MUST-SIM Overview

The Multi-axial Full-scale Substructure Testing and Simulation (MUST-SIM) facility at the University of Illinois at Urbana-Champaign is part of the National Science Foundation (NSF) George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES). In this facility, full-scale structures or structural subassemblages may be subjected to complex loading and deformation states at multiple connection points on the structural specimen, including the connection between the structure and its foundation. The MUST-SIM facility has the following unique features: (i) 6-DOF load and position control at multiple connection points, (ii) system modularity to allow for expansion and low-cost maintenance/operation, (iii) multiple dense arrays of non-contact measurement devices, and (iv) advanced nonlinear analysis, visualization, and data archiving and manipulation capabilities to enable integrated data exchange and manipulation, hybrid simulation, remote control and observation, and multi-site collaboration within a networked environment.

The MUST-SIM facility has three large modular six-DOF Loading and Boundary Condition Boxes (LBCB) that allow for precise application of complex load and boundary conditions. In addition to interactive local or remote control, the LBCBs can impose motions on structural specimens that are determined from the results of concurrently running numerical models of the test specimen and the surrounding structure/foundation/soil system through employing hybrid simulation. Additional actuators available within the Newmark Structural Engineering Laboratory (NSEL) enable additional loading and deformation to be imposed on the structure in a synchronized fashion with the LBCBs, enabling loading patterns such as interstory deformation or intraspan gravity loading. Dense arrays of state-of-the-art, non-contact instrumentation allow near real-time model updating for the model-based simulation. An array of multi-media client portals enable both local and remote access to streaming data during a test or playback of archived data from the NEES/Central data repository.

In addition to the large facility, NEES @ Illinois is equipped with a fully-functional 1/5th scale laboratory. This laboratory includes a 1/5th scale reaction structure with three 1/5th scale LBCBs, dedicated controllers, and a half-ton overhead crane. Reseachers are given the opportunity to conduct pre-test verifications with various load and displacement scenarios through the use of the small-scale facility. The small-scale laboratory is essential to the operation of the large-scale facility in that it allows users to understand the capabilities and limitations of the laboratory and the control systems prior to conducting experiments using the large facility. It has also proven to be a great learning experience to students as they are given hands-on experience in all aspects of experimental research.

Principal components and information flow in the MUST-SIM Facility

Examples of how the results obtained from experiments carried out in the MUST-SIM facility are useful to the research community include: (i) reliable establishment of performance limit states that take into account the structure, foundation and soil characteristics that will aid in the accurate assessment of existing structures, as well as in development of a new generation of structural systems and performance-based design guidelines, (ii) refining/updating existing analytical models and establishing new models can be facilitated through knowledge-based concepts that depend on learning from test results, (iii) the experience gained by use of the advanced dense instrumentations is valuable to other experimental testing programs, and (iv) the collaboration, control, and visualization modules developed may be extended to include loss assessment models, hence they can be used to portray overall loss scenarios before and after the application of remedial measures for seismic loss reduction.