F. Soetens

Structural adhesive bonded joints in engineering – drafting design rules

This paper introduces methods to draw up design rules to calculate the resistance of adhesive bonded joints for structural

Aluminium Structures in Building and Civil Engineering Applications

Structural applications of aluminium are considered in this paper. Although the discussion is mainly devoted to Europe, the paper also refers, where possible, to developments in other parts of the world. The problems faced by a designer in creating an optimum design are described, followed by a brief review of the research carried out in the past four decades on the structural behaviour of aluminium and a preview of topics still to be investigated. A historical overview of standards is then given, starting from the ECCS Recommendations up to the recently published Eurocode 9. Finally, a number of structural applications are dealt with, as well as some future directions and concluding remarks.

Fatigue of aluminium bridge decks

Traffic bridges are subjected to variable loads and should therefore be checked on fatigue. Especially low weight materials, such as aluminium, are sensitive to fatigue, because the variable load is a substantial part of the total load. This paper discusses the fatigue behaviour of an extruded aluminium deck. To determine the fatigue lifetime, the well-known procedure based on S-N curves was applied. In tests, the S-N curve was determined of a welded detail applied often in aluminium bridge decks.In order to check the procedure based on S-N curves, fatigue tests were carried out on a specimen with geometry and loading conditions that are realistic for bridge decks.

Design of Connections

Although a lot of research on aluminium alloys has been carried out in the past, relatively little attention has been given to their structural behaviour. Therefore, in the past most design rules for aluminium alloys were based on design rules for steel.

Numerical simulation of fatigue crack growth rate and crack retardation due to an overload using a cohesive zone model

In this work, a numerical method is pursued based on a cohesive zone model (CZM). The method is aimed at simulating fatigue crack growth as well as crack growth retardation due to an overload. In this cohesive zone model, the degradation of the material strength is represented by a variation of the cohesive traction with respect to separation of the cohesive surfaces. Simulation of crack propagation under cyclic loads is implemented by introducing a damage mechanism into the cohesive zone. Crack propagation is represented in the process zone (cohesive zone in front of crack-tip) by deterioration of the cohesive strength due to damage development in the cohesive element. Damage accumulation during loading is based on the displacements in the cohesive zone. A finite element model of a compact tension (CT) specimen subjected to a constant amplitude loading with an overload is developed. The cohesive elements are placed in front of the crack-tip along a pre-defined crack path. The simulation is performed in the finite element code Abaqus. The cohesive elements behavior is described using the user element subroutine UEL. The new damage evolution function used in this work provides a good agreement between simulation results and experimental data.

Structural Design of Aluminium Bridge Decks for Existing Traffic Bridges

This paper describes how many traffic bridges are constructed using a hardwood deck that is supported by a steel structure. These hardwood decks have to be replaced regularly. This paper discusses using extruded aluminum bridge decks as an alternative for timber decks for the renovation of these bridges. The paper pays special attention to fatigue design and connections between steel and aluminum structures.

Design of an Aluminium Bicycle Path Integrated in a Steel Bridge

This paper describes the design of the aluminium structure of a bicycle path which is mounted on an existing steel brige. The benefits of aluminium, being low self weight, freedom in design obtained by extrusion and good corrosion resistance were maximal utilized. One of the main drawbacks of aluminium, being the low modulus of elasticity, caused that special attention was paid to stability and vibration of the decks. The paper shows how structural aluminium and steel can be combined in one structure

Design of welded connections in aluminium structures

In the past decades a number of studies have been carried out to enlarge the knowledge on the structural behaviour of aluminium alloys.This research effort has resulted in up-dated design rules in national codes, but most importantly a draft European code “Eurocode 9: Design of Aluminium Structures” has been edited in 1998 (the final version will be edited in 2006), which contains the most up-to-date design rules for aluminium structures [1].The paper will deal with the design of connections in aluminium structural applications and in particular with the design of welded connections. The motive to select this subject is twofold.At first, welding is the most important joining method for structural applications in aluminium. And secondly, welding aluminium differs from welding steel, while bolted connections in steel and aluminium are quite similar.So attention will be given to specific aspects of welded connections which differ from steel. At last, the paper will survey the most important design rules of welded connections in aluminium structures according to the final version of Eurocode 9.

Experimental work and FEM-calculations on the interaction of local buckling modes in aluminium sections

The extrusion manufacturing process of aluminium allows protiles with a large variety of cross-sections. If these are thin-walled. cross-sectional instability miszht occur, which is caused by interaction of local buckling modes of connecting plate elements. To investigate this phenomenon. an extensive set of experiments is performed on uniformly compressed aluminium RHS-sections at Eindhoven University of Technology. In-plane and out-of-plane plate detormations are visualised using a so-called ESPI-laser system. The tests are used to alidate a finite element model. which results are presented as welt. In a subsequent research this model will he used to analyse the failure modes of more complex sections.

Numerical/Experimental Research on Welded Joints in Aluminium Truss Girders

Welded joints in a 30 meter span aluminium truss girder were investigated numerically and experimentally. Since aluminium design rules for welded K-and N-joints in CHS truss girders were lacking the joints were checked using steel design rules. Calculations showed that the N-joints were governing for chord and brace sizes. Further numerical analysis on the N-joints using ANSYS 11.0 was carried out. Full scale experimental research was successfully carried out for validation of the numerical calculations. It is concluded that steel design rules predict the failure behavior and failure mode of the considered aluminium N-joints well. However, steel design rules overestimate the failure load by 8% for the truss configurations investigated.