Crashworthiness Performance and Multicriteria Decision‐Making of Lightweight Origami‐Inspired 3D‐Printed PLA+ Tubes

Although origami patterns can tailor the collapse of thin‐walled energy absorbers, experimental evidence on additively manufactured polymer origami absorbers and their internal geometry is limited. Origami‐inspired crash boxes printed from toughened polylactic acid (PLA+) by fused filament fabrication are tested under quasi‐static axial compression. Nine configurations combining three groove heights (6, 8, and 10 mm) with three internal geometries (Type1: plain, Type2: same‐phase, Type3: opposite‐phase folding) are evaluated in triplicate, assessed by analysis of variance, and ranked by gray relational analysis (GRA) of the initial peak crushing force (IPCF), crushing force efficiency (CFE), and specific energy absorption (SEA). At the 6‐mm groove height, the internally folded designs (Type2–6, Type3–6) absorb about three times as much energy as at larger groove heights (SEA up to 22.46 J/g). Structure type dominates IPCF (85.1% contribution), whereas groove height governs SEA (76.5%). GRA ranks Type3–6 and Type2–6 highest (grades 0.857 and 0.837); this statistically indistinguishable pair leads under six weighting schemes, 11 decision‐making methods, and 83% of random weight vectors. This ranking is application‐specific: their CFE values above unity reflect a rising force rather than an ideal plateau, whereas the Type1 series shows smoother plateaus with about half the pair's maximum force.