A 3D finite element model for reinforced concrete structures analysis

Abstract

This work presents a numerical model for 3D analyses through the finite element method of reinforced concrete structures subjected to monotonic loads. The proposed model for concrete is orthotropic and uses the equivalent uniaxial strain concept. The equivalent uniaxial stress-strain relation is generalized to take into account the triaxial stress conditions. The parameters used in the equivalent uniaxial stress-strain curve are determined from the failure surface defined in the principal stress space. The implementation in finite elements is based on the consideration of smeared cracks with cracks rotating according to the directions of the principal stresses. Also, an embedded reinforcement model was implemented to represent existent reinforcing bars. Finally, some results are compared with experimental data from the literature to demonstrate the validity of the numerical model developed.Keywords: reinforced concrete; finite element method; constitutive models; orthotropic model. Este trabalho apresenta um modelo numérico para análise tridimensional de estruturas de concreto armado submetidas a cargas monótonas. O modelo proposto para o concreto é um modelo ortotrópico e utiliza o conceito de deformação uniaxial equivalente. A relação tensão-deformação uniaxial equivalente é generalizada para levar em consideração as condições triaxiais de tensão. Os parâmetros usados na curva tensão-deformação uniaxial equivalente são determinados a partir da superfície de ruptura definida no espaço de tensões principais. Também, implementouse um modelo de armadura incorporada para representar as barras de armadura. Por fim, apresentam-se resultados comparativos com ensaios experimentais e analíticos para demonstrar a validade do modelo numérico. Civil and Environmental Engineering, Federal University of Pernambuco, giuliana.franca@gmail.com, BR 104, Km 59, S/N, Nova Caruaru, Caruaru, Pernambuco, Brazil b Graduate Program in Civil Engineering, Federal University of Rio Grande do Sul, americo@ufrgs.br, apacheco@ufrgs.br, Av. Osvaldo Aranha -99, 3º andar, 90035-190, Porto Alegre, Rio Grande do Sul, Brazil Received: 07 Feb 2011 • Accepted: 03 Jun 2011 • Available Online: 07 Oct 2011 Abstract Resumo Palavras

Large diameter shafts for underground infrastructure

“…Babu et al (2005), in a review on concrete constitutive modelling, describe the generalized use of the Ottosen failure criterion in practice. The failure surface corresponding to this criterion is given by the following equation (Bono et al, 2011):…”

“…3D moment-thrust interaction diagram with an external point projected inside the 2D diagrams.where r 1 , r 2 , r 3 are respectively the major, intermediate and minor principal stresses.Therefore the Ottosen failure criterion requires the determination of five constitutive parameters for the concrete, namely: f c , a, b, c 1 , c 2 Bono et al (2011). also describe correlations recommended by the CEB-FIP model code from 1990 for these parameters based on the ratio between the tensile and compressive uniaxial strengths (k).…”

Damage and plasticity evolution of reinforced concrete beams using laminated Euler-Bernoulli finite elements

“…The second problem is related to the famous work of Bresler and Scordelis [13], who tested many reinforced concrete beams with different cross-sections and for many kinds of reinforcements. Many models were developed [14], [15], [16] aiming to reproduce the experimental results of Bresler and Scordelis [13].…”

Multiple Linear Regression Modelling for Predicting Building’s Short Columns Loads under Gravity

“…In general, the short columns of hill buildings attract more forces and undergo extensive damage if it is not properly designed for earthquake forces. The using of 3D finite element models to investigate the behaviour reinforced concrete and steel structures have been the subject of many studies in the last years [11][12][13][14]. The finite element analysis of reinforced concrete (RC) structures under different conditions can be a powerful tool for predicting their behaviour in order to evaluate the safety levels of design.…”