Papers by Author: Won Kyung Kim

Abstract: In this paper, we describe a carbody structural analysis and the result of its stress test. The purpose of this study is to evaluate the safety and functionality of the body structure operating under maximum load. The body structure was made of aluminum alloy and consisted of the side frame, under frame, roof frame, and end frame. Of these components, the side frame and under frame were the most important components in consideration of the vehicle and passenger loads. Both the structural analysis and stress test were performed under the condition that was based on the "Performance Test Standard for Electrical Multiple Units." The test results showed that the body structure is safe and stable under the condition of the designed load.

Abstract: This paper describes the results of structural analysis and loading test of a bogie frame. The purpose of the analysis and test is to evaluate the safety and functionality of the bogie frame under maximum load. The bogie system consist of the bogie frame, suspensions, wheel-sets, a brake system and a transmission system. Of these components, the bogie frame is the major component subjected to the vehicle and passenger loads. The evaluation method used the JIS E 4207 specifications throughout the FEM analysis and static load test. The test results have shown the bogie frame to be safe and stable under design load conditions.

Abstract: This paper describes the results of structural analysis and loading test of a bogie frame. The purpose of the analysis and test is to evaluate the safety and functionality of the bogie frame under maximum load. The bogie system consist of the bogie frame, suspensions, wheel-sets, a brake system and a transmission system. Of these components, the bogie frame is the major component subjected to the vehicle and passenger loads. The evaluation method used the JIS E 4207 specifications throughout the FEM analysis and static load test. The test results have shown the bogie frame to be safe and stable under design load conditions.

Abstract: Several nondestructive evaluation (NDE) techniques, including ultrasonic C-scan, X-ray computed tomography (CT), and infrared (IR) thermography, were employed on ceramic matrix composites (CMCs) to illustrate defect information that might effect mechanical behavior and to analyze structural performance of CMCs. Prior to tensile testing, through C-scan and CT analyses results, the qualitative relationship between the relative ultrasonic transmitted amplitude and porosity based on CT was exhibited. An IR camera was used for in-situ monitoring of progressive damages and to determine temperature changes during tensile testing. Moreover, scanning-electron microscopy characterization was used to perform microstructural failure analyses. This paper describes the use of nondestructive evaluation (NDE) techniques to facilitate the understanding of tension behavior of CMCs.

Abstract: Nondestructive evaluation (NDE) techniques were used for the tensile damage characterization in ceramic matrix composites (CMCs). Ultrasonic testing (UT) and infrared (IR) thermography were employed to assess defects and/or damage evolution before and during mechanical testing. Prior to tensile testing, a UT C-scan and a xenon flash method were performed to obtain initial defect information in light of UT C-scans and thermal diffusivity maps, respectively. An IR camera was used for in-situ monitoring of progressive damages. The IR camera measured temperature changes during tensile testing. This paper has presented the feasibility of using NDE techniques to interpret structural performance of CMCs.