Evaluation of repairing techniques for damaged natural fiber reinforced composites

Research output: ThesisMaster's Thesis

Abstract

Fiber reinforced polymer composites employed in industries such as aerospace and automotive, are susceptible to deteriorate over time as a result of impact and moisture absorption. With the widespread use of composite materials, the demand for technologies capable of repairing damaged components rather than replace them has increased in past decade. Additionally, the use of bio-based constituents in composites materials shows an upward trend in the industry. This work will focus on repairing natural fiber reinforced composites, specifically Flax-based composites. For this purpose, two formulations of resin are utilized, a bio-based epoxy resin and a Vitrimer resin. Each resin system undergoes a distinct repair technique: injection repair for epoxy-based composites and forming for Vitrimer-based ones. The specimens were produced using vacuum assisted resin infusion. The specimens were cut from these plates. A drop weight impact machine was used to damage the specimens in controlled, low-velocity impact test. The repair process for damaged epoxy-based specimens involves resin injection aided by vacuum. The damaged Vitrimer-based specimens were formed over a four-hour period within a heating press operating at 160°C. The efficiency of the repair methods was assessed using active thermography and compression after impact test. Both evaluation techniques demonstrated that the injection repair technique produced favorable results, demonstrating the effectiveness of the repair method for the chosen system. Although the thermographic outcome from the forming technique were positive, the compression properties highlights is ineffectiveness for the chosen natural fiber and Vitrimeric system.

Details

Translated title of the contributionEntwicklung eines Reparaturprozesses für beschädigte naturfaserverstärkte Verbundwerkstoffe
Original languageEnglish
QualificationMSc
Awarding Institution
Supervisors/Advisors
Award date20 Oct 2023
DOIs
Publication statusPublished - 2023