Study On Structural Hybrid Testing Method With Shaking Table

In the seismic research of large modern structures, shaking table testing can only be carried out for small-scale models because of the limitations of the table size and loading capacity. The testing precision cannot meet the requirements due to the dimensional effect of testing model. Structural hybrid testing method for shaking table can be used to effectively overcome the limitation of loading capacity on the size of testing models. In this method, the whole structure is divided into two parts, consisting of the numerical substructure with simple mechanics characteristic simulated on the computer and the physical substructure with complicated mechanics characteristic carried out phsical testing on the shaking table. The action of numerical substructure on physical substructure is simulated by the actuator in order to meet the boudary conditions of physical substructure. Thus, the testing for large-scale model can be achieved. The application area is extended for shaking table testing. The testing precision is also improved. The real seismic action can be simulated on the shaking table. This method has distinct advantage in the research for specimens with multiple degrees of freedom or distributed mass.Several contents are investigated in this dissertation, including the principle of structural hybrid testing method for shaking table, the setup of the software and hardware syste, the numerical integration method, and the time-delay compensation. In addition, the real-time substuctural testing and structural hybrid testing for shaking table are respectively carried out using one-story frame structure as physical substructure. The main contents are as follows:1. The structural hybrid testing method for shaking table is put forward with displacement control. The principle and the process of the testing are also investigated. Two kinds of vertical boundary condition simulation method are presented for physical substructure. The displacement control method can make full use of the characteristics of the actuator, and be beneficial to improve the testing stability and precision. The feasibility of displacement control is proved for hybrid testing method by testing research.2. Based on the MTS system, the structural hybrid testing method for shaking table is put forward. The control of testing equipment and the numerical integration can be realized by the MTS station. The testing results show that the established hybrid testing system for shaking table can achieve the complicated testing according to the setting by the testing personnel.3. The modification of the inertia force is implemented for the Operator Split (OS) algorithm. The explicit numerical integration algorithm is investagated for the hybrid testing for shaking table. The stability of the algorithms is analyzed when the specimen is mass-spring-damper system. The results show that the damping ratio and the mass ratio of specimen have great influence on the stability of the algorithms.4. Considering sepcimens with mass (inertia force) and without mass, the real-time substructural testings are carried out based on the MTS system of hybrid testing for shaking table, respectively. The influence of the mass is analyzed on the stability and precision of real-time loading testing.5. The first hybrid testing for shaking table in mainland China is implemented about one-story frame structure. The feasibility of the testing method is also validated. Through several testings in many cases, it demonstrates that the applied loading control testing system and method, the numerical integration algorithms and the time-delay compensation method are effective and feasible.