Optimization of Aluminum Stressed Skin Panels in Offshore Applications

Since the introduction of general European rules for the design of aluminium structures, specific rules for the design of aluminum stressed skin panels are available. These design rules have been used for the optimization of two extrusion products: one for explosions and wind load governing and one for explosions and floor load governing. The optimized extrusions fulfill Class 3 section properties, leading to weight reductions up to 25% of regularly-used shear panel sections. When the design is based on Class 4 section properties, even more weight reduction may be reached. The typical failure mode of the optimized stressed skin panels depends on the applied height of the hat stiffeners. For sections using relatively high hat stiffeners, failure is introduced by yielding of the heat-affected zone. For this type of cross-section, Eurocode 9 design rules and numerical calculations show very good agreement. For sections using relatively low hat stiffeners, failure is introduced by global buckling. For this type of cross-section, Eurocode 9 gives rather conservative results

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

Analytical and experimental research on strength properties of adhesive bonded joints in aluminium structures

The structural use of adhesives in the building industry is growing in interest, due to successful applications in automotive and aerospace industry. However, the potential of adhesive joints is not yet fully utilized in building structures due to a lack of design rules c.q. building regulations. In particular the limited knowledge on the joint strength characteristics as well as the durability of the joint is a restriction for the use in practice. For these reasons analytical and experimental research projects have been carried out at Eindhoven University of Technology (see [1] to [3]). In the present paper only the static strength prediction is worked out in further detail. The project focused on the static failure load prediction of single lap joints using the singularity approach [1]. The lap joint is worked out analytically and numerically. Several elastic models for stress analysis were examined. The Allman-method [4] was worked out further into a singular stress failure criterion. The failure load prediction was verified by experiments on single lap joints with varying overlap length and width