Axial crush can provide controlled and reliable energy absorption for components requiring structural crashworthiness. An experimental investigation using thin-walled, commercial 304 stainless steel box components examined the effect of alloycomposition and microstructure on quasi-static (room temperature) axial crush response. The experimental program consisted of two phases. The objective of the first phase was to develop experimental methods that would generate reproducible axial crush response for a given material. End constraints (removable, grooved caps) and collapse initiators (shallow groove patterns on specimen sidewalls) were used to ensure a specific crush mode and collapse location. A progressive axial crush study was performed in which nine specimens were compressed to record a deformation sequence during a fold formation cycle. Good agreement was obtained for crush characteristic values. The percent difference (average value basis) was less than 3percent for maximum loads, 6percent for minimum loads, and 3percent for energy absorption. In the second phase, the same experimental methodology was used to investigate the effect of alloy composition and microstructre. A higher concentration of carbon and smaller grains resulted in an 18percent increase in energy absorption in a secondary fold cycle. Overall, results showed that if an axial crush component's structural engienering response is controlled, material behavior can be isolated and then, alloy composition and microstructure can be modified to enhance energy absorption performance.
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