Applied Mechanics and Materials Vols. 351-352

Abstract: The flexural behavior of concrete beams reinforced with CFRP-PCPs composite rebars was studied. Experimental results showed that the performance of CFRP-PCPs composite rebars beams is superior to that of CFRP beams at service and ultimate and comparable and even better than RC beams at service condition. Flexural cracks of concrete beams reinforced with CFRP-PCPs composite rebars are hairline before prism cracking, and they widen after the prism cracking Keywords: CFRP-PCPs, composite rebars, beam, flexural

Abstract: In order to investigate the seismic performance of zipper frames, three 10-storey structure models, including a zipper frame with tension zipper columns, a zipper frame with weak zipper columns and a chevron braced frame, were designed. Some indexes, including the natural periods, steel consumption and dynamic response under frequent and rare earthquakes, were analyzed and compared. The results show that, the dynamic responses of the three structures are similar to each other and all of them can meet the requirement of no-damage under frequent earthquakes and no-collapse under rare earthquakes provided by the GB50011 code, but the steel consumption for the zipper frames is less than that of the chevron braced frames, indicating the comprehensive seismic performance of the zipper frame is better than the chevron braced frame. However, it is also found that the design method of the zipper columns is conservative and a more reasonable design method of the zipper columns is needed to be provided.

Abstract: The elementary unit of the optimization system for steel structure is optimization group. The optimization system takes advantage of the inheritance and polymorphism of VC++ to optimize the members with different amounts of variables or using different codes concurrently. The structure of the introduced system has good adaptive capacity of increasing optimized sections, as well as adding or updating codes. The constraints setting of the system can be adjusted according to the steel structure codes of different regions, which are mainly based on prevailing Chinese codes at the current phase. The system uses an advanced complex method which makes the result of optimization easier to be used in practical engineering since being available for discrete variables.

Abstract: Hybrid coupled shear wall with steel coupling beams has often been used as load-resisting system of high-rise buildings under lateral loads. However, joint between steel beam and shear wall is under combined and high stress. Reinforcement details of the joint are very heavy. This study addresses the effect of shear wall cement composites type in hybrid wall system on the seismic performance of steel coupling beams embedded in shear wall. The main test variables were the failure mode of steel coupling beam and types of cement composites, such as PSH2C and concrete, for shear wall.

Abstract: Assembly box concrete hollow floor sructure is a new-style whole structure that are constituted by the a cross section of a concrete box composed of small prefabricated components (concrete superposition box) and a cast-in-place concrete rib beam.The internal force distribution law was analyzed in this paper, based on the static load experiment with a multi span column-supported assembly box concrete hollow floor.The findings prove that the prefabricated boxs and cast-in-situ concrete ribbed beams are able to form a whole to jointly bear external forces, that the internal force distribution law is basically the same with the solid cast-in-situ concrete floor with no beams, and that the floor structure can be simplified to the column strip and middle strip.The specific distribution ratios between the minus moment and the plus moment of the column strip and middle strip respectively are as follows. For the angel area floor(contianed edge beams), the ratio of midspan section is 0.537:0.463, the ratio of support section is 0.816:0.184; for the edge area floor(contianed edge beams), the ratio of midspan section is 0.51:0.49, the ratio of support section is 0.808：0.192; for the inner area floor, the ratio of midspan section is 0.55:0.45, the ratio of support section is 0.75:0.25.

Abstract: In the present paper is given the calculation of the two-layer and the single-layer beam models on an elastic basis with variable and constant modulus of subgrade reaction. The two-layer beam is the beam of variable rigidity, the lower layer simulates the foundation, and the upper - the structure, at the same time is considered the weight of each layer. In the results of calculations of beams, as the two-layer and the single-layer, the values of the internal forces and stresses are obtained more with variable modulus of subgrade reaction than with constant. With consideration of the two-layer and the single-layer beam models with the same characteristics of the base, the values of internal forces, generated in two-layer beams, are obtained much more.

Abstract: This study focuses on the following: analysis of the basic mechanical properties of freeze-thaw cycles BFRP composite; freeze-thaw cycle on BFRP reinforced concrete structures force performance; provide experimental basis for the the basalt FRP freeze-thaw environment concrete structure andtheoretical support.

Abstract: By mean of the energy functional variational principle and considering shear lag effect of flange, the dynamic governing differential equation for the I-section cantilever beam in the action of compressive load P at the member end is obtained. The equation is solved by the separation variable method. According to the weigh residual method, the relation between natural frequency coefficient and critical load coefficient as well as the flutter critical load coefficient are made, the influence of shear lag effect on natural frequency coefficient and critical load coefficient is discussed.

Abstract: To evaluate the seismic behavior of precast reinforced concrete (RC) shear wall with steel boundary components, two pieces of prefabricated RC wall panels are tested quasi-statically under different axial compression forces. Both panels performed larger ductility than requested by the current seismic design code. Finite element model is then constructed to investigate the function of steel boundary components. The model is first calibrated by the experimental results. The strength, stiffness, and crack development all agree well with the phenomenon observed from experiments. Then the area of steel angle is changed as the main parameter to affect the seismic performance of RC wall panels. It is observed that the strength and ductility of a panel with steel boundary components are larger than that with common rebar boundary elements.

Abstract: Here individual anchored strength of prestressed end with local area under pressure was studied through experiment, the damaged mechanism of local area under pressure was discussed. The ferrule effect of peripheral concrete upon the concrete under local pressure loading is not obvious.