7A04-T6 high-strength aluminium alloy SHS and RHS beams under pure bending—Testing, modelling and design recommendations

Abstract

This paper presents both experimental and numerical investigations into the flexural behaviour of 7A04-T6 high-strength aluminium alloy rectangular and square hollow section (RHS/SHS) beams subjected to four-point bending. A total of 15 bending tests were conducted on RHS and SHS beams with non-slender and slender cross-sections. The test set-up, instrumentation, experimental procedure and results, including measured material properties, failure modes, moment capacities of specimens, were fully reported. Based on the developed and validated finite element (FE) models, an extensive parametric study over a wide range of cross-section slenderness and width-to-height ratios was carried out. Following this, moment capacities obtained from the tests and FE analyses were used to assess the accuracy of current codified design methods provided by the European code (EN 1999-1-1:2007), Chinese standard (GB 50429-2007) and American Aluminium Design Manual (ADM 2015). It is shown that the predicted design resistances were generally conservative up to 37%. Towards meeting the need of a more comprehensive design method, the continuous strength method (CSM) was extended to the 7A04-T6 high-strength aluminium alloy SHS and RHS beams under pure bending and proved to be more accurate for predicting the moment capacity. Finally, the reliability of these four design methods were calculated and confirmed to satisfy the corresponding target reliability indices.