In recent years, the amount of research on natural fibres and natural-fibre-based products has increased substantially. The reason for this increase is due to a greater awareness of the environment and the ever depleting trend of petroleum supplies. Natural fibre composites and in general, natural fibres have a big role to play towards a sustainable environmentally friendly future. The automotive industry is taking big steps toward a more eco-friendly product chain by implementing natural fibres as a base for making various components, such as seat backs, door panels, spare tyre and boot linings. The world production of natural fibres is increasing since the product base is increasing. Each year, more synthetic fibres and high energy consuming products are being replaced by natural-fibre-based products. The reason for this trend is not only due to an increased environmental awareness but also because natural fibres have excellent properties, such as light weight, and they have relatively low costs. This study attempts to review the most commercially important natural fibres and their automotive application and also looks at the properties, chemical composition and cost of some natural fibres being used in industry.

Population growth, urbanization, industrialization, and increased socioeconomic activities have escalated carbon dioxide (CO2) formation and concentration

This work provides a comprehensive review of numerical simulation and optimisation of the shot peening found in the existing literature over the past 10 years. The review found that the developed numerical models coupling finite elements with discrete elements became increasingly mature and showed their advantages in incorporating flow behaviour and randomness of shots. High emphasis must be placed on the constitutive equations of target material where its strain-rate sensitivity, cyclic behaviour and Bauschinger effects are recommended to be incorporated in the numerical material model simultaneously since considering one of them in isolation may lead to unreliable distribution of residual stresses. Furthermore, material hardening is a critical benefit of shot peening; however, it has not received its deserved attention from the existing investigations, neither in simulation nor in optimisation. The study found that intensity and coverage are two critical control parameters recommended to be constraints for optimisation of shot peening. Finally, this work also found that developed heuristic algorithms, such as genetic algorithms have recently showed their advantages for searching optimal combinations of peening parameters. It is plausible that in the near future, the synergy of combining these algorithms with approximation models can be expected to gain more attention by researchers.