Nondestructive Dynamic Evaluation of a Concrete Reaction Wall—Numerical and Experimental Studies

Abstract

Proper identification of the modes of vibration of a structure is crucial in order to avoid the condition of resonance under dynamic loading conditions. A combination of numerical simulation, physical experimentation, and waveform analysis was employed in order to obtain a dynamic evaluation of the reaction wall for the Network for Earthquake Engineering Simulation (NEES) large scale testing laboratory at Cornell University. The first four modes of vibration of the structure were identified, and this information is now available to researchers who design experiments that utilize the NEES facility. This paper presents the numerical (finite element) studies and a description of the impact test procedure used to excite and record the response of this massive, posttensioned, reinforced concrete structure. It also illustrates how numerical modeling aided in the design of experiments and how waveform analysis proved essential for the proper characterization of the dynamic behavior of this unusual structure.