수정 Plantema식을 이용한 원형튜브의 국부좌굴하중 예측

Abstract

A crushing tube is the most widely used energy absorber in the crushing system. For the reliable design of the crushing tube, the accurate local buckling load of the tube should be predicted since the crushing tube uses the local buckling of a tube wall for crushing energy absorption. On the other hand, the local buckling should be prevented in some device which needs the stability. Therefore, the prediction of the accurate local buckling is important to use or prevent the local buckling. The Plantema equation is the most widely used equation for prediction of the inelastic local buckling load of a thin-walled cylindrical tube. In accordance with the finite analysis result, however, the local buckling load from the Plantema equation cannot predict the accurate local buckling load since it is from the perfectly plastic assumption. In this paper, a prediction method of the local buckling load is suggested by modifying the Plantema equation. By using the modified Plantema equation, the local buckling load of the thin-walled cylindrical tube can be predicted using the material properties of the tube material without finite element analysis. The results from modified Plantema equation show good agreement with the numerical and experimental results.