STUDY OF THE LIDINOID LATTICE STRUCTURES AS A SUBSTITUTE OF EXPANDED POLYSTYRENE FOAMS (EPS) IN BICYCLIST HELMETS

Lidinoid structure is a triple periodic minimal surface structure (TPMS) that is defined by a mathematic function and cannot be created using traditional manufacturing technologies, so only additive manufacturing technologies are suitable for this purpose In this article, it will be studied different parameters of these structures to obtain the mechanical properties under compression stresses. In particular, four different materials, 4 length cells and four volume fractions were tested ac-cording with the ASTM D1621/00 using a uniaxial testing machine. Specifically, specific stress-strain curve, energy absorption-strain curve, specific energy absorption-strain curve and efficiency-strain curve were calculated. Finally, using 3D scanner, a bicyclist helmet was scanned and 3D model obtained that was the basis to create an innovative helmet using this structure. The main conclusion is that it is possible to substitute traditional materials us-in Lidinoid TPMS in bicyclist helmets and that ABS is the most suitable ma-trial while PLA is the worst one. In addition, additive manufacturing allows to generate helmets with different customizable properties depending on the zone of the head that must be protected. Keywords: lidinoid, foam, EPS, helmet, 3d printing