Papers by Keyword: Thread Joint

Abstract: The nonlinear contact mathematic model is constructed for the bolt joint structure on the fixed end of the Gelin column of die casting machinery and the FEM model and optimization mathematic model for the bolt joint structure are realized by software of ANSYS and the APDL language embedded in it. The structural parameters of different type of thread in Gelin column are optimized. After the comparison of equivalent contact stress in the region of the different type of the bolt joint in Gelin column, it is shown that there is more even load-bearing characteristics with the trapezoidal thread than zigzag thread and the maximum of the equivalent contact stress with the trapezoidal thread is decreased about 41% of that in zigzag thread which can effectively improve lifecycle and anti-fatigue performance of the threaded joint in the gelin column.

Abstract: In this paper, we have evaluated the sliding and the loosening behavior of thread joints under transverse loading. Firstly, the critical relative slippage (Scr), less than which the thread joints can keep the fastening, is obtained by the cyclic loading tests. Then, this critical relative slippage is estimated according to the theoretically obtained equation considering the bending deformation of bolt and the geometrical constraint condition. The inclination compliance (kw) of the bolt head used in this equation is evaluated by comparing the experimental result with the corresponding analytical one. In consideration of the nonlinearity of kw with respect to the bolt axial tension, the Scr is well estimated by this equation.

Abstract: Considering the productivity and the maintenance, most of machine and product has many joints (fastening, welding and adhesive joint). Especially, the thread joint has been used the most mainly as a machine element. However, many troubles on strength and reliability of these machine and product are generating in these joints. In this paper, we have evaluated the sliding and the self loosening behavior of thread joints under transverse loading, where the entire response of the thread joint portion exhibits an inelastic one. The finite element analysis using a simple model of thread joints with respect to the relative sliding motion between the parts was performed and compared with the experimental results under quasi-static loading. The critical relative slippage (Scr), less than the value which thread joints can keep the fastening, was obtained by the result of cyclic loading tests. In addition, this critical relative slippage was estimated according to the theoretically obtained equation considering the bolt bending and the geometrical constraint condition. The inclination compliance (kw) of the bolt head used in this equation was evaluated by the comparison of experimental and analytical results from theoretical equation. In consideration of the nonlinearity of kw with respect to the bolt axial tension, the Scr is well estimated by this equation.