자동차 배기 머플러 구조 피로내구성 평가

Abstract

자동차 배기 머플러 구조는 주행 중 진동으로 인한 극심한 피로하중을 받게 되고 구조적으로 취약한 필렛 용접부에서 자주 파손이 발생한다. 따라서 설계개발 과정에서 피로수명에 대한 평가가 요구된다. 본 연구는 머플러 구조의 피로내구성을 평가하기 위하여 주행 시험 데이터로부터 국부변형률 스펙트럼을 산출하고 스트레인-피로수명 시험 데이터를 기초로 잔여강도 저하모델을 사용하여 피로내구성을 평가하였다.

It is one of the important design assessment items to evaluate the fatigue life for the exhaust system of automobile. For this purpose, it is necessary to describe reliable load spectrum expected during the real operation of automobile. A study on the development of operational load spectrum for the exhaust system of automobile and the analysis of welded part were carried out to obtain the local strain spectrum on the spot where the fatigue damages are mostly anticipated. Using these results, fatigue life evaluation was performed on the basis of the strength degradation model with strain-life test data.

It is one of the important design assessment items to evaluate the fatigue life for the exhaust system of automobile. For this purpose, it is necessary to describe reliable load spectrum expected during the real operation of automobile. A study on the development of operational load spectrum for the exhaust system of automobile and the analysis of welded part were carried out to obtain the local strain spectrum on the spot where the fatigue damages are mostly anticipated. Using these results, fatigue life evaluation was performed on the basis of the strength degradation model with strain-life test data.