“…By changing the shape of the thin-walled tube structure, the designs of grooves (groove, half groove), holes (round hole, square hole, etc. ), stiffeners, functionally graded tubes, multi cell tubes, nanocrystallized tubes [7] and the pre-creased tubes were carried out; Daneshi et al [8] introduced the groove into the design of the circular thin-walled tubes, and controlled the displacementload curve by changing the width of the grooves and the spacing between the grooves, so as to improve the energy absorbed by the tubes. Li et al [9] studied the energy absorption capacity of functionally graded composite tube under oblique loading and indicated that the energy absorption efficiency is the highest when the power-law index is 2.…”