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

Thesis (M. Eng.) - Asian Institute of Technology, 2012

There are many residual strain detecting methods at the present but none of them are suitable to detect residual strain of steel reinfor cement bar due to cost of experiment and reliability of results. This study mainly focused o n identification of relationship between the load {u2013} displacement curve of macro- hardness te st and residual strain of rebar. The extent of the past studies covers the interpretatio n of elastic properties, e.g. elastic modulus and yield stress, from load {u2013} displacement relationship by nano {u2013} indentation. However, no one has proposed the technique used for investigation of residual strain. This research fully based on the numerical simulation of the macro {u2013} indentation. The axisymmetric and the three dimensional finite eleme nt simulation are used to develop the relationship between load {u2013} displacement curve of i ndentation and material properties including residual strain of material. It is shown in this thesis that the best technique for interpretation of material elastic properties and r esidual strain is the characteristic relationship between load and displacement from ind entation test. In this research, there are shown the pattern of the load {u2013} displacement cu rves are changed with the direction of the indentation, the curvature of the surface and t he dimensions of test specimen. In detail comparison results of each case are presented in th is thesis.