Characterization of the materials in golf ball construction for use in finite element analysis
The overall aim of the present work is to develop suitable material tests and use the acquired data to produce a fully validated finite element (FE) model that is capable of predicting hysteresis during cyclic loading as well as coefficient of restitution (COR) on high speed impacts. This paper reports the detailed experimental study that has been carried out in order to establish accurate and reliable material properties of a two-piece golf ball. The data has been used with FE package ABAQUS to produce a model of the ball which takes into account material heterogeneity. © 2009 Published by Elsevier Ltd. "
Construction of the Finite-Element Models of Golf Balls and Simulations of Their Collisions
Abstract The purpose of this study is to construct a finite-element (FE) model of golf balls with hyperelasticity and viscoelasticity and to devise a method for construction of FE ball models by investigating the relationship between the material properties and the behaviour of the golf ball during and after impact. As for the material model of the FE ball model, the Mooney-Rivlin model and the three-element viscoelastic model were used. In the FE analysis (FEA), normal and oblique impacts with a rigid body were simulated with these models. The impact load, deformation of the ball, rebound velocity, angle, and spin rate were investigated, and their effects on the behaviour of the ball were analysed by varying the individual material constants which make up the ball models. Then, a method for the construction of an FE ball model was proposed, based on these relationships. Impact experiments were also conducted to obtain the dynamic properties of the golf ball. The solutions of the FEA of the ball model, as constructed by the proposed method, closely matched with the experimental results, and the method was verified by applying the process to other types of golf balls.
Evolution of carbide precipitates in Hastelloy N joints during welding and post weld heat treatment
Abstract The effects of welding and post weld heat treatment (PWHT) on the morphology, composition and lattice parameter of the precipitates in the welding joints of Hastelloy N alloy have been investigated. Joint samples were prepared using a gas tungsten arc welding process with ERNiMo-2 fillers, and then solid-solution treated at 1100 °C for 20 min. After welding, eutectic M6C carbides can be observed in the heat affected zones (HAZ) and weld zones (WZ). These eutectic M6C carbides become spheroidized during the following PWHT. The concentration of Si decreases during the transformation from the primary ones to eutectic ones, and then increases during the spheroidizing process. The total concentration of Si + Cr in M6C carbides remains stable during welding and PWHT. At the same time, the heat leads to the outward diffusion of Mo from the M6C carbides, which results in a decrease of the lattice parameter.