Facility
The RTMD Testing Facility (or NHERI Lehigh Experimental Facility) has the capabilities to perform real-time testing using the effective force method, pseudo-dynamic testing method, or the pseudo-dynamic hybrid testing method for the testing of large-scale structural components, structural subassemblages, and superassemblages under earthquake excitations. The laboratory includes a strong floor that measures 31.1m x 15.2 m in plan, and reaction walls up to 15.2 m in height. Anchor points are spaced on a 1.5-m grid along the floor and walls. Each anchor point can resist 1.33 MN tension force and 2.22 MN shear force. Additional steel framing is used in combination with the strong floor and reaction walls to create a wide variety of test configurations. A 178-kN capacity overhead crane services the test area and an adjacent fabrication area. Additional smaller cranes with capacities of 45-kN and 27-kN also serve this area. The hydraulic system, combined with the dynamic actuators and a real-time digital servo-control system, enables real-time strong ground motion effects; sustainable for up to 30 seconds. The facility also supports multi-site pseudo-dynamic hybrid testing.
The equipment portfolio and resources of the RTMD facility include:
Five channels of dynamic loading, with the system configured for up to 8 channels and control by using either displacement or force, consisting of two 2050 kN dynamic actuators ported for three 400 gpm servovalves, +/- 500 mm stroke, and three 1500 kN dynamic actuators ported for three 400 gpm servovalves, +/- 500 mm stroke.
Ten three-stage 1500 liters/min (400 gpm) high flow-rate servo-valves.
Hydraulic distribution lines and service manifolds, with a low-pressure and high-pressure setting, to operate at 20.7 MPa (3000 psi) with a maximum flow of 1500 liters/min (400 gpm).Surge tank and three banks of accumulators that will enable strong ground motion effects to be sustained for up to 30 seconds. Each bank will consist of twelve 114-liter (30 gallon) accumulators, to supply a total accumulated oil supply of 4090 liters (1080 gallons).
Hydraulic system modifications, to connect the accumulators to the pressure line of the existing system, add dedicated connections for the new, high-flow hydraulic service manifolds, add a new return line from these dedicated connections to the pump house area, and add a new hydraulic oil reservoir in the pump house area for the oil needed to fill the accumulators and to receive the return flow, as well as make connections of this reservoir to the existing reservoirs, heat exchangers, and pumps.
Two hydraulic control systems with real-time hybrid control packages, with each channel of the controller designed to follow an independent, random load, or displacement history.
Teleobservation system including a system of digital high quality video cameras, network video cameras, flexTPS video server and Data Turbine data server.
Simulation system combination of a MATLAB/Simulink based host workstation and xPC Target real-time systems which apply the algorithms that generate commands for actuators. The Simulink real-time systems synchronize data channels from the control system and data acquisition system with simulation data and triggers camera snapshots aligned with simulation data.
High speed 304-channel data acquisition system, capable of acquiring data at 4000 Hz (4000 samples per second) per channel and expansion to 384 channels.
Data Repository system with data lost risk mitigation protocols.
Gigabit Ethernet ready computer laboratory with Internet2 capabilities.
Full machine shop and material testing facilities available through ATLSS Center and Lehigh University.
Below is the RTMD IT and Hardware Infrastructure.
