Inward-contracted folding element for thin-walled triangular tubes

摘要: Abstract Extensional and in-extensional folding elements are two conventional plastic collapse mechanisms for thin-walled tubes to predict their anti-crushing behaviors. In the compression experiments of triangular tubes, a new element, named as inward-contracted was observed. Accompanying with this mechanism, double zigzags half-shortened wavelength were observed in corresponding deformation curve compared curves collapsing at modes. This element always follows behind extensional form hybrid element. A model proposed, through which mean crushing force (MCF) predictable.