Study on after-slip strength of high-strength bolted frictional joints with a filler plate

<p>According to the new Japanese Specifications for Highway Bridges, after-slip behavior should be verified in high-strength bolted frictional joints. Previous studies have investigated slip behavior with a filler plate. They have proposed the reduction factor of slip resistance. On the other hand, the ultimate strength of such a joint with a filler plate is not clear, and its design strength considering after-slip behavior is not also specified. In this study, for high-strength bolted frictional joints with various filler plate thicknesses, tensile tests and FEA were carried out. From obtained results, it was revealed that a filler plate did not resist load in bearing, and the number of bolt shear failure surfaces was decreased to one from two by a filler plate. It is also found that bolt shear strength decreased below the designed value as filler plate thickness is increased. The authors also proposed the simple design model for bolt shear strength in the frictional joints with a filler plate.</p>

Dynamics of Axial Rods With Frictional Joints

Almost every modern engineering structure incorporates some form of mechanical interface, a connection between two otherwise separate mechanical structures. Complex machines and structures such as automobiles, bridges, aircraft, rockets, etc. rely heavily on these interfaces; however, high-fidelity numerical analysis of such connected structures is currently extremely difficult and computationally expensive due to the disparate length and time scales of the interface as compared to those characterizing the overall structure. This paper utilizes recent work in modal analysis of joints using reduced-order models to study the nonlinear effects of these systems while remaining computationally tractable.

Behaviour of Frictional Joints in Steel Arch Yielding Supports

The loading capacity and ability of steel arch supports to accept deformations from the surrounding rock mass is influenced significantly by the function of the connections and in particular, the tightening of the bolts. This contribution deals with computer modelling of the yielding bolt connections for different torques to determine the load-bearing capacity of the connections. Another parameter that affects the loading capacity significantly is the value of the friction coefficient of the contacts between the elements of the joints. The authors investigated both the behaviour and conditions of the individual parts for three values of tightening moment and the relation between the value of screw tightening and load-bearing capacity of the connections for different friction coefficients. ANSYS software and the finite element method were used for the computer modelling. The solution is nonlinear because of the bi-linear material properties of steel and the large deformations. The geometry of the computer model was created from designs of all four parts of the structure. The calculation also defines the weakest part of the joint’s structure based on stress analysis. The load was divided into two loading steps: the pre-tensioning of connecting bolts and the deformation loading corresponding to 50-mm slip of one support. The full Newton-Raphson method was chosen for the solution. The calculations were carried out on a computer at the Supercomputing Centre VSB-Technical University of Ostrava.