Failure analysis of bolted steel plate connections with three-dimensional flexibilities

Steel plates are widely used in construction to connect different structural elements using welding or bolts. The fracture in these plates may lead to catastrophic consequences such as structural collapse. The paper investigates steel plates' deformation capacity and fracture behavior in bolted connections in three-dimensional (3D) flexibility. The peridynamic method is utilized to model the excessive deformation and fracture of steel plates in bolted connections when they are influenced by shear, moment, and torsion. The mesh-free nature of peridynamics enables modeling the extreme deformation and fracture in ductile materials such as steel. We validate the 3D peridynamic model by comparing its fracture and deformation results with experimental measurements and observations in several loading and boundary conditions. The paper highlights the following novelties: (1) a new and highly efficient 3D peridynamic model is proposed to model fractures in steel plates when exposed to combined actions of shear, moment, and torsion simultaneously; (2) the proposed 3D peridynamic model overcomes the difficulties faced by the mesh-based methods in modeling excessive deformation in ductile materials such as steel; (3) the study also reveals a shift in the fracture behavior of steel plates from ductile to brittle when exposed to high values of moment and torsion. This shift in fracture behavior has not been thoroughly addressed, impacting the integrity of steel structures and the warning stage for yielding. Overall, utilizing the 3D peridynamic model as a modeling and simulation tool can help engineers and researchers examine the behavior of steel plates under various loading conditions, thus allowing for optimization of the design of steel plates used widely in steel construction.