Implementation of the sandwich model in the numerical Framework Compas FEA

Author: Benjamin Berger
Language: English

Abstract

Compas FEA is an OpenSource software package that enables the communication between CAD Software solutions (e.g. Rhinoceros) and finite element programs (e.g. Ansys, Abaqus) that are familiar in practice. In this master thesis, the sandwich model is implemented in the Compas FEA.

The sandwich model is used to design reinforced concrete plates subjected to general combinations of bending and twisting moments as well as membrane and transverse shear forces. Based on the Compas FEA, the structure is subdivided into shell elements, and the internal forces are determined by assuming linear-elastic material behaviour. The sandwich model is used then for dimensioning each individual element. According to the sandwich model, the shell element should be divided into two sandwich covers and a core. The sandwich covers are assumed to carry the membrane forces and the bending and twisting moments. The transverse shear forces are resisted to the core.

The structure is modelled in the CAD program Rhinoceros and the calculation process is carried out automatically. All results are displayed directly in Rhinoceros. The algorithm was tested on simple loading condition as was on larger structures. The results were checked for plausibility and compared against the solution from the commercial Software package Axis.

The sandwich model is now available as an OpenSource plug-in for the Compas FEA for free use.