Papers by Author: Yun Xu

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: The experimental study and finite element analysis of RC beams strengthened with CFRP board are introduced in this essay. Test research of six beams stuck with CFRP board on their tension faces has been carried out on rigidity by contrasting with three non­strengthened beams. Three specimens are primary loading beams and the others are secondary loading beams, the calculating formula for the short-term rigidity on the section of concrete beams strengthened with CFRP board has been established. Calculation is carried out on short-term deflection of RC beams strengthened with CFRP board subjected to primary load and secondary load. The results indicate that the RC structure can be strengthened effectively by sticking with CFRP board, so that the expansion of crack and rigidity of beam can be controlled especially, and the experimental results compared with those predicted by the formula in resemblance.

Abstract: On the basis of the Generalized Beam Theory (GBT), this paper presents an elastic analysis of the distortional critical stress of cold-formed thin-walled lipped channels in combined compression and minor axis bending. The results obtained using the exact analysis presented herein have shown excellent agreement with previous available results. And the accuracy, validity and effectiveness of the presented solution were demonstrated. The calculating process was displayed by an example which can give reference to the research and design. This paper will contribute to the understanding of distortional mechanics in thin-walled members.