Concurrent conceptual design of hybrid natural/glass fiber reinforced thermoplastic composites for automotive parking brake lever

This thesis presents the potential of hybrid polymer composites application made from short natural fiber/glass fiber reinforced thermoplastic composites for the development of automotive parking brake lever component. Concurrent engineering approach was implemented in the overall product development process which covers materials selection, concept design development, theoretical performance analysis and environmental impact assessment to achieve the required component structural strength for safe and operational performances. Analytic Hierarchy Process (AHP) method was first applied in the material selection process where kenaf natural fiber was confirmed as the most suitable candidate material for the hybrid polymer composites formulation. The materials selection process was continued using integrated Analytic Hierarchy Process (AHP) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) methods whereby polypropylene was found as the most suitable type of thermoplastic matrix to be used for the hybrid polymer composites formulation. For the concept design development process, a new integrated TRIZ-Morphological Chart- AHP method was used during the conceptual design stage of the hybrid polymer composites automotive parking brake lever component and concept design 2 was selected as the final design concept based on the product design specifications. Rule of Mixtures (ROM) and Rule of Hybrid Mixtures (ROHM) micromechanical models were later employed to predict the Young’s modulus of the short kenaf/glass fiber reinforced polypropylene composites where results show that positive hybridization effect was able to be achieved at minimum relative glass fiber content of approximately 87.5 volume percentage compared to kenaf/polypropylene single system for allvarying total fiber contents cases. Finally, the use of hybrid kenaf/glass fiber reinforced polypropylene composites also revealed better environmental performance through life cycle assessment analysis carried out using Ecoindicator 99 method at the end of the product development process. Results showed that approximately 20 percentage reduction of overall environmental impact is achieved by using hybrid kenaf/glass fiber reinforced polypropylene composites compared to glass fiber/polypropylene composites which further strengthened its potential for automotive parking brake lever application