| The application of sophisticated geometric structures within future host materials for increasing energy absorption and compression strength, while being fabricated from crack-healing materials, is of high interest for many functions. Raw feedstock extrusion and three-dimensional printing (3DP) technology were used to develop precise honeycomb structures through intricate deposition of polycaprolactone (PCL) filament. For standardization purposes during 3D model slicing and print quality consistency, constant wall thickness was used for honeycomb structure fabrication, manipulating only the cellular width to obtain variation of cell size to wall thickness ratios.;The honeycomb structures' compression behaviors were studied through use of in-plane quasi-static uniaxial compression testing. Multiple cycles of compression loading were applied to the specimens in both transverse and ribbon directions at temperatures of 5 °C, room temperature (i.e. 22 °C), and 40 °C at a speed of 1.27 mm/min (0.05 in/min) per ASTM D6641. The energy absorption efficiencies of the honeycomb structure were calculated based on the compression strengths and behaviors displayed, which were then used to obtain the stepping upward stress theoretically. Using the specified stepping upward stresses, the energy absorption capabilities were found in both the transverse and ribbon directions at different temperatures per unit volume. The ability for "shape recovery" of the structures after each loading cycle was also calculated.;Outcomes from this research displayed exceptional recovery of PCL honeycomb structures after repeated compression loading cycles. Samples with relative density of 0.20 absorbed energies of up to 0.99 J/cm3. Upon removing compression loads, samples were capable of shape recovery up to 80% after the first deformation and up to 72% after the fifth deformation. When PCL honeycomb structures are used to reinforce host materials, they increase energy absorption capabilities while being capable of crack-healing functions with remarkable compressive strength. These properties make PCL advantageous for many industries. |
