3D printing and testing of composite isogrid structures

Abstract

The present work aims at studying the effect of geometric parameters of isogrid structures on their buckling behavior. To this purpose, isogrid structures in polyamide reinforced with short carbon fibers, with different rib widths, rib thicknesses, and cell heights, were additively manufactured using the fused deposition modeling technology; then, they were subjected to compression test until the occurrence of buckling. It was observed that isogrid structures can undergo to different failure modes, local and global buckling, depending on the values of geometrical parameters. Furthermore, the geometrical parameters that lead to the highest strength are different to those providing the highest specific strength. However, the specific strength of the 3D printed composite material is higher than those of 1XXX and 3XXX aluminum alloys. Rib thickness was characterized by the highest effect on both strength and specific strength while the cell height results in the lowest contribution. Finally, optical and scanning electron microscopies were carried out in order to analyze the fractured ribs and to obtain high magnification three-dimensional topography of fractured surfaces after buckling. The effect of moisture content on polyamide reinforced composites and the comparison between 3D printed and traditionally produced isogrid structures will be investigated in future researches.

Compression behavior of 3D printed isogrid cylindrical shell structures using experimental and finite element modeling

“…Figure 15 depicts the shell thickness and rib width on the peak load of the shell during quasi-static compression loading. For width of ribs and shell thickness as 5 mm the compressive loading bearing capacity is maximum for the isogrid shells, which is similar to the pattern observed by Forcellese [35] in their study on the compression behavior of isogrid plates.…”

“…Many of the ongoing research has focused on the manufacturing and mechanical characterization [30] of continuous fiber reinforced thermoplastic filament materials, which efficiently overcome the disadvantage of low mechanical characteristics of traditional thermoplastics. [31][32][33] As on date, Li et al [34] and Forcellese et al [35] are the two researchers proposed the relevant work in the literature on 3D printed isogrid structures, in which the former explored the 3D printed isogrid panels using buckling tests and FEM analysis to develop a multifailure theory and the later studied the effect of geometric parameters of isogrid panels on their buckling behavior. As a result of past research on isogrid structures, the buckling behavior of isogrid panels has received the greatest attention, but the isogrid lattice cylindrical shells have been overlooked.…”

Influence of Geometric Parameters on Buckling Behavior of 3D Printed Anisogrid Structures

“…High times and high-costs production for anisogrid structures manufactured by fiber-reinforced composite material made FFF technology as an excellent method for the production of such structures. However, this topic is not sufficiently investigated in the literature, since only few previous articles by the authors is available [16]. This work shows that the buckling behaviour of 3D printed composite isogrid structures is strongly related to the moisture absorption of the polyamide matrix; in addition, the increase in the height of the cell leads to a decrease in both the maximum load and the specific maximum load, while the increase in the width of the ribs leads to an increase in both the peak load and the specific maximum load.…”

Thermoplastic Mandrel for Manufacturing Composite Components with Complex Structure

“…In order to solve the problem of difficult demolding, experts and scholars at home and abroad carried out relevant research. Forcellese et al studied the 3D printing technology of composite materials, formed the composite grid structure with complex shape, and tested its strength [13]. Hao et al established a fused deposition modeling (FDM) 3D printing platform [14].…”