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A1b: Reduced-Scale Reaction Frame

Area A1b houses a reduced-scale reaction frame for structural testing. The reaction frame consists of approximately 115 square ft (14.5 ft long x 8 ft wide) strong floor and an L-shaped reaction wall (side of which are 14.5 ft wide x 8 ft high and 8 ft wide x 8 ft high). On the strong floor and walls, holes (for ¾ inch bolts) are provided at a 8 inches on center are provided. The reaction frame is designed to be used with the two state-of-the-art loading and boundary condition boxes (LBCB) that are described below. It is also possible to use this self-reacting frame in other test configurations with actuators. The reaction frame is served by a 2-ton overhead jib crane. A dedicated hydraulic power supply line with a dual port (30 gpm each) Shore Western hydraulic service (HSM) manifold is also available.

Each LBCB is a self-reacting assembly of six actuators and swivel joints, with control software capable of imposing any combination of six actions (forces and moments) and six deformations (displacements and rotations) to test specimens connected to its loading platform. Each actuator is equipped with a servo-valve, a displacement transducer and a load cell for control and measurement. The overall dimensions of the LBCBs are 57 x 42.5 x 35 inches (W x D x H). The force and displacement capacities of the LBCBs in the Cartesian coordinates are given in the table below. The capabilities of LBCBs enable complex testing configurations using substructure schemes or multiple loading points on test specimens. LBCBs are mounted on L-shaped reaction walls at different locations and orientations based on the needs of testing configuration as shown below.


LBCB Capacity

DOF Displacement Force
x 3.65 inches 15 kips
y 3.65 inches 15 kips
z 1.51 inches 40 kips
Rx 7.1 degrees 40 kips-ft
Ry 7.3 degrees 40 kips-ft
Rz 15.6 degrees 19 kips-ft