Multi-variable Effects of Fastening Parameters on Stress Development at Bolt Threads

Factorial analyses of stress concentrations at the bolt thread root based on finite element models are presented in this paper. A full bolted joint including a bolt, a nut, and fastened members were modeled using solid elements. Bolt and bolt threads were meshed in detail in 3-dimensional mode, with their interaction being only the direct load transfer between the bolt and nut. Statistical design of experiments was conducted to identify the factors and two-factor interactions, which may have impact on the stress concentration at the bolt thread root.