Papers by Author: Ying Wu Fang

Abstract: An approach of numerical modeling and simulation algorithm is presented to predict dynamic behaviors of one kind of antenna radomes materials efficiently. Considering the dynamic behaviors in the lateral and interior of the antenna radomes materials, the dynamic simulation equations of the antenna radomes materials is established based on a dynamic boundary element method (DBEM) by using the domain reducing to decrease computational scale and costs of the equations greatly, and the dynamic behaviors of the antenna radomes materials can be gotten effectively. Numerical simulation calculating and experiments show that the presented method not only saves computational efforts, raises analytical efficiency and simulation accuracy but also can provide the theoretical bases for avoiding the weak pose of the antenna radomes materials. It has very important reference value for improving theoretical calculation and design level of the antenna radomes materials.

Abstract: In this paper, a numerical method is presented to determine the periodic response of hydrodynamic bearing-rotor system. The observed state information of the system is used to solve inversely the Jacobian matrix, and to trace the periodic response with the change of the control parameter. Jacobian matrix obtained is used to calculate the Floquet multiplier, so the stability of the periodic response can be determined by Floquet theory. The proposed method is applied to a rotor system with the elliptical bearing supports to solve the periodic response and determine its nonlinear stability. Validity of this method is illustrated by comparing numerical results with the traditional method.

Abstract: An analytical method of single field reducing-coupling on dynamic modeling is presented to analyze dynamic behaviors of thin plate structure based on dynamic fundamental solutions. In order to improve systematic modeling precision and efficiency, the method of single field reducing-coupling is introduced to deduce governing equations of thin plate structure dynamics by dynamic boundary element method (DBEM). The scale of matrix and generated time of coefficient matrixes are shortened greatly and dynamic behaviors of thin plate structure is obtained rapidly and accurately. The numerical examples and experiments show that the theory, established method and calculating program are feasible, and it has good precision and high efficiency.

Abstract: A method of systematic modeling was presented to analyze dynamic characteristics of an assembled thin plates structure. Based on dynamic fundamental solutions of a thin plate, governing boundary equations in the lateral and internal vibration of the thin plate are established by using a boundary element method (BEM). According to assembled conditions on the boundary, dynamic characteristics equations of the assembled thin plates structure are deduced. In order to raise calculating efficiency and avoid complicated programming operation, an approach of frequency scanning is introduced to analyze dynamic characteristics of the assembled thin plates structure. The natural frequencies and modal shapes are obtained fast and effectively. By numerical calculation and experiments given, the established method has not only good precision but also high efficiency.

Abstract: A soluble intralumenal stent for vascular anastomosis was prepared from glucose, Dextran-40 and heparin. The solubility of the stent was tested in vitro and in vivo. Animal tests were carried out with femoral arteries of rabbits. In comparison with the literature reported surgar and poly(ethylene glycol, PEG) stents, shorter dissolving time and higher patency (or survival) rate were obtained. Cell culture experiments suggested that the heparin containing glucose and Dextran-40 stent (H-sugar) had no irritation and toxicity to the endothelia cells. No thrombosis was observed from the in vivo tests in 2 months after the anastomosis. Such a heparin containing sugar stent is a promising candidate for fast sutureless anastomosis of vessels in non-trauma surgery.