Numerical investigation of crack growth in concrete subjected to compression by the generalized beam lattice model

Abstract

The beam lattice-type models, such as the EulerBernoulli (or Timoshenko) beam lattice and the generalized beam (GB) lattice, have been proved very effective in simulating failure processes in concrete and rock due to its simplicity and easy implementation. However, these existing lattice models only take into account tensile failures, so it may be not applicable to simulation of failure behaviors under compressive states. The main aim in this paper is to incorporate Mohr-Coulomb failure criterion, which is widely used in many kinds of materials, into the GB lattice procedure. The improved GB lattice procedure has the capability of modeling both element failures and contact/separation of cracked elements. The numerical examples show its effectiveness in simulating compressive failures. Furthermore, the influences of lateral confinement, friction angle, stiffness of loading platen, inclusion of aggregates on failure processes are respectively analyzed in detail.

Modified generalized beam lattice model associated with fracture of reinforced fiber/particle composites

“…There are mainly two kinds of numerical algorithms for simulating fracture process in heterogeneous brittle media such as concrete: event-driven method [10,11] and load-stepping method [13]. In the former, the load discretization is adjusted to capture every elemental failure.…”

“…Otherwise, if the size of the simulated specimen is not very large and the main aim is to observe the failure process in more details, another kind of GB lattice is preferred, in which a single aggregate covers dozens of nodes [10]. The simulations in this paper are mainly based on the latter.…”

“…Until now, the media investigated using lattice-type models are mainly particle composites [7][8][9][10]. Nevertheless, fibers and rebar are another two common kinds of inclusions in many engineering composites such as concrete.…”

“…The Mohr-Coulomb criterion is widely accepted to describe elemental failing behavior under various loading conditions. Therefore, the GB lattice model improved in [10] can simulate a wider range of fracture experiments in principle.…”

“…The GB lattice model proposed recently was employed to simulate tensile failures by adopting maximum tensile stress failure criterion at first [9]. Then it has been improved to investigate compressive failures by using the Mohr-Coulomb criterion [10]. The Mohr-Coulomb criterion is widely accepted to describe elemental failing behavior under various loading conditions.…”