Numerical study on compression properties of semi-reentrant filled tubular structures

In this study, a semi-reentrant structure (SR) filled with different tubular structures, includ-ing tube, triangular and rectangle structures were designed. The tubular structures were perfectly assembled into semi-reentrant cells to avoid swaying in the semi-reentrant cell. The geometric relations and relative density for these structures were established. For the out-of-plane and in-plane compressions, SR filled tubular structures exhibited different de-formation patterns compared to those of SR or pure fillers. A constraint effect was found between the filler tubular and container SR. With fillers contained inside the SR structures, the plateau stresses for three conditions were all promoted compared to those of SR. The best out-of-plane compression resistance occurred in the SR filled rectangle which might be caused by larger interaction areas between the SR and rectangular structures. The (specific) energy absorption of the SR filled tube compressed out-of-plane was the largest. The peak and plateau stress of the SR filled triangle was the largest compared to other structures when compressed in plane due to stability of the triangle. It was found that the plateau stress, energy absorption and specific energy absorption of SR filled triangle was the largest, while that of SR filled rectangle was the lowest.