Numerical analysis of ultimate load and crack propagation in a concrete beam with longitudinal small hole

Abstract

This analytical study aims to investigate the flexural behavior of simply supported RC beams having longitudinal hole with circle cross section under monotonic two point loads. The commercial FE program ABAQUS was used for simulating and implementing the specimens behavior that tested experimentally in previous researches. The overall specimens investigated were thirteen RC rectangular beam specimen, the first one was solid while the others with longitudinal circular hole. The specimens with holes divided into three groups, each one has a specified hole diameter 25 mm, 40 mm, and 50 mm. The distance from center of hole to the top section face was variable where the hole would be completely in the stress block, below it, or partially within it. The validity of the simulated model were verified by comparing the available load deflection data with the implemented one, where good agreement were noticed. The simulated models could introduce the ultimate load, first cracking load and its propagation in addition to the maximum attended deflection. It is concluded that the existence of a longitudinal hole with a percentage of diameter to beam depth ratio below 20% with different positions from top surface of the cross-section to the center of the hole values caused decreasing in ultimate load not exceeding 5% compared with the solid beam.