Dynamic Deflection Characteristics Prediction And Experimental Analysis On The Beam Structure

The deflection of a bridge is commonly used as metric parameters for detecting the large bridge health status. Bridge vertical deformation curve can be obtained by measuring bridge deflection changes, and then determine the maximum deflection is in a safe condition.However, dynamic deflection measurement of bridge is limited due to lack of a reliable and effective dynamic prediction method in the present, so the detection method has been one of the hot problems in engineering circles. In this paper, simulation of beam structure’s deflection under various loads is analyzed with analytical analysis, finite element method and experimental analysis in order to seek a kind of method suitable for bridge dynamic maximum deflection testing. This method can guide the design and implementation of bridge dynamic deflection test system in the future.(1) Polynomial fitting model is researched on the simple and complex beam deflection. Both analytic and the finite element method are used to solve and analyze deflection curve and unit node deflection value under various load for the simple and complex beam. Then polynomial equation model is established about beam deflection by the polynomial fitting method. Compared with the theoritical value to analyze error, the results shows that beam interpolation polynomial model can be used as a description of simple and complex beam structure deflection model at a given maximum deflection precision requirement through the selection of beam position and the number of points.(2) Design optimization of Sensor number and location. Use acceleration sensor to test acceleration of beam interpolation, and then the frequency domain method to predict deflection of beam interpolation point is adopted. By the feasible direction algorithm, both the acceleration sensor number and position are optimized, and then model of beam deflection curve is obtained at a given precision requirement in5%.(3) The feasibility of beam interpolation polynomial model is verified by experimental analysis. Data acquisition software program is designed by VB language, and then the beam deflection test is completed to realize the maximum deflection prediction of beam by platform design.