Page 47 - Engineering Plastics Handbook

Products and Design 21

panel should have high application potential in industries ranging from
building and construction to transportation to furniture. PEI/PES core
laminates are used for aircraft and railroad car interior panels. They have
a service temperature range from −194 to 180°C (−317 to 356°F) and fire
resistance. The core is primarily under shear stress on bending. The upper
skin is under compression stress, and the lower skin is under tensile stress.
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SP Systems developed Core-Cell , a structural foam composite based on
heat-stabilized SAN copolymer used for thermal and sound insulation [4].
The foam composite has high impact resistance and toughness, and it is
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thermoformable. Core-Cell was developed for marine applications, and
its applications extend to more transportation products. SP Systems (Isle
of Wight, UK) produces composites and technology for core materials and
services including structural design and process engineering. The company
was a force in converting from aluminum to fiberglass-reinforced unsatu-
rated polyester (FRP) for boat hulls. An analogy, looking “back to the
future,” is to convert the decades old, aluminum honeycomb before expan-
sion (HOBE) used in airframe construction to HOBE using engineering
thermoplastics.
Fundamental design equations are given in this chapter. More complex
models use calculus, linear finite element analysis (FEA), and CAD/CAE.
Linear FEA for structural analysis and testing is used with elastic mate-
rials, which includes plastics in the elastic region and metals. Nonlinear
FEAis used with elastomers because these materials have no stress-strain
curve linear portion. Linear FEA uses Young’s modulus and Poisson’s
ratio. Data for Young’s modulus are more abundant than for Poisson’s
ratio. Three-dimensional modeling FEAcodes and finite element modeling
(FEM) services are provided by

1. Algor Inc., Pittsburgh, Pa., USA
2. Abaqus Inc., Pawtucket, R. I., USA
3. Ansys Inc., Canonsburg, Pa., USA
4. ATA Engineering Inc., San Diego, Calif., and Herndon, Va., USA
5. Engineering Mechanics Research Corporation, Troy, Mich., USA
Algor software and services include manufacturing execution systems
(MES) software that combines large-scale motion and stress analysis of an
FEM model in a single process, simulating real-world deformation and fail-
ure analysis, and “Superflow,” a CAD-like program for high-precision FEM
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modeling. ABAQUS/Standard is used for solutions of traditional implicit
FEA of static, dynamic, and thermal properties, and it is integrated with
third-party software for injection molding analysis. Ansys DesignXplorer
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VT is used by designers of engineering plastics products addressing mul-
tiple competitive objectives including geometric CAD, ANSYS ParaMesh™,