube concrete beams. FRP could increase the ultimate bearing capacity and bring the hardening stage after steel tube yielding, and a certain degree of stiffness would be achieved to avoid the “zero stiffness”. The composite of a variety of FRP could relax fracture failure for the FRP-steel composite steel concrete beams, realized the successive rupture of fiber in batches and changed the failure modes.

Abstract: The characteristics of integral forced prformance for seel tubular high scaffold with couplers were introduced and deficiencies were pointed out in the paper. Integral forced prformance for steel tubular high scaffold with couplers was simulated by finite element software ABAQUS. Couplers joint was simulated with nolinear elastic spring element model. Eigenvalue buckling analysis was used to get the most stability capacity. The simulated result agrees well with previous experimental result.

Abstract: Thin-walled cylindrical shells are widely used in many industrial sectors as light structural elements. Determination of their buckling strength under various types of loading conditions is a crucial work for engineering design. Due to the needs of research of crashworthiness, dynamic buckling of cylindrical shells subjected to the strong axial impact becomes a frontier issue in recent years. The axial impact is a very complex dynamic process because of the coupling of multiple effects. In this paper, the buckling mechanism of cylindrical shells subjected to axial impact and the influences of boundary conditions, and energy absorption properties have been investigated by experiments.

Abstract: In this paper, non-coherent prestressed steel stranded wire being introduced in one concrete silo model of 10m inner diameter is tensed at both ends. The prestress losses of wires are tested. Based on the tested result, the trend of prestress losses and prestressing wires strain is educed.

Abstract: Five different full-scale improved beam-to-column connections in steel moment frame were tested to study the failure process, failure mode, strength and plastic deformation capacity. The speciments consisted of one Welded-Bolted Widen Flange-Dog Bone Connection(SP1-1), one Welded Widen Flange-Dog Bone Connection(SP1-2),one T-Widen Flange Connection(SP2),one Beam Strengthen-Flange Splice Plate Reduced Connection(Reduced depth=0)(SP3-1),one Beam Strengthen-Flange Splice Plate Reduced Connection(Reduced depth=50mm)(SP3-2). The test showed that the five connections effectively moved the plastic hinges away from the face of the column so that end welding of beam would be effectively protected, the ultimate plastic rotation of connection exceeded 0.03rad, ductility factor is large than 4 and hysteresis loop is full .these connections provided good plastic deformation and energy dissipation.

Abstract: A efficient 3D beam element based on the distributed nonlinearity theory is proposed for nonlinear analysis of reinforcement concrete structures. The sections consist of reinforcing steel and concrete in this formulation and the section stiffness matrices are calculated through the integration of stress-strain relations of concrete and the accumulation of reinforcing steel effect. The force-based formulation is adopted in the evaluation of the element stiffness matrix and the element state determination. The improved Kent-Park model is adopt for the stress-strain relation of concrete, and uniaxial stress–strain relationships proposed by Mander is introduced for reinforcing steel. Finally, the ultimate load of a cantilever reinforced concrete beam subjected to a lateral load was analyzed with the proposed formulation to illustrate its accuracy and computational efficiency.

Abstract: A new method for calculating the elastic lateral stiffness of the multi-ribbed composite slab by ANSYS—the layered-shell element method is introduced in this paper. In the modeling process, there are two ways for establishing the model using element SOLID46: the first refers to regarding the slab as a whole to make arranged layers. While the second type suggests that making arranged layers in each part already separated according to the materials. Especially when there are reasonable hypothesis, the analysis results can guarantee certain precision. By comparison among the two models and the experimental results, no errors with each other have exceeded 5%. The whole model is used for the numerical simulation in view of its briefness. Several factors affecting elastic lateral stiffness are considered, mainly including elastic modulus of the concrete, elastic modulus of the brick, and number of the ribbed-column. From the calculating results, conclusion can be deduced that all of these factors affecting the slab’s stiffness significantly. Along with the factors’ rising, the elastic lateral stiffness of the wall grows up. Basically, the influence factor and the elastic lateral stiffness of the slab present to be linear relationship. It is also meaningful to see that the elastic modulus of the brick plays a very important part in the elastic lateral stiffness of the wall. When compared to the SOLID65 and LINK8 used for the slab’s modeling before, the layered-shell element method is simple in principle, and distinct in conception. Above all, because only one type of element in the finite element analysis is used, it will cost less time when used on building a model of integrated architectural construction.

Abstract: The cold-formed steel member can arrange the most suitable shape of section according to the material needed. It can increase the load capacity and decrease the weight index when it is used for power transmission towers. The effect of cold-forming procedures to cold-formed steel members is different according to the thickness of steel plate or strip. The design method of cold-formed steel members considering the strength in Chinese code of cold-formed thin-wall steel is proposed when the thickness is less than or equals 6mm. In order to study the effect of cold-forming procedures on the strength of steel, the mechanical property tests are developed on flat plates, adjacent angles and angles, which are cut from cold-formed thick-wall lipped angles. According results of test, advices on improving the formula is proposed, which is used to design the member(t≤6mm) in China, and the design method of cold-formed thick-wall steel members considering their strength is proposed. These will provides technical supports that the cold-formed steel member can be used on power transmission tower broadly.