Net section fracture assessment of steel bolted joints with shear lag effect

Abstract

Bolted connections are willingly used in steel structures because of their easiness of fabrication and assembly, but often they are the weakest component in the construction. In case of tensile lap connections, fracture of net cross section usually determines a joint capacity. Additionally, possible eccentricities can affect the distribution of stresses in the cross section and hence its load capacity. Analysis of fracture is a completely different issue compared to well-known and established problems of stability or plastic resistance. Paper relates to steel angle tension members connected by one bolt. It starts from the description of experimental investigations which results were used for hierarchical validation of computational models. Choice between two types of material models (elastic-plastic and Gurson–Tvergaard–Needleman) and building of FE models, representing different degrees of complexity, were described. Paper ends with parametric study taking into account influence of the edge distance from the centre of a fastener hole to the adjacent edge of angle. The paper’s aim is to verify and present the methodology for fracture prediction in steel angle tension members, which can be next extended for bolted joints with larger number of bolts and different geometrical configurations.

Archives of Civil Engineering

“…Hierarchical validation of computational models based on own experimental data was described in [23,24]. Very good accuracy was observed in the failure load predictions.…”

Archives of Civil Engineering

“…Such process and GTN material capabilities are described extensively in [1,[7][8][9]. Used mechanical properties of steel were obtained from tensile tests of standard coupons cut from angle legs made of steel with nominal grade S275 and were equal to fy = 288 MPa, fu = 425 MPa.…”

“…Used mechanical properties of steel were obtained from tensile tests of standard coupons cut from angle legs made of steel with nominal grade S275 and were equal to fy = 288 MPa, fu = 425 MPa. Other parameters which determine the process of material failure in the GTN material model were obtained from available literature [7][8][9] and from calibration process based on own experimental research [1]. The microstructural parameters of the GTN material model employed in simulations are presented in Table 1.…”

“…The first stage of computational model hierarchical validation was described in [1]. It included tests on single plates with drilled holes and tests on angles connected by one bolt to the gusset plates.…”