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Mechanical analysis of thermo-hydroforming of a fiber-reinforced thermoplastic composite helmet using preferred fiber orientation model

The composite thermo-hydroforming process, utilizing heated and pressurized fluid, was used to form an advanced helmet with the Spectra Shield. Experimental results obtained from the forming process show that thermo-hydroforming is a feasible process for manufacturing thermoplastic composite materials. Concurrent to the forming experiments, the forming process was numerically modeled using ABAQUS/CAE. The behavior of the fiber reinforced polymer composite was modeled using the Preferred Fiber Orientation model, which was implemented into the explicit finite element code ABAQUS by writing a User Material Subroutine. The preferred fiber orientation model was further adapted to work with a composite laminate consisting of multiple layers. Numerical results were compared with experimental data to validate the method in terms of predicting the deformed geometry of the multilayer composite, wrinkling, as well as the punch force–displacement curve. Overall, the deformed shape of the fiber-reinforced thermoplastic composite helmet, including the distribution of wrinkles were predicted accurately.