Square tubes with graded wall thickness under oblique crushing

Thin-walled square tubes with graded wall thickness were previously found to be more efficient in terms of energy absorption than square tubes with uniform thickness subjected to axial compression. In this paper, the mechanical performance of square tubes with in-plane graded wall thickness under oblique compression has been investigated for the first time. Three different types of square tube configurations: four walls with uniform wall thickness, single-surface graded wall thickness (SSG) and double-surface graded wall thickness (DSG) were experimentally compressed at loading angles of 0 degrees, 10 degrees and 15 degrees, respectively. Finite element models were subsequently developed to study the effects of wall thickness, graded thickness configuration and loading angle on deformation modes, force-displacement curves and energy absorption. The results show that both SSG and DSG tubes display better specific energy absorption than tubes with uniform thickness and very similar mass under oblique compression. With the increase of the loading angle, the specific energy absorption of all tubes studied decreases except SSG0814 tube. DSG tubes present similar specific energy absorption as that of the corresponding SSG tubes under axial and oblique loadings.

Automated summary

The mechanical performance of square tubes with in-plane graded wall thickness under oblique compression has been investigated for the first time in this study. Experimental results show that both single-surface graded wall thickness (SSG) and double-surface graded wall thickness (DSG) tubes display better specific energy absorption than tubes with uniform thickness under oblique compression.