Strength Predictions of Normal Concrete Beam with Corner Notch

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Concrete beam are made by mixing aggregates, water and cement of typical design strength of 30–40 MPa to perform excellent bending resistance, usually tested under flexural test. Presence of notch in concrete beams is associated with stress concentration at the notch tip and reduces its load-carrying capacity. Strength predictions of beam made from concrete is not straightforward due to complex failure morphologies, but advancement of computing technology has led to evolution numerical modelling approaches within finite element analysis (FEA) framework. Modelling of crack is extremely complicated as notch tip exhibited singular stress to require very finely mesh around the crack tip. Incorporation of a constitutive model driven by energetic approach simplifies the modelling technique to perform strength prediction independence of mesh refinements. A traction–separation relationship can be incorporated to perform strength prediction of concrete beam with stress concentration. The main objective of the current project is to perform strength prediction of concrete beam with corner notch with a variation of concrete mixture following experimental work performed by Zhang and Liu. Extended Finite Element Modelling (XFEM), Cohesive Zone Modelling (CZM) and Virtual Crack Closure Techniques (VCCT) techniques were employed to perform strength prediction work using traction–separation relationship. The material properties used in constitutive model were independently determined as reported in the respective literature. 2-D modelling was idealized to take into advantage of geometry symmetries and self-similar behavior cracks using ABAQUS CAE Version 6.14 where meshing was refined at the vicinity of the notch tip. Good agreement predicted from XFEM result contributes by incorporating actual crack path following experimental observation reported from the literatures. Less good agreements from CZM and VCCT techniques were obtained where the simplified crack path as a straight-line was modelled, not accordance to actual crack path as modelling restrictions.