A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Structural Engineering, School of Engineering and Technology

Thesis (M. Eng.) - Asian Institute of Technology, 2015

In order to make the structure safe during seismic vibration, t he structure can be strengthening by using different kinds of bracing system. If ordinary brace is used for this purpose, it will be buckled under lateral compressive load. This study will investigate the performance of the cylindrical wedge - type non - comp ressive bracing system. The whole experimental investigation has been done into two main phases: p reliminary test and final test. A 9mm bar has been tested by UTM for preliminary test. Furthermore, in the first phase of final test , total six specimens of 1 2mm diameter have been used for uniaxial experiment. In the second phase, the test has been performed by applying cyclic load through the hydraulic actuator on a half portal frame. The cylindrical wedge grip worked properly under compression by releasing the sacrificial steel, which prevent buckling of steel core. The hysteretic loops from tension load are not stable in size and slope even the same load. It is anticipated that non - linearity from the device itself or from the gripping device of the universa l testing machine may cause this unstable hysteresis. The developed device needs some improvement to use in the inclined configuration. Pre - loaded spring as well as the improvement in steel casing for perfect alignment of both wedge and steel core might re solve problem from inclined configuration.