Tension-Compression Damage Model with Consistent Crack Bandwidths for Concrete Materials

Wei He,Yu Cheng,Ting-Ting Fu,Peng-Fei Jia,Ying Xu

doi:10.1155/2019/2810108

Abstract

This paper proposes a tension-compression damage model for concrete materials, formulated within the framework of thermodynamics of irreversible processes. The aim of this work is to solve the following problems: the premature divergence of numerical solutions under general loading conditions due to the conflict of tensile and compressive damage bounding surfaces, which is a result of the application of the spectral decomposition method to distinguish tension and compression, and the unsatisfactory reproduction of distinct tension-compression behaviors of concrete by strain-driven damage models. The former is solved by the sign of the volumetric deformation, while the latter is solved via two separated dissipation mechanisms. Moreover, of specific interest is an improved solution to the problem of mesh-size dependency using consistent crack bandwidths, which takes into account situations with irregular meshes and arbitrary crack directions in the context of the crack band approach. The performance of the model is validated by the well-documented experimental data. The simplicity and the explicit integration of the constitutive equations render the model well suitable for large-scale computations.

Highlights

Concrete is still one of the most widely used construction materials in civil engineering applications [1]. erefore, developing an efficient constitutive model for concrete is of great importance since it contributes to engineering designs, failure analyses, and life-cycle assessments by reducing costs and time [2]
The mechanical behavior of concrete materials is mainly governed by the nucleation and growth of microcracks and their coalescence into macrocracks [3], which may result in the failure of a structure
It is an irreversible thermodynamic process accompanying energy dissipation and changes of the microstructure [4]. Such a progressive degradation of material properties can be phenomenologically described by models [5,6,7,8,9,10,11,12,13,14,15,16,17] based on continuum damage mechanics (CDM), which is generally accepted by the scientific and engineering communities [18]

Summary

Introduction

Concrete is still one of the most widely used construction materials in civil engineering applications [1]. erefore, developing an efficient constitutive model for concrete is of great importance since it contributes to engineering designs, failure analyses, and life-cycle assessments by reducing costs and time [2]. It should be noted that the crack band approach can only be regarded as a partial regularization method for mesh-size dependency in the sense that the objectivity of the energy dissipation is ensured [62], and the global structural response can be captured correctly [56], but the mathematical description of the rate boundary value problem (BVP) still remains ill-posed [63]. The objectives of this paper are fourfold: (i) to define the criterion distinguishing tension and compression by the sign of the volumetric deformation; (ii) to propose a model to describe distinct tension-compression behaviors of concrete materials under a framework similar to that of Cervera et al [11] and Comi and Perego [26]; (iii) to develop an improved estimation of the crack bandwidth using the projection method for solving the problem of mesh-size dependency; and (iv) to validate the proposed model by the selected benchmark tests

Tension-Compression Damage Model with Consistent Crack Bandwidths

Fracture Energy Regularization with Consistent Crack

Model Verification