engleski

Numerical modelling of tension influences in 3D reinforced concrete structures

This paper presents combined fracture-plastic model for concrete based on the modified Rankine and Mohr-Coulomb material laws with special attention given to the behaviour of reinforced concrete structures exposed to the dominant tension influences. This model employs Rankine failure criterion based on the orthotropic smeared crack formulation. Softening is defined by linear function which describes increase of tension stresses in the direction perpendicular to the crack plane. Stiffness matrices of concrete after propagation of one and two cracks are presented. The material nonlinear behaviour of reinforcing bars is described by 1D elasto-visco-plastic model. The problem is solved by finite element method using composite 3D elements which consists of 20-nodes brick elements and embedded 3-nodes line elements. The reinforcing bars represented by 1D finite elements are defined by second order space function. Developed numerical model is implemented into computer programme PRECON3D which is tested on a few examples and the obtained results shows good agreement with the known numerical and experimental ones.

reinforced concrete; nonlinearity; 3D material model; fracture; softening of concrete

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