**2.3. Technical objective**

This project seeks to gain a foundational understanding of the proposed thermo-hydroforming machine's performance by conducting FEA simulations [38–40]. This simulation studies a multiply coupon of carbon fiber prepreg being formed by a vulcanized silicone elastomeric bladder. The bladder is heated and pressed into the composite coupon by water heated to 285°F under 300 psi of pressure. The tool is pre heated to the temperature of 285°F as well. As a result, the composite coupon is heated from above and below. This process should be used comfortably to 425°F (218°C) and 10,000 psi/700 Bar.

We understand from work by Globe manufacturing, Quickstep Composites and other prior art that both air and fluid heat behind a membrane can be used to react and cure prepreg materials. It is also known that pure water has one of the best thermal conductors. Water has a thermal conductivity that is 24 times greater than that of air and that circulating water increases this effectiveness even further by a factor of 10. Our objective is to study the viability of adopting these methodologies to hydroforming.

Hydroforming has a well-documented history of safely forming sheet metal materials at pressures of up to 20,000 psi (137.89 Mpa) well beyond the requirements of composite materials. Because hydroforming machines can deliver and contain high fluid pressure, it is believed that the addition of a thermal cycle to heat & cool the forming chamber's working fluid will enable a significant industrial advancement in sheet hydroforming machines. The new methodology will allow for a single machine to shape, catalyze and cure prepreg composite materials, thermal plastics and matrix materials in addition to its traditional use as a metal forming machine.

With FEA simulations demonstrated, qualitative assessments can be made to facilitate the future validity for development, implementation and commercialization of thermo-hydroforming machinery.
