Keywords: aluminium girder, FSW welding, ultimate behaviour, non-linear FEM, virtual experiment.

The use of aluminium alloys in bridge engineering represents a new trend: the aluminium that can lead to an economical design due to the great weight-to-strength ratio and corrosion resistance. This inspired the Japanese Aluminum Association to start developing an orthotropic deck system made of aluminium alloy [1].

The base elements of the deck are the extruded aluminium alloy profiles that are connected in the transverse direction of the bridge by the recently developed technique called Friction Stir Welding (FSW) [2]. Since the effect of this welding method had been partially known only, several topics have had to be investigated in order to achieve a deck system and a design method that are eligible in practice. In this, particular efforts were made by the analyses of the transverse behaviour of this deck, by investigation of an FSW-welded girder, which is focused in this paper.

The paper determines the possible numerical modelling way with the FEM-system MARC [3]. Non-linear finite element method is applied: geometrical as well as material non-linearities are considered. Different geometrical models, support conditions, material models and load conditions are applied. In this way, several details are investigated. Computational methods are tested and an accurate and efficient one is determined.

In order to obtain practically applicable numerical models, ultimate behaviour experiments have been virtually done, considering the certain details in a different modelling level. The results are compared with real static test ("pilot-test").

After all, the effects of FSW, material modelling, load conditions and geometrical modelling are evaluated and adjusted. The models that are accurate and efficient enough are found, which models – in their scope – promise the easiest acceptable way in modelling the entire deck, as well.

1

Okura, I., "Prospect of Application of Aluminum to Bridges", Japanese Society of Light Metal, 59th symposium, 19-31, 2000.

2

Nicholas, E.D., "Developments in the friction stir welding of metals", Proceedings of ICAA-6, Aluminium alloys, Vol. 1, TWI, Cambridge, 1998.

3

"MARC Volume A: Theory and User Information, Version K7", MARC Analysis Research Corporation, USA, 1997.

purchase the full-text of this paper (price £20)

go to the previous paper
go to the next paper
return to the table of contents
return to the book description
purchase this book (price £125 +P&P)