An efficient approach of modelling the flexural cracking behaviour of un-notched plain concrete prisms subject to monotonic and cyclic loading

• Published in: Engineering structures Vol. 51; pp. 36 - 50
• Main Authors: Hamad, W.I., Owen, J.S., Hussein, M.F.M.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.06.2013; Elsevier
• Subjects: Applied sciences; Building failures (cracks, physical changes, etc.); Building structure; Buildings. Public works; Concrete structure; Concretes; Constitutive relationship; Construction (buildings and works); Cracks; Cyclic loading; Cyclic loads; Damage detection; Digital image correlation; Durability. Pathology. Repairing. Maintenance; Exact sciences and technology; Fatigue (materials); Fictitious crack; Fracture mechanics; Mathematical models; Plain concrete; Prisms; Cyclic loading; Constitutive relationship; Fictitious crack; Digital image correlation; Plain concrete; Constitutive equation; Vibration; Digital image; Experimental study; Modeling; Displacement; Monotonic load; Failure analysis; Cyclic load; Concrete construction; Numerical simulation; Application; Crack
• ISSN: 0141-0296; 1873-7323
• DOI: 10.1016/j.engstruct.2013.01.007

► Experiments on un-notched plain concrete prisms subject to monotonic and cyclic four-point bending. ► The fracture process is monitored using digital image correlation system. ► A numerical model based on the fictitious crack approach is developed. ► The model predicts the degradation in stiffness and approximates the CMOD. ► A computationally efficient modelling technique. In the field of vibration-based damage detection of concrete structures efficient damage models are needed to better understand changes in the vibration properties of cracked structures. These models should quantitatively replicate the damage mechanisms in concrete and easily be used as damage detection tools. In this paper, the flexural cracking behaviour of plain concrete prisms subject to monotonic and cyclic loading regimes under displacement control is tested experimentally and modelled numerically. Four-point bending tests on simply supported un-notched prisms are conducted, where the cracking process is monitored using a digital image correlation system. A numerical model, with a single crack at midspan, is presented where the cracked zone is modelled using the fictitious crack approach and parts outside that zone are treated in a linear-elastic manner. The model considers crack initiation, growth and closure by adopting cyclic constitutive laws. A multi-variate Newton–Raphson iterative solver is used to solve the non-linear equations to ensure equilibrium and compatibility at the interface of the cracked zone. The numerical results agree well with the experiments for both loading scenarios. The model shows good predictions of the degradation of stiffness with increasing load. It also approximates the crack-mouth-opening-displacement when compared with the experimental data of the digital image correlation system. The model is found to be computationally efficient as it runs full analysis for cyclic loading in less than 2min, and it can therefore be used within the damage detection process.