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. "
Degradation Mechanism of the Golf Balls in High Temperature and High Humidity Environment and Development of Its Evaluation Technique
In order to detect degradation in golf balls, degradation mechanism in golf ball was investigated and ultrasonic testing technique was applied to evaluate degradation in golf balls. Degradation mechanism of golf ball was first studied during water, high temperature and high temperature with high humidity environment. Degradation was evaluated by using restitution test, indentation test and compression test. Coefficient of restitution and hardness were rapidly changed in high temperature with high humidity environment, respectively. Hardness of the cover increased with increasing test time and hardness of core decreased with increasing test time. There was good relationship between change in hardness of cover and compression stiffness that detected in compression test in the balls used in this study. Ultrasonic testing was next applied. Change in arrival time of symmetrical mode wave that was propagated in the cover was corresponded to the change of hardness in the cover. Thus, degradation of the golf ball was roughly estimated by using ultrasonic technique in this case. In order to detect degradation in golf balls, degradation mechanism in golf ball was investigated and ultrasonic testing technique was applied to evaluate degradation in golf balls. Degradation mechanism of golf ball was first studied during water, high temperature and high temperature with high humidity environment. Degradation was evaluated by using restitution test, indentation test and compression test. Coefficient of restitution and hardness were rapidly changed in high temperature with high humidity environment, respectively. Hardness of the cover increased with increasing test time and hardness of core decreased with increasing test time. There was good relationship between change in hardness of cover and compression stiffness that detected in compression test in the balls used in this study. Ultrasonic testing was next applied. Change in arrival time of symmetrical mode wave that was propagated in the cover was corresponded to the change of hardness in the cover. Thus, degradation of the golf ball was roughly estimated by using ultrasonic technique in this case.
Trends in kiln drives
The heart of the cement plant is the rotary kiln, and continuous quality production of cement clinker depends on the continuous accurate performance of the rotary kiln drive.