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| dc.contributor.author | AMARE, DEMELIE ZEGEYE | |
| dc.date.accessioned | 2024-12-16T12:07:45Z | |
| dc.date.available | 2024-12-16T12:07:45Z | |
| dc.date.issued | 2024-03 | |
| dc.identifier.uri | http://ir.bdu.edu.et/handle/123456789/16384 | |
| dc.description.abstract | Manufacturing high-performance fiber reinforced plastics (FRP) products within short manufacturing cycles is a significant challenge in the industry. This study investigated the application of resin spray-compaction method for long fiber reinforced plastics (LFRP) manufacturing, expecting improved productivity and product quality at low cost. Computational fluid dynamics (CFD) modelling was applied to study the spray, deposition, and compaction phases of the process. The composite components used for the study comprised unsaturated polyester resin and glass fiber. The validation of CFD results for each phase of the process was conducted using techniques of Phase Doppler Anemometry (PDA), camera imaging, press works, and other experimental works. The void and fiber volume fraction (FVF) of laminates manufactured by the process were also inspected using x-ray computed tomography (CT) and image analysis techniques. The findings from the spray deposition study indicated a concentration of smaller resin droplets at the center of the spray plume, while larger droplets were more abundant towards the periphery. When examining the velocity distribution in reverse, it was observed that the speed was higher at the center and lower at the periphery. The distribution of film thickness on the deposition surface was found to be variable, exhibiting thicker and wavy layers around the center, while experiencing a sharp decline towards the periphery. The compaction results revealed significant variations in flow speed of resin between the radial and thickness directions of the preform. The flow behaviour was notably affected by the porosity and permeability of the preform. It was observed that a lower compaction speed had a significant impact on reducing the presence of voids within the produced laminates. At a compaction speed of 1mm/min, the void fraction decreased to as low as 1.5%. On the other hand, the compaction pressure above the compaction speed exhibited a notable influence in determining FVF of the laminate, offering the potential to achieve FVF up to 72%. Based on the study findings, it can be concluded that the resin spray and compaction method can be effectively applied in LFRP manufacturing, and the CFD models developed in this study can be implemented in effectively predicting the process characteristics. The method was proved of having shorter manufacturing time, and reduced product defects. Key words: spray modelling; deposition; porous flow; compaction; fiber; fiber volume fraction; resins; voids. | en_US |
| dc.language.iso | en_US | en_US |
| dc.subject | Mechanical and Industrial Engineering | en_US |
| dc.title | RESIN SPRAY-COMPACTION METHOD FOR LONG FIBER REINFORCED PLASTICS MANUFACTURING: COMPUTATIONAL FLUID DYNAMICS MODELING AND EXPERIMENTAL VALIDATIONS | en_US |
| dc.type | Thesis | en_US |
