Experimental and analytical studies of high strength steel channel sections in bending ​and bolted t-stubs in tension​​

Abstract

The first topic presented in this report is an experimental investigation of flexural behaviour of high strength steel channel sections. A total of twelve beams were tested under four-point-bending about their minor axes with auxiliary tensile coupon tests conducted. The experimental results were then compared with the design provisions of EN1993-1-12, which is found to give rather conservative and scattered predictions of cross-sectional bending resistance as it neglects the beneficial element interaction and the strain hardening effect. Thus, a strain-based approach named the continuous strength method (CSM) was implemented. It categorises a cross-section and its moment resistance with its deformation capacity and accounts for strain hardening with a bi-linear material model. CSM has been extensively researched and developed for stainless steel members and structures, yet this report is one of the few to examine its application on high strength steel. Through comparison with the test results and EN1993-1-12 design approach, CSM is observed to yield more accurate and consistent predictions, therefore, a higher design efficiency. The second topic is an analytical study on the ultimate resistance and deformation capacity of high strength steel bolted t-stubs. Existing test results on eleven high strength steel t-stubs were briefly reviewed and compared with the predictions from an analytical model derived initially for mild steel. A satisfactory agreement was observed and reported in detail.