Investigation on Steam-based System for Creepforming Dyneema Hemisphere Preform

Investigation on Steam-based System for Creepforming Dyneema Hemisphere Preform

Simbolon, M.R.

Marissen, R. (mentor)
Bergsma, O.K. (mentor)

Aerospace Engineering

Aerospace Structure and Materials

Structural Integrity and Composites

2015-08-27

Previous study in Structural Integrity and Composite group showed that creepforming Dyneema fiber into hemispherical helmet preform is indeed possible. However, the set-up in conventional set-up was complex and a long time was required to generate uniform temperature across the material. This thesis will investigate the possibility of using steam system as heating and pressurizing agent to creep-form the material. Steam is considered as potential agent due to its characteristic to be a good heating agent. The first part of this thesis will cover the analysis of manufacturing process from previous works in order to find their strengths and weaknesses. Using this information a production system that ideally combines the advantages of previous processes will be selected. After manufacturing the molds, the investigation of proposed process' boundary condition can be started. The experiments conducted in this thesis revealed that the available pressure from steam was not enough to creepform Dyneema fiber. The second part of the thesis is directly related with the selection of gas-based system as the main equipment. Since the available pressure is a lot less than the manufacturer's recommended cycle, the result of these experiments revealed several interesting findings. This part will cover the experiments conducted to further clarify the findings. Another consequence of the low available pressure is the final thickness of the product is low. It was then proposed to insert several new layers that are not winded around the mold as a potential solution for this thickness problem. However, the interaction between these "draped" layers with the normal creep layers is still unknown. The investigation will cover several experiments to provide better knowledge of the proposed layer combination idea. For further research, it is anticipated that by utilizing compressed water as the working medium, sufficient pressure to successfully creep-form Dyneema\textsuperscript{\textregistered} fiber can be achieved. A possible set-up design of the system is provided in the recommendation section.

Dyneema
Steam
Autoclave
Hemisphere
Creepforming

http://resolver.tudelft.nl/uuid:86c32d9c-2779-44a3-a6e6-743e78426217

2015-08-31

Student theses

master thesis

(c) 2015 Simbolon, M.R.