Non-linear FEM Analysis of 2D Concrete Structures

摘要

In this report a finite element program for analysis of reinforced concrete two-211u001edimensional structures, i.e., disks, slabs and shells is developed. Models for 211u001edescribing the biaxial non-linear constitutive behavior of concrete are 211u001epresented. Cracks are introduced when a given tensile strain is reached. A high 211u001eshear retention factor is kept in the crack surface making possible rotation of 211u001ethe principal stresses. New cracks are introduced if the tensile capacity is 211u001ereached in another section. The shear stress in each crack surface is limited by 211u001ea modified and reduced Coulomb criteria. If the limit is reached, plastic shear 211u001esliding occurs. In compression, a non-linear stress/strain relationship is 211u001eapplied. The concrete compressive strength of cracked concrete is reduced as a 211u001efunction of the tensile stress perpendicular to the crack surface.