Andrea Chiarenza

My area of interest covers innovative materials and additive manufacturing methods, which inspired me to research an innovative idea for a consumer product that might be potentially improved by this solution: a surfboard. The combination of Functionally Graded Materials and Additive Manufacturing aims to improve the performance of several products currently available in the market. The research has been performed using virtual simulation, specifically CAD and FEA software.

Despite the disruption caused by the COVID-19 pandemic, the quality of human and technical support offered by the University of Derby has been outstanding. My future plans include a continuous improvement of my technical knowledge and set of skills. Thanks to my degree, I am now working as engineer for a multinational manufacturing corporation.

Performance Analysis of a Surfboard with Functionally Graded Additive Manufactured Core

When it comes to technological innovation, Functionally Graded Materials (FGM) play a unique role as they enable to combine the irreconcilable properties of sandwich structures and solve most of their typical issues. The concept of topology optimisation allows the creation of high-performance structures by strategically rearrange their density. This can be achieved by current Additive Manufacturing (AM) solutions, that overcome the limitations of traditional manufacturing methods. This project presents an innovative surfboard featuring a functionally graded core, focusing on the benefits that make this board stand out among its traditional counterparts. Furthermore, special attention is dedicated to the great level of customisation and sustainability of this solution, allowing the surfers to fully enjoy a high-performance product, with no compromise on surfing experience or environmental concerns. This project highlights the improvement in the performance of a surfboard brought by a functionally graded honeycomb core and sets the foundation for future analyses and potential commercial applications.

Background

• Sandwich structures are used when high strength-to-weight and stiffness-to-weight ratios are required​
• Functionally Graded Materials (FGM) show a multi-directional variation of the composition of the core material, resulting in higher mechanical performance and a smoother stresses distribution profile
• Bio-adaptable implants that mimic the shape of natural bones are examples of FGM​
• Additive Manufacturing (AM) allows to create structures with variables internal density, unachievable via traditonal processes

Problem

• Surfboards are an example of sandwich composites​
• Their main issues are related to the longevity and to a lack of customisation of the board​

Aim

• Highlight the benefits of Functionally Graded Additive Manufacturing (FGAM) to the mechanical performance of a surfboard. The surfboard features GFRP face sheets.

Objectives

• Material selection for the FG core​
• Design of a FG core​
• Simulation and performance assessment​

Core material selection

• The Ashby approach was used as a framework for the material selection process​
• Material indices for a stiff and strong surfboard with mass minimisation were calculated​
• Constraints on mechanical performance, manufacturability and external conditions were applied​
• Polylactic Acid (PLA) was found as the best material candidate to manufacture a FG core for the surfboard

Design

• Different configurations of surfboard were designed on SolidWorks
• Preliminary simulations on model featuring a solid PLA core allowed to evaluate the most stressed areas of the board under a three-point bending test

Effective properties of the honeycomb core

• A honeycomb structure was adopted for the surfboard core​
• The mechanical properties of the homogenous honeycomb structure were calculated through a tensile test on a rectangular beam model​
• The same test was performed on a specimen featuring a functionally graded honeycomb structure. The topology optimisation allowed to redifine the structure to improve the mechanical performance of the component
• The values obtained were then applied to the surfboard model​

Results

• The FG honeycomb core allows a reduction of shear stress at the core level of eight times compared to a solid core and 31% compared to a homogeneous honeycomb core​

Manufacturability

• The PLA FG core can be created via Fused Deposition Modeling (FDM)​
• The use of modular unit cells increases the flexibility of the manufacturing process​

Recyclability

• The use of PLA for the core and Epoxy resin for the interface considerably reduce the environmental impact of the board​

Download Andrea's project overview poster (PDF) (this pdf document is not fully accessible but the contents within it can be viewed via the content on this page)