Effect of 3D printing parameters and grid shape on geogrid’s tensile and stiffness properties using FDM technique

Abstract

Polyester, Polyethylene, and Polypropylene are the materials widely used as geosynthetics. The utilization of such plastic products causes significant environmental issues due to their degradation. Addressing the environmental issues arising from the challenges associated with the direct degradation of conventional plastic geogrid. This study evaluated the tensile performance of additively manufactured different-shaped biodegradable Polylactic acid (PLA) geogrids, printed three-dimensionally using the material fused deposition modelling (FDM) technique. The printed specimens underwent tensile loading at rates ranging from 2 to 20 mm/min until failure. The parameters investigated include the shape of the grid (uniaxial, biaxial, and Inter AX), the filling pattern, filling ratio, filling form, and tensile rate. The findings indicated that the specimens’ failure was brittle and not contingent upon any particular geometrical configuration or alterations. The onset of failure consistently stemmed from the junctions. The InterAX geogrid exhibited the lowest tensile strength and highest strain, while uniaxial and biaxial strengths are dependent on the tensile rate. The tensile strength of Gyroid patterns of all shapes of grid increases with increasing filling ratio. With the increase in filling ratios, the tensile strength of the line pattern first increased and then decreased. The line 0⁰ attained peak strength at 50% filling ratio and Gyroid 0⁰ at 30% filling ratio, with common ultimate strength at 38% (line 0^o & 45^o) and 51% (Gyroid 0^o &45^o). InterAX geogrid shows the lowest stiffness as compared to Uniaxial and Biaxial geogrids.