Numerical modelling of solid slab push-out tests with stainless steel welded stud shear connectors

Push-out tests on composite steel-concrete beams are a standardised method for assessing the load-slip capacity of shear connectors, such as welded headed studs. Experimental push-out tests can be costly and time-consuming, so finite element (FE) numerical analyses provide an alternative for producing data on shear stud performance via parametric analyses, provided the numerical model has been accurately validated. Stainless steel has recently gained attention for use in composite construction due to its excellent durability, as well as ductility and strain hardening properties. Very few experimental push-out tests have been conducted on stainless steel shear studs in solid slabs, partly due to the high costs of stainless steel materials. Following a review of common push-out modelling approaches in the literature, this paper presents a comprehensive framework for FE modelling of stainless steel push-out tests, including ductile damage for the welded studs, which can be applied to different stud grades, geometries and arrangements. The modelling approach is demonstrated to accurately capture elastic, plastic and post-peak load-slip response, as well as failure mode, from three distinct test programs on stainless steel and carbon steel welded shear studs. A parametric study is carried out to investigate the effects of stud aspect ratio h/d on the capacity and ductility of austenitic EN 1.4301 stainless steel studs, and the results are compared to the recommended h/d limit in Eurocode 4.