03.12: Global structural modelling of space frame structures with consideration of joint behaviour: An integral analysis approach

Abstract

ABSTRACTThe effects of the behaviour of joints on the distribution of internal forces and moments within a structure and on the overall deformations of the structure are generally neglected [1]. However, where such effects are significant, they should be taken into account. Provisions are given in Eurocode 3, Part 1‐8 [2] for analysis, classification and modelling of joints with respect to rotational degrees of freedom. Provisions for translational degrees of freedom are missing.In shear connections slip may occur in case slip resistance is smaller than design load. This holds true for shear connections category A and B according to Eurocode 3, Part 1‐8 [2]. In structures with predominant normal forces such slip effects may accumulate and considerably affect the internal forces as well as the deflections. Structural modelling and calculation of slip effects is a complicated task in structural mechanics. In this paper, concepts are presented how to consider slip effects in joints when dealing with large space frame structures. Stick‐slip‐models are outlined and implemented in 3d structural models. Calculation techniques are discussed relating to the additional degrees of freedom (statically over‐determined systems) and the non‐linear behaviour.The importance and benefit of this integral analysis approach, where the effects of the joints are considered in the global modelling, are illustrated by the example of the Louvre Abu Dhabi Dome. The dome measures 185m in diameter and consists of approx. 11'000 steel members, most of which having shear connections. The results show that slip in joints must not be neglected in the global structural analysis. The quality and accuracy of the calculated results are verified by deflection measurements on site.