Experimental Verification Of Operator-splitting Method For Dynamic Substructure Testing

The structural aseismic test is an important method to study the aseismic performance of structure,but the traditional methods of aseismic test have defects,which cannot reproduce the real state of structure in earthquake.The real-time substructure test divides the structure into the numerical substructure and the experimental substructure,which can reproduce the velocity of test specimen.The real-time dynamic substructure experiment which is commonly used in experiments of TLD and TMD is developed from the real-time substructure experiment.And the influence of the mass of the experimental specimen on the test counterforce is considered during the loading of the experiment.One of the key factors affecting the success of the real-time substructure experiment is to choose the correct integration algorithm,so it is of great significance to study the real-time integration algorithm with good stability and high accuracy.Under this condition,the algorithm characteristics of operator-splitting(OS)method of dynamic substructure test are studied and verified by experiments.The main results are listed as follows:(1)The OS method of dynamic substructure is introduced,and the performance of the algorithm is further verified by numerical simulation analysis.The results show that the mass ratio in the system of single freedom degree has an influence on the stability of the unmodified dynamic OS method,and has no effect on the stability of the modified dynamic OS method.At the same time,the algorithm accuracy of the modified dynamic OS method is better than that of the unmodified dynamic OS method.The dynamic OS method used in multi degrees of freedom area is conditionally stable,and its stability is jointly determined by multiple structural parameters.(2)The specific implementation method of the dynamic substructure test based on the MTS system is studied.It is verified through hybrid simulation that the MTS system can independently complete the dynamic substructure test.A time-delay compensation method based on the dynamic OS method is proposed to ensure the acceleration and speed of the experimental substructure during loading.This time delay compensation method has achieved good results in both hybrid simulation and experimental verification.(3)Multiple real-time hybrid tests are completed to verify the performance of the dynamic substructure OS method,including the single degree of freedom test with the test substructure of pure mass,the single degree of freedom test with the test substructure of mass spring system and the two degree of freedom test.The experimental results show that when the mass ratio of the single degree of freedom system is greater than 1,the unmodified dynamic OS method diverges,while the modified dynamic OS method remains stable and close to the exact solution.And under the parameters of this article,the stability of OS method,in the multi degrees of freedom system,decreases with the increase of the mass ratio.At last,the accuracy of the algorithm decreases with the increase of the mass ratio in all experiments.The experimental results are consistent with the theoretical analysis results,indicating that the dynamic OS method is effective.