Experimental and Numerical Analysis of the Fastening Bolt Using the Plastic Buckling Deformation of a Pipe(<Special Issue>Design or Process Technology for Mechanical and Adhesive Joint Structures)

One-sided fastening bolt using the plastic buckling of a pipe which is annealed along the length is studied in this paper. In fastening process the pipe is buckled to form a bulb in the annealed area under an axial compressive load from the bolt and the formed bulb can be used as the backside head of the bolt. Since the pipe geometry is the single design variable for the strength of fastening system, estimations of effects of geometrical parameters of pipe on buckling process and fastening process are very important. The whole fastening process is studied by the nonlinear finite element analysis consistently. Effects of the pipe length on the formed bulb and load in buckling process and the deformation behavior and load is fastening process are investigated for two different diameter pipes. Buckling and fastening experiments are carried out to verify the simulation method proposed. Numerical results are compared with experimental results for load and deformation modes in buckling and fastening process, showing fairly good coincidence. Three different types of deformation modes in fastening process are found in the analyses and experiments. Under the mode which has a large area contact to the bolt head, the fastening strength can be introduced rapidly and the high fastening strength is expected.