Calculation of benchmarks with a shear beam model

Abstract

Fiber models for beam and shell elements allow for relatively rapid finite element analysis of concrete structures and structural elements. This project aims at the development of the formulation of such elements and a pilot implementation. Standard nonlinear fiber beam formulations do not account for shear effects and cannot capture all failure modes (like shear failure) and hence cannot be used in the assessment of structures with shear problems, as it may result in large overestimations of ultimate carrying capacities. This issue has been remedied by a shear-sensitive fiber beam formulation developed at Universitat Politècnica de Catalunya, BarcelonaTECH (UPC) (Ferreira 2013). This 1D fiber beam model accounts for bending-shear force interactions enabling nonlinear, time-dependent and strengthening analysis of shear critical concrete frame structures. The model acts as an alternative and/or reference to plane stress and solid nonlinear FE models for usage in practical engineering. The reduction of calculation time and degrees of freedom and the few required input variables are advantages of the 1D model. In this project, this shear-sensitive fiber beam model will be inserted in the software DIANA and extended to plate/shell elements. This report relates to the preliminary analysis and validation of the fiber beam model with calculation of benchmarks with the original software CONSHEAR (UPC) and comparison with plane stress models in DIANA and with beam elements in DIANA. The objective is to compare the various analyses between them and with the available experimental results, cross-validate and conclude about the performance of the shear-sensitive beam element and set main goals of enhancements in the future implementation in DIANA software.