A New Identification Method For Bidirectional Moving Vehicle Loads On Bridges

Moving force identification from dynamic responses is a very important problem for bridge design, also an important aspect of inverse problem in structural dynamics. In recent years, it's always one of the focuses in the international bridge and structured field, in which governments and researchers in the developed countries pay much attention. A new method which uses plate theory to identify bidirectional multiplevehicle moving loads is proposed in this paper.Firstly the research background and practical significance of moving force identification are expounde dand the present situation at home and abroad is introduced,then the research target and contents are pointed out simply in this paper.This paper introduces some existing methods which are used to identify moving force and the research situation in the inverse field both at home and abroad, assesses and compares with the advantages, disadvantages and scope of application related to these methods.Based on Hamilton principle, the mode superposition method, least-squares problem, and so on, the equation of motion of asimply-supported plate beam subjected to loads moving in opposite direction is established. Dynamic responses of each node in isotropic plate are obtained by means of analytical software ANSYS of FEM building the model of bridge structure. Based on dynamic responses data obtained from the numerical analysis by using ANSYS, a set of program used to identify moving loads is written in MATLAB. During the process of moving load, the influence of some parameters such as the number of vehicle, noise levels, load eccentricity, vehicle speed, sampling frequency, width-span ratio and measurement point arrangement are taken into account.Finally,some conclusion are made,a few related issues are also discussed and further studies are recommended.