**5. Conclusions**

**Figure 20.** Nodes selected for plotting the temperature gradient throughout the composite material thickness.

**Figure 21.** Composite temperature history.

38 Characterizations of Some Composite Materials

**Figure 22.** Bladder temperature history.

It can be concluded that both air and water provide similar curing temperatures for the composite laminate, however, the warm-up time is considerably different for the two convective mediums as it can be observed in the above presented results. Air is considerably slower in warming up the silicon bladder up to operating temperature. Once the aluminum tool and the silicon bladder are at operating temperature, the bladder thickness nor the convective medium have much effect on the overall curing process time. It is only until the very end that the different convective mediums display different curing rates.

Based on results of the simulation provided, the use of a snap cure epoxy binder, and an additional 90 second cycle to cool the part; It seems highly probable that parts can be formed in a hydroforming machine in approximately 10 min. With the addition of residual heat in the bladder and some process optimization it may be possible to reduce the actual cycle time 30% further to 7 min. Physical experiments are needed for validation.

A large hydroforming tray bed may be able to form 4–6 parts in one cycle. A 10-min cycle running 4 parts produces a 2.5-min average part cycle time. A 250 days' work year, running a 7-h shift would produce 42,000 parts per year. The envisioned ability to form and cure metal composite laminated parts in one single hydroforming process step has yet to be physically proven, but based on simulations it is highly promising. More in-depth study and physical models will be required to fully validate the process. However, based on the initial work completed, it seems viable to project, that a hydroforming machine can be used to form composite parts.

**6.2. Electroactive polymer (EAP)**

vibratory deicing or wing warping.

\*, Xiaochen Li1

California, California, United States

, Karl Neidert2

2 Patent Attorney, Karl Neidert and Associates, CA, United States

3 CTO, Ellis Industrial Design, San Diego, CA, United States

to-54-5-mpg-u-s-fuel-economy-rule-obama-says

stingrayanother-step-forward-for-composites

\*Address all correspondence to: bochengj@usc.edu

**Author details**

Bo C. Jin1

**References**

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May 7

Electroactive Polymer (EAP) is a polymer that exhibits a change in size or shape when stimulated by an electric field. The field generates coulomb attractive forces on the electrodes that apply compressive forces on the dielectric causing the change in size or shape. There are three primary types of EAP: Ionic, Piezoelectric and Dielectric. EAP can be used to create a variety of devices including sensors, actuators, and energy harvesting devices. Inclusion of EAP into composites laminate sandwich panels may have potential for a few excellent features such as

Out of Autoclave Metal and FRP Composites Thermo-Hydroforming

http://dx.doi.org/10.5772/intechopen.81600

41

and Michael Ellis<sup>3</sup>

1 Research Scientist, Aerospace and Mechanical Engineering, University of Southern

[1] Enprotech Hydroforming. http://www.enpromech.com/hydroforming-fluid-cell/

[2] Triform Hydroforming http://www.triformpress.com/?gclid=COel8ZXM7cYCFY17fg

[3] Grelling Keane. http://www.bloomberg.com/news/articles/2011-0729/automakers-agree-

[4] Composites World. http://www.compositesworld.com/blog/post/in-new-corvette-

[7] Kim HD, Brown GV and Felder JL. NASA Glenn Research Center Cleveland Ohio: Distributed Turboelectric Propulsion for Hybrid Wing Body Aircraft; 2008 July 24 [8] Rep. Pompeo, Mike. https://www.congress.gov/bill/113th-congress/house-bill/1848; 2013,

[9] Eigensatz M, Kilian M, Schiftner A, Mitra NJ, Pottmann H, Pauly M, Evolute Software. 2010. http://www.evolute.at/software-en/evolutetools-for-rhino, http://vecg.cs.ucl.ac.uk/

Projects/SmartGeometry/paneling/paper\_docs/panelization\_sigg10\_small.pdf

[5] Plasan Carbon Composites Corvette Marketing Materials http://plasancarbon.com [6] Conner, Monroe. http://www.nasa.gov/centers/armstrong/Features/leaptech.html

It also seems viable that a hydroforming machine is well suited to accommodate the high pressures required by some snap-cure resins such as HexPly M77. This particular resin requires a pressure of 80 bar (1160 psi). Over a large wide surface area, 80 bar will generate significant force. However, hydroforming machine are designed for much greater loads and would easily accommodate the level of pressure. The ability to co-form metal alloys and composite materials seems to be viable and is believed to be a topic worthy of additional study.

Vehicles produced for H.R. 4013 (IH)—Low Volume Motor Vehicle Manufacturers Act of 2014, 2025 CAFÉ Corporate Average Fuel Economy mpg target of 54.5 and the needs of General Aviation, advancement especially electric aircraft may attain benefits from this study.
