Abstract
The mechanical properties and fracture behaviour of concretes under different triaxial stress states were investigated based on a 3D mesoscale model. The quasistatic triaxial loadings, namely, compression–compression–compression (C–C–C), compression–tension–tension (C–T–T) and compression–compression–tension (C–C–T), were simulated using an implicit solver. The mesoscopic modelling with good robustness gave reliable and detailed damage evolution processes under different triaxial stress states. The lateral tensile stress significantly influenced the multiaxial mechanical behaviour of the concretes, accelerating the concrete failure. With low lateral pressures or tensile stress, axial cleavage was the main failure mode of the specimens. Furthermore, the concretes presented shear failures under medium lateral pressures. The concretes experienced a transition from brittle fracture to plastic failure under high lateral pressures. The Ottosen parameters were modified by the gradient descent method and then the failure criterion of the concretes in the principal stress space was given. The failure criterion could describe the strength characteristics of concrete materials well by being fitted with experimental data under different triaxial stress states.
Highlights
In practical engineering structures, concretes are inevitably subject to biaxial and triaxial stress states [1]
According to the test results obtained by different researchers, it was shown that the mechanical behaviour of concretes under triaxial loads was affected by many factors, such as the loading rate, stiffness of the testing apparatus and the measuring and testing techniques, such as the adopted loading mode and the friction-reducing means along the loading direction
This study focused on the mechanical behaviour of concretes under triaxial view and (b) side view
Summary
Concretes are inevitably subject to biaxial and triaxial stress states [1]. In order to accurately analyse and design these structures, it is necessary to study the mechanical responses and damage evolution characteristics of concretes under multiaxial compressive and tensile stress conditions [2]. Despite the difficult test system technology and the lack of uniform specifications, the mesoscopic modelling that demonstrated good robustness gives reliable and detailed damage evolution processes under complex multiaxial loadings This is helpful towards further understanding the triaxial mechanisms of damage evolution and the mechanical behaviour of concretes. Due to the heterogeneity of meso-concrete and the complexity of its internal structure, there are rare systematic and comprehensive numerical simulation studies of concretes under triaxial loadings, especially under the combination of unequal stresses of tension and compression. These simulations provided a foundation for establishing the quantitative relations between the macro-mechanical properties of concretes and the mesoscopic parameters of concrete components
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call