A system approach for studying the engine dynamic characteristics requires a cranktrain flexible body dynamic model including crankshaft, connecting rod and piston. By using a multi-body dynamics code, LMS Virtual Lab, rigid body dynamic model and flexible multi-body dynamic model were established. From these models, the dynamic loads acting on the crankshaft were calculated. Rigid model for V12 engine cranktrain with components connected by kinematical constraints was transformed into a flexible model by replacing rigid crankshaft and connecting rods with flexible ones. And to secure the credibility of flexible body model, three kinds of flexible models were tried, i.e. a model with a fully flexible crankshaft, model with a partially flexible crankshaft(1/6 of the whole length), and a partial detailed flexible model(with finer meshes). The results from each model were compared, and a partial detailed model with finer meshes was found to give reasonable stress values within relatively short period of computing time.

Abstract
 1. 서론
 2. 크랭크트레인 동력학 모델링
  2.1 크랭크트레인의 강체 모델
  2.2 크랭크트레인의 유연체 모델
  2.3 크랭크샤프트 부분유연체 및 상세유연체 모델
  2.4 크랭크트레인 입력데이터
  2.5 유연체 동력학 해석절차
 3. 크랭크트레인 동력학 해석
  3.1 강체 동력학 해석
  3.2 유연체 동력학 해석
  3.3 결과 검토 및 크랭크트레인 정적해석
 4. 크랭크샤프트 유연체 모델에 따른 응력 비교
  4.1 부분유연체 모델
  4.2 상세유연체 모델
 5. 결론
 참고문헌

• 안기원(전남도립대학 자동차과) | Kiwon-Ahn
• 성원석(전남대학교 바이오시스템공학과) | Wonsuk-Sung
• 황원걸(전남대학교 기계시스템공학부) | Won-Gul Hwang