Effect of Material and Geometrical Parameters on Peeling Rip-off Failure – Numerical Study

• Main Authors: Arsalan Khan, Mohammad, Haider Rizvi, Zarghaam, Panda, Shradha
• Format: Conference Proceeding
• Language: English
• Subjects: Cohesive Zone Model; Composite interface; Peeling; Retrofitting
• ISSN: 2214-7853; 2214-7853
• DOI: 10.1016/j.matpr.2018.06.300

Steel or FRP plates are adhesively bonded to the external faces of RC beam as a popular technique of retrofitting,; for example, to enhance or improve the load capacity of a beam subjected to an increased traffic load or experiencing a material deterioration with age. However, the overall behaviour of such retrofitted beams is effected by the formation of undesirable cracks, leading to premature failure such as plate debonding and peeling. At this, the designed capacity of plated beam gets significantly affected. While researchers have developed empirical models, fracture mechanics based models and design proposals, the large chunk of which comes from laboratory experiments, yet the capacity of beam under such undesirable modes of failure cannot be accurately predicted due to complex nature of material properties and geometrical discontinuities involved. The experimental work is seen to be restricted due to funding reasons that could accommodate testing of beams over significant number of combinations of material and geometrical parameters involved in practice, as well as to test the effect of boundary conditions. Therefore, it is now proposed to address this problem through a robust numerical tool models validated through literature available against a variety of laboratory experiments. The aim of such tool models would be to predict both the desirable as well as the undesirable modes of failure, and compared with the some design recommendations available on the choice of range of parameters (such as, plate width to thickness ratio). Peeling being considered as the catastrophic mode of failure, the study focuses on the behaviour of particularly this mode of failure and categorising their defining or controlling factors/parameters. It is identified that, like debonding, peeling can also be controlled through a right selection of parameters that significantly affect formation and propagation of flexural crack at plate end to lead to peeling. For example, shorter and/or thicker plates promotes peeling; and higher flexural strength and fracture energy of concrete can avoid peeling.