An Experimental and Analytical Investigation of Mixed Mode Fracture on RCC Beams

Abstract

Fracture mechanics should be considered essential in the design of important structures such as bridges, offshore oil rigs and dams. The present work is an attempt to study the effect of mixed mode fracture on RCC beams by conducting experimental and analytical investigation. Four RCC beam specimens with notches at different locations were casted and subjected to three-point bending test in universal testing machine to determine the effect of mixed mode fracture on RCC beams. Apart from this, variation of stiffness of the beam with respect to crack length was determined. The same beams were modeled and analyzed analytically using ANSYS software. The results of both experimental and analytical investigation were compared to validate the study. Based on the experimental and analytical investigation, it is observed that mode I fracture occurred in notches provided at the center of the beam and at a length greater than critical length from the center of the beam, whereas mixed mode fracture occurred in the case of notches provided at a length less than or equal to the critical length from the center of the beam. Stiffness degradation was observed with increase in length of cracks and loading.

Keywords: Mixed mode fracture, Stiffness degradation, Notched beams, Fracture mechanics