Development of the UPRM Hybrid Simulation Facilities: Substructuring Techniques Coupled Numerical Simulations

Abstract

Hybrid simulation is an innovative experimental method currently being tested and utilized for the simulation of earthquake loads on structures. The reliability of this experimental method will be achieved as more research targeting realistic conditions of structures (e.g. subassemblages and structures at larger scales) with more complex configurations are conducted. Furthermore, these studies need to address the efficacy of hybrid testing to simulate the collapse of structures. The University of Puerto Rico at Mayaguez (UPRM) is developing a hybrid simulation facility with its first-stage consisting of a two channel MTS Flex Test 60 control system with quasi-static hybrid simulation capabilities. The main objective of the UPRM hybrid simulation facility is testing of more realistic models of prototypes subjected to dynamic loads. The research is also focused on substructuring techniques: development, implementation and error measurement. At first, the hybrid facility will be calibrated with the analysis and hybrid testing of a 3-story 2-bay moment resisting steel frame subjected to the Canoga Park time history. Hybrid simulation with substructuring allows the modeling of parts of the structure we can predict analytically and testing other parts of interest at the laboratory. In this case, only the exterior column of the first and second story column of our prototype will be tested at a 1:3 scale while the rest of the structure will be modeled analytically using the software OpenSees and OpenFresco. Coupled numerical simulations were conducted of current partitioning strategies including the conventional and pinned substructuring techniques. These numerical studies showed that there is a need for better partitioning methods. The problem with the studied substructuring techniques is that they approximate the response of the prototype when they do not fully enforce compatibility and/or equilibrium in all degrees of freedom at the boundaries of the partitioned structures trying to simplify the experimental substructure.