Papers by Author: Zhong Yang

Abstract: The fatigue failure modes of reinforced concrete beams externally strengthened with basalt fiber reinforced polymer(BFRP) sheets was examined in an experimental and analytical study. One strengthened beam failed due to the debonding and fracture of U-wraps FRP sheet at the anchors,and the others failed the fatigue fracture of the longitudinal tensile reinforcements. Based on Code for Design of strengthening concrete structure, the fatigue failure of RC bending members strengthened with FRP was analysed,and the indicate that with reinforcement ratio of 0.612% and fatigue stress ratio of 0.3, only the fatigue fracture of steel bars occured rather than the crushing of concrete in the compression zone.

Abstract: Polyvinyl alcohol fiber reinforced cement-based composites are a new kind of material based on micro mechanics design. It is produced by adding polyvinyl alcohol fiber in the cement-based composites. In efforts to study the mechanical properties of polyvinyl alcohol fiber reinforced cement-based composites, some specimens were tested to examine performances. According to experimental investigation on mechanical properties, the stress-strain relationship curves and failure patterns are obtained. The test indicates that polyvinyl alcohol fiber reinforced cement-based composites have better toughness and fracture energy, and it has superior physical mechanical performance.

Abstract: Based on the calculation method of cracking load for reinforced concrete beam, the formula to calculate cracking load of normal section for concrete beams strengthened with BFRP sheet is established. The cracking load experiment of seven concrete beams strengthened with BFRP and three concrete beams strengthened with CFRP is conducted, and the results showed that fiber sheet layers and fiber sheet types have little effect on cracking load of concrete beams strengthened, the cracking load of beams strengthened mainly depends on the strength of concrete. The comparison between estimated values and test values of concrete beams strengthened indicates that the estimated values are slightly smaller, the formula can be used to calculate the cracking load of concrete beams strengthened.

Abstract: An optimum reticulated shell structure is selected and its dynamic properties are analyzed. In this paper analyses the dynamic feature and gains the elementary parameters from the analysis of free vibration. The frequencies and modes are compared by two finite element methods. The paper analyzes the dynamic responses of the reticulated shell structure subjected to two-dimensional and three-dimensional earthquake waves respectively. Simultaneously analyses the linear，geometric nonlinear and both geometric and material nonlinear dynamic responses in two situations. The nodal displacements and stresses of members are compared and analyzed. The characteristics of elastoplastic seismic responses of the structure are revealed and the basic rules are obtained.

Abstract: Reticulated shell is one type of the common spatial structure form. This paper proposes a vibration reduction method by supplementing viscous dampers in the reticulated shell. It analyzes the seismic performance on the optimum partial double-layer reticulated shell with dampers by ANSYS soft, gains the stress in the members and the nodal displacements, and compares the dynamic responses between the normal and vibration reduction structure. By means of different parameters, the rules of vibration reduction effect in the reticulated shell with viscous dampers are acquired. It is shown through the calculation that the method developed in this paper is efficient for the dynamic analysis of the reticulated shells.