This paper presents a method for the assesment of vibration fatigues in engine exhaust system. Analysis technologies by virtual model can reduce the number of physical tests and development cycles. The prediction processes are based on the construction of FE model for the exhaust system, normal mode analysis, and frequency response analysis. The analysis results(1st mode: 152Hz) of eigen frequencies are compared with the modal test results(1st mode: 151Hz). And frequency response analysis for accelerations and stresses at critical locations were also presented. The analysis method could be applied to assess the vibration fatigue for the engine exhaust manifold. As a result, maximum stress occurred at the end of diffuser and its frequency shows around 1st natural frequency of exhaust system. It shows a good agreement between numerical and experimental results.

Abstract
 1. 서론
 2. 본론
  2.1 해석 과정
  2.2 유한요소 모델
 3. 해석 결과
  3.1 파손현상
  3.2 고유진동해석
  3.3 주파수응답해석
 4. 결론
 참고문헌

• 이경로(신성대학교 자동차계열 교수) | K. R. LEE
• 최복록(강릉원주대학교 기계자동차공학부 교수) | B. L. CHOI Corresponding Author