Shape Optimization for Performance Improvement of Ship's U-type Bellows

J. Ocean Eng. Technol. 2006;20(6):123-129.

Kim, Hyoung-Jun;Kim, Hyun-Su;Kim, Jong-Pil;Park, Jun-Hong;Kim, Myoung-Jin;

Graduate School of Mechanical Engineering, DAU;Department of Mechanical Engineering, DAU;Graduate School of Mechanical Engineering, DAU;CANSMC, DAU;Hae Jo Industrial. Co. Ltd.;

선박용 U형 벨로우즈의 성능 향상을 위한 형상 최적화

김형준;김현수;김종필;박준홍;윤명진;

동아대학교 기계공학과 대학원;동아대학교 기계공학부;동아대학교 기계공학과 대학원;동아대학교 신소형재가공청정공정개발연구센터;해조산업(주);

Keywords: Design of experiment, Shape optimization, ANOVA (Analysis of variance), Bellows, Design factor, Level, Fatigue life

핵심용어: 실험계획법, 형상 최적화, 분산 분석, 벨로우즈, 설계인자, 수준, 피로수명

Abstract

The mechanical properties of bellows, such as the extensibility and the strength can be changed depending on the shape. For the shipbuilding material, it is desirable that the fatigue life is long due to the elastic property and the reduction of thermal stress in piping system. Nowadays, the domestic production and design of bellows are based on the E.J.M.A. Code. Therefore, the design standard is in need because of much errors and lack of detailed analysis. In this study, it is attempted to find out the optimal shape of U-type bellows using the finite element analysis. The design factors, mountain height, length, thickness, and the number of convolutions are considered and the proper values are chosen for the simulation. The results shaw that as the number of convolutions reduces, the volume decreases while the stress increases. However, as the number of convolutions increases, the volume increases above the standard volume and the stress obviously increases. In addition, the effect of the thickness of bellows on the stress is very large. Both of the mass and stress are decreasing at a certain lower value region. Also, we investigated shape optimization with considering maximum stress distribution tendency.