Chapters authored
Out of Autoclave Metal and FRP Composites Thermo-Hydroforming
In this chapter, we explore a novel type of thermo-hydroforming process conceived to expand the role of sheet metal hydroforming machines from one of just forming sheet metal materials into one of being able to form multiple materials. This work specifically focuses on the use of thermohydroforming to shape and thermal catalyze prepreg composite sheets into rigid parts of complex 3D geometry. Elastomeric Sheet Hydroforming is an excellent low-cost manufacturing method requiring a single tool die on only one side. The mating die is a flexible membrane backed by fluid under high pressure. Various designs configurations exist that allow for significant pressure levels of up to 1400 Bar (20,000 psi), to be contained. The cycle life of the containment vessel components is commonly designed to accommodate up to 1 million cycles of use over 40 years. However, these machines can be expensive ranging in cost from several hundred thousand up to $6 million dollars. Expanding the market scope and potential of the press by enabling them to also form composites will provide benefit to both the machine owners and their customers. The intent of this project is to advance the state of the art in composites forming by demonstrating through FEA modeling that a hydroforming machine can be potentially configured to form thermally catalyzed prepreg composite panels. It is believed that the concept in like manner, will also be applicable to forming metal-composite hybrid panels, stratified metal thermoplastic laminates, thermoplastic synthetic granites and of course sheet metal materials. This concept seeks to benefit the American Manufacturing Industry and create jobs in the U.S. by providing a low-cost method for manufacturers to produce medium to very large sized high-quality sheet composite parts of an advanced nature in construction. This application is for operations requiring volumes less than 30,000 forming cycles per year per machine. Processes currently exist in the industry that utilizes heated air or heated glycol to form sheet materials. However, this process seeks to offer greater benefit by using pure water as a high thermal conductivity working fluid in a scheme that offers vastly elevated pressure during forming and curing cycles.
Part of the book: Characterizations of Some Composite Materials