Consideration on the eccentricity factor in the progressive crushing of tubes

Abstract

In this paper, the eccentricity factor in the progressive crushing of tubes subjected to axial compression is studied by using finite element method. It is found that the eccentricity factor is dependent on the thickness-to-radius ratio t/R0 : the eccentricity factor for a thick tube is higher than that for a thin tube. The reason why the eccentricity factor is a function of t/R0 and always takes the value of m > 0.5 is related to the fact that the relations between the stress and strain are different in the outside portion and inside portion of the fold produced in the crushing. Based on the consideration of this fact, an approximation equation is proposed to evaluate change of the eccentricity factor with the tube thickness.