OpenFresco-Based Seismic Hybrid Testing Method

In view of the hybrid testing method can disclose the seismic performance of structures accurately and economically, the method has been used worldwidely and plays more and more important roles on seismic investigation nowadays. However, the numerical substructures are normally simulated with simple linear models, and the accuracy of testing results will be greatly reduced if elastic-plastic deformation occurs in the structures when suffering a strong earthquake. For solving this problem, this paper proposes to simulate numerical substructures by using the professional finite element software. This paper proposes the hybrid testing method by using the finite element software OpenSees and interface software OpenFresco, and validates the effectiveness and accuracy of the proposed hybrid testing method numerically and experimentally. The main contents of this paper are as follows:Firstly, the OpenSees-dSpace hybrid testing method and the OpenSees-Labview- dSpace hybrid testing method, with the OpenFresco as interface software, are proposed. It is shown that the OpenFresco can successfully transfer data with the finite element software OpenSees and control device dSpace or Labview in the proposed methods.Then, the effectiveness of the proposed method is investigated by hybrid simulations. It is shown by the hybrid simulation results that the communications among OpenSees, OpenFresco, and dSpace/Labview are very reliable, and excellent hybrid simulation results are obtained from these two methods.Finally, the stability and accuracy of the proposed hybrid testing methods are validated through actual tests. It is shown from the one storey frame structural model that these two hybrid testing systems behavior excellent performance in terms of stability and accuracy, and the results of the OpenSees-Labview-dSpace method are not as good as the OpenSees-dSpace method. Three storey frame structural model test results show that these two methods can work well together for performing the tests with multiple experimental substructures, and provide perfect test results.