Multi-scale EFG model for Simulating Concrete Material

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Multi-scale EFG model for Simulating Concrete Material Qiang xu • Jianyun Chen • Jing Li

Received: 27 December 2011 / Accepted: 5 January 2012 / Published online: 18 January 2012 Ó Springer Science+Business Media, B.V. 2012

Abstract In this paper, a new multi-scale numerical model is presented using meshless element free Galerkin (EFG) method to simulate the multi-scale constitutive relation of concrete. The scale separation is based on the decomposition of the mesh free shape function into a and b scales, similar decomposition is also adopted for the constitutive equations. And the constitutive relations in different scales for concrete are established. The multi-scale EFG model is utilized for discretization of components of concrete block, which are aggregate, cement and transition region. The strengths of these components are adopted according to Weibull distribution. Consequently, the multi-scale EFG model is applied to describe the evolutionary processes of damage, the propagation of cracks and the characteristics of hysteresis of concrete. The plain static analysis of concrete block is performed by using this model and the calculated result is discussed. Q. xu  J. Chen (&)  J. Li School of Civil and Hydraulic Engineering, Dalian University of Technology, Dalian, China e-mail: [email protected] Q. xu e-mail: [email protected] J. Li e-mail: [email protected] J. Li State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian, China

Keywords Concrete  EFG  Multi-scale constitutive relation  Damage  Cracks  Hysteresis

1 Introduction The problem of scaling is of central importance in the research of concrete. In the field of structural mechanics of concrete, the study of scale effects is acquiring a prominent role, due to the need for a proper prediction of the mechanical properties in large-sized structures, based on the available test data of concrete in small scale. The theory and models in small scale for concrete have been developed significantly during the last 30 years and have been documented in an increasing number of publications. Although from a theoretical point of view the field has reached a stage where the developed methodologies are becoming widespread, the quantitative analysis of models in small scale of concrete is still a complex and difficult task. Many authors make the analysis for the model to simulate concrete in small scale (Wittmann 1989). Discrete microstructural models for concrete, such as random lattice models or random particle models, have established themselves as a powerful and realistic alternative to the no local continuum models for softening damage and fracturing. Because the grade and aggregate content of concrete have a direct influence

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on its trait of macro-dynamics, a suitable model of the aggregate concrete with high aggregate content is a precondition to successfully execute concrete mesomechanical simulation. (Yuncheng et al. 2007, 2006) executes a parallel numerical computation of the wetsieved concrete s