Development and validation of an integrated software framework for hybrid simulation

Abstract

Hybrid simulation combines numerical and experimental techniques to simulate the response of structures. In the last two decades, notable developments have been made to make hybrid testing platforms modular and versatile. The OpenSees-OpenFresco software framework for hybrid simulation is a typical example which can interface with various control software and hardware. This paper presents the development of a robust integrated hybrid testing software framework at the National Laboratory for Civil Engineering, Portugal, which uses the National Instruments real-time and FPGA hardware. The software framework has a LabVIEW-based control and interface application for conducting hybrid tests using OpenFresco middleware. The OpenSees finite element software is also integrated into the framework and communicates with the middleware via a TCP/IP protocol. The software framework is designed to conduct slow to real-time hybrid tests assisted by a predictor-corrector algorithm which enables continuous movement of an actuator. It is also equipped with error tracking and delay compensation algorithms. New simulation tools can be simply added to it due to its modular and flexible nature. The capabilities of the software framework are first examined through simulated hybrid tests. It is then validated by conducting hybrid test of a two-bay one-story steel moment-resisting frame by physically testing one of its exterior columns.