Strain Modal Numerical Simulation And Experimental Studies Of Large-scale Steel Beam

Steel structure beam is widely used in bridges and buildings, and even some pure steel structure bridges and buildings, such as overpass,gymnasium and so on. If the design of steel beam is not appropriate and the method of using it is wrong, or the deformation and injury of the structure that is caused by the environment and external factors may cause very serious consequences, even the whole structure collapsed or destroyed. It is very difficult for us to observe the actual vibration and subtle structural changes before the structure completely destroyed. The damage of structure may be directly caused by resonance and crack. So based on the simple study of bending and load bearing of steel beam, we need to study the structure vibration characteristics and local stress concentration problems.Modal analysis technique is a good way to solve it, and the strain modal is better than the traditional displacement mode. So the strain modal analysis is a very good method for the steel structure beam. Because steel structure materials is isotropic, so we can simulate the vibration and strain distribution of it. But in the laboratory the beam for the experiment is relatively small,can only do some simple research. So this paper selects the large scale steel structure beam that more close to the practical engineering, and simulate the strain mode parameter mathematical model of it, at last it is verified by experiment.The main work is briefly mentioned as follows.According to the strain modal analysis and mechanical vibration theory, we can get the strain response mode model of the large scale steel structure beam,and introduced a variety of strain mode parameter identification in frequency domain method.The simulation of large scale steel structure beam was discussed in this paper.Do the strain mode test, large scale steel structure beam strain frequency response function matrix is actually measured, and calculate displacement and strain mode parameter of large scale steel structure beam.Strain modal experiment and theoretical solutions are compared, it verify the strain modal parameter identification in frequency domain method is correct. Finally the work of this paper is summarized, and a series of significant ideas of future are proposed.