Numerical investigation for the design of rectangular concrete encased steel composite columns

Advanced design methods are becoming more important for the structural analysis. However,
their results depend strongly on the quality of the numerical model and its underlying
assumptions. Current Eurocode 4 does not provide clear guidance for this analysis type.
A literature review on the compression tests conducted on concrete encased steel composite
columns is presented. It was found out that there is a lack in the literature when it comes to the
testing of slender composite columns as opposed to numerous tests done on stub columns. A
selection of existing specimen tests are then simulated using finite element analysis software
ABAQUS. Nonlinearity in the model was defined through materials and geometry. The interface
modelling between steel and concrete as well as the modelling of load introduction are discussed.
The finite element model was intended to be as generic as possible so that it can be taken as a basis
for future parameter studies. Moreover, the column resistance check using interaction curves was
discussed. Different approaches to form interaction curves namely strain limitation and plastic
section capacity were compared.