Keerthana Kirupakaran

Indian Institute of Technology Madras | IIT Madras

This study investigated the effect of loading frequency on the fatigue damage process in concrete using digital imaging and acoustic emission techniques. It was found that the complex fatigue damage process in heterogeneous concrete is reflected in the amplitude of acoustic energy. The distribution of acoustic energy levels was utilized to classify...

It is well known to engineers that fatigue accounts for majority of material failures. Fatigue failure gets initiated at an internal flaw and is essentially a multiscale phenomenon wherein the microstructure of a material undergoes gradual and permanent changes. Although the nominal stress may be well below the ultimate strength of the material, th...

In this research, the fracture processes in concrete subjected to monotonic and fatigue loadings are characterized and the differences in failure mechanisms are studied using acoustic emission (AE) and digital image correlation (DIC) techniques. Experiments are performed on notched plain concrete beams under three-point bending. The micro and macro...

In concrete, it is well known that around the tip of a major crack, a fracture process zone (FPZ) exists wherein toughening mechanisms such as crack nucleation, micro-cracking and aggregate bridging occur. These processes in FPZ are responsible for its post-peak softening behaviour under monotonic loading. Behaviour of concrete under fatigue is mor...

A fatigue model for plain concrete under variable amplitude loading is proposed by unifying the concepts of damage mechanics and fracture mechanics through an energy equivalence, in conjunction with the principles of dimensional analysis and self-similarity. The effects of stress ratio and overloads that accelerate the crack growth rate is included...