Buckling Restrained Brace Deformation Measuring Device

Abstract

Buckling Restrained Braces (BRB’s) have become common in seismic frames in earthquake areas. If a BRB performs as desired the steel core may yield but it is not easy to know the degree of yielding, or how much of the BRB earthquake life has been used up. To determine whether such a brace should remain as is, or whether it needs to be replaced, an inexpensive and simple measuring device that reports the deformations undergone is required. This paper discusses a study undertaken to develop such a device. Firstly, a literature study was undertaken and candidate devices were selected. Using Subjective Quantitative Analysis (SQA) and specific performance objectives the most appropriate of these was chosen. This device was then constructed and tested in a controlled environment. This mechanical device performed well through various stimulated earthquake cycles and events, is cheap, simple to install, and small. It provides cumulative and maximum displacement estimations and will be beneficial to the industry in post-event decision making.