Papers by Author: An Zhi Yan

Abstract: A new semi-active MR-TMD control device, which is consisted of TMD which take the gasifier as the damper mass and a magneto-rheological damper, was proposed to solve the problem of factory building vibration when the gasifier is working in it. The feasibility and effectiveness of semi-active MR-TMD control system for structural vibration control under rectangular periodic excitations were simulated and analyzed by adopting one semi-active control algorithm proposed by the author. The control effect of semi-active MR-TMD, passive TMD and active AMD were compared by adopting the same model structure. Numerical simulations show that the damping performance of using semi-active MR-TMD control is better than that of using passive TMD control and active AMD control; the displacement and acceleration of the structure’s each floor have decreased significantly. It also indicates that the semi-active controlling method is available.

Abstract: Many Literatures pay attention to the location and parameter optimization of Tuned Mass Damper (TMD). Yet there are few studies on the case where both the TMD and the main system have plastic impacts under large stroke of TMD fixed in limitation space. A two degree-of-freedom (DOF) vibratory system having symmetrically placed rigid stops and subjected to periodic excitation is considered in this paper. The equations of the vibratory system are constructed, and then for simplification the dimensionless equations are obtained. Poincaré map was used to study the relationship between the motion stability and parameters. Period-doubling bifurcation of motion was found by numerical simulations. With the gradual change in excitation frequency, the routes of quasi-periodic impact motions to chaos are observed from simulation results.

Abstract: The paper presents a numerical investigation of mixed-mode crack induced failure of concrete beam strengthened with steel plate. Both the cracking of the concrete and concrete-steel interfacial debonding can be observed. There is a shear stress concentration at the pre-existing crack or debonding tips, which is the root cause of the debonding. The results indicate that debonding only initiates and propagates along the left interface to the steel plate because that the normal stress along the left interface is tensile which make considerable contribution to the debonding and the normal stress along the right interface is compressive.