Failure Analysis Of Concrete Research Articles

Three-dimensional concrete impact and penetration simulations using the smoothed particle Galerkin method

In this paper, we model the three-dimensional concrete impact and penetration problems using a stabilized meshfree method. The present method is established using a non-residual penalty term from strain smoothing as a means of stabilizing the meshfree nodal integration method under the Galerkin framework. As a result, the meshfree discretization leads to a dual stress point algorithm with the stabilization parameterized by a measure of a local length scale. An adaptive anisotropic Lagrangian kernel is considered in junction with the stabilized meshfree formulation for the severe deformation analysis. In order to avoid the spurious damage growth and material self-healing in concrete failure analysis, a bond-based failure criterion is introduced. A frictionless self-contact algorithm is also developed to model the interaction between concrete debris in damage. Several impact examples are investigated including the study of scabbing and perforation of concrete under high velocity impact. The numerical results are compared with the experimental data to demonstrate the effectiveness of the present method.

Elastoplastic Damage Modelling and Failure Analysis of Concrete in Compression

Elastoplastic Damage Modelling and Failure Analysis of Concrete in Compression

New Damage Variable in Failure Analysis of Concrete

Cracking, i.e. material separation at the moment of fracture, is inherently an irreversible process and, hence, is synonymous with material damage. In failure analysis of concrete at increasing applied load, the degree of irreversibility, i.e. material damage, must be capable of being readily quantified by experimentally measurable or mathematically defined quantities. This paper shows the development of a new damage variable to analyze the failure process of a body concrete material, which has an aspect ratio of 2.5, at monotonic uniaxial compression up to the peak load carrying capacity, σc,u. This damage variable is derived from the intrinsic characteristics of the microcrack propagation within the bulk concrete material. It is readily quantified by the experimental stress and strain data of a uniaxial compression test to ultimate failure. It possesses the predictive capability to define the degree of damage accumulation within the bulk concrete material at any stage of the applied loading.

Heterogeneous Hardening Plasticity Model for Concrete

A heterogeneous hardening rule is proposed for concrete in this paper. Being different to the hardening rules in common use, by which the development of the subsequent yield surfaces from the initial yield surface is at an uniform rate with respect to the variation of the hardening parameter, the heterogeneous hardening rule deems that the development of the subsequent yield surfaces is at a nonuniform rate with regard to the change of the hardening parameter. Based on this hardening rule, a loading function including the effect of the hydrostatic pressure on the behavior of concrete is constructed. A simple and effective heterogeneous hardening plasticity model employing the associated flow rule is established for progressive failure analysis of concrete. With this model, the inelastic contraction and dilatation behavior of concrete under compression or tension-compression stress states can be successfully represented. The model has been applied to the analysis of some available experimental data and good correlations are obtained between the analytical and experimental results.

Tensile Tests and Failure Analysis of Concrete

The tensile strength of concrete is receiving an increasing amount of attention since the loading capacity and durability of structures are being studied more thoroughly, and since nonlinear fracture mechanics and numerical methods require a complete stress deformation relation. The theoretical background of the application of the tensile strength of concrete in fracture analysis is given. Test results are presented that were obtained from deformation‐controlled uniaxial tensile tests under static and cyclic loading of lightweight and normalweight concrete. The results have been used to establish material models for finite element calculations. Numerical examples show the usefulness of these models for static and cyclic loading conditions.