Compressive behavior and energy absorption of SLM-fabricated diamond-TPMS tube reinforced with bionic spider-web ribs

Aluminum alloy thin-walled tubes are widely used in lightweight energy-absorbing structures owing to their high specific strength and crashworthiness. However, Diamond-type triply periodic minimal surface (TPMS) tubes may exhibit unstable penetrating 45° shear band deformation under axial compression. To mitigate this instability, a bionic spider-web rib-reinforced Diamond-TPMS tube (D-BCT) is proposed based on spatial–structural partitioning, dividing the annular region into an inner rib-reinforced region and an outer Diamond-TPMS region. Three specimens of each structure were fabricated from AlSi10Mg alloy by selective laser melting and tested under quasi-static axial compression. Within a common 0–15 mm evaluation displacement, the D-BCT achieved a mean specific energy absorption (SEA) of 38.74 J/g, approximately 9.9% higher than that of the conventional Diamond-TPMS tube (D-CT), while reducing the mean peak crushing force by approximately 30.7% and increasing the mean crushing force efficiency (CFE) from 64.66% to 74.92%. Compared with D-CT, D-BCT exhibited progressive crushing and buckling rather than a penetrating shear band, together with a more stable plateau response. These results suggest that spatial–structural partitioning is a promising approach for improving the quasi-static crushing stability of Diamond-TPMS tubes.