| dc.description.abstract | In this thesis, a type of pin joint, namely Bondura Expanding Pin System (EPS) is subject of study which has ability to create a rigid and reliable connection. This joint system is specially designed for heavy duty machines where excessive loading to the pin can cause damage to the joint components and create slack in the connection that often leads to malfunctioning in the machine.
This research concentrates on two concepts; stress analysis of the EPS and optimization of it. To achieve these goals, combination of analytical, experimental and Finite Element Analysis (FEA) are carried out. The available formulas for different parts of EPS are investigated. For assessing validity of formulas available in literature for interaction between conical pin-sleeve, a FEA is performed using Abaqus/CAE software. Bondura sleevewhich is an expanding (split) sleeve has four cuts that one of them is a complete cut (cut-through). The comparison of the results show that existing formulas can be used for initial prediction of stresses and pressure in EPS with good precision.
The experimental job is conducted in order to find out stress level and distribution in the equipment support. For this purpose, a thick cylinder was manufactured as test boss and in several locations along its outer surface, induced strains were measured while EPS joint was subjected to fastening torque of screws. Comparison of results of the conducted FEA and experimental values for stress state in the test boss are in good agreement. The effect of friction and expansion of sleeve on stress state of test boss is analysed comprehensively in the experimental part of this study. Moreover, a FEA is implemented for parametric study of friction. A relationship between maximum von Mises in the test boss and friction coefficient is extracted regarding the fastening torque of 200 Nm.
After carrying out stress analysis on EPS and verification of the FE model, the optimization process was implemented in order to find a shape which creates a lower stress state in the joint components while preserving enough pressure or radial stress to ensure suitable clamping force in the joint. The optimization result provided a profile for tapered section of pin-sleeve mating surface. The optimised profile needed some modifications to make it applicable in joint assembly. FE results show that for the new optimised shape, applying lower amount of fastening torque to EPS can provide the same radial pressure and clamping force in the test boss.
Finally, a FE parametric study was carried out on angle of taper of pin-sleeve mating section to quantify the best angle. The obtained results show that the current angle of taper of Bondura EPS which is 12° is the most suitable angle since it creates considerable amount of radial stress and consequently clamping force in the equipment support. | |
