Research On Dynamic Load Identification Based On Inverse System

The dynamic load of acting on the structure is determined accurately, which is a key point of engineering to work. It's very important in engineering, because of the load can not be obtained through directly measurement in many case, which due to the complexity of the structure and the complex factors of actual conditions. During the progress of the science, the technology has been developed quickly in recently years, and has been developed a lot of feasible identifying methods. However, there are still many works to be solved.The dynamic load identification is known as theâ…¡nd inverse problem of structural dynamic, which is reconstructs the time history of the loads with the responses and the vibration system are known. In actual engineering, there is not enough useful information to reconstruct the force in the time domain; it must be a hard work because of the effect that due to the number of measuring points and actual environment. Researchers must use the limited data to select the measure points legitimately and improve the reconstruction pattern, as much as to adapt the environment and enhance the accuracy.In this thesis the dynamic solve with the finite element method is analyzed, and combining with the classic theory of force identification, the reconstruction pattern is improved which uses the specificity of the inverse system method in small damp system (the contribution of the current load to response is very small). The proposed method is neglects the weak items in iterative solution process and analyzes the ill-posed problem with reconstruct matrix, and then uses the regularization technique to solve the ill-posed problem.In order to verify the validity of method, numerical simulation is used on the cantilever model, spring mass model and plane truss model; the analysis results achieved the desire. In this process analyzes the factors that affect the response accuracy. The factors include that the noise, the sample time, the number and location of measurement points, and the loads. The results of numerical simulation identify the reconstruction pattern is effective and feasible.