This paper explains how to use nonlinear finite element analysis (NLFEA) for determining the reinforcement design for a concrete structure, which also complies with the Eurocode 2 (EC2) and fib Model Code 2010 (fib2010). Since nonlinear finite element analysis (NLFEA) is fast enough and used in designs on regular basis now, it is important to relate the conventional design methods to this newer design method.
The design of a common and simple structure (a pile cap) is checked using NLFEA according to the rules of the EC2 and the fib2010. A script has been used to set up a parametrized model of the pile cap. The strut-and-tie model is automatically generated, which will be found is much more realistic than when one would use the rules of the EC2 to set up the strut-and-tie model. The forces of the strut-andtie model are extracted from the FE-model, and an automatic reinforcement process is started in the NLFEA. Checks are performed on the governing stresses and strains.
Some important differences will be explained and the extra information from the NLFEA is shown to be very useful. This implies mainly the definition of the internal arm Z and the effect of stiffness of the pile or foundation supporting the structure, resulting in better description of the actual failure mechanism.