Structural designers today have access to advanced core materials for construction projects. Sandwich composites with core filling deliver strength and stiffness that exceed conventional building methods. The right core material improves durability and reduces weight.

What Are Core Materials

Core materials sit inside a sandwich construction as the “filling” that connects two stronger skins. Sandwich composites get built by adhering outer skins like fiberglass or carbon fiber around a lightweight core.

Core materials differ from frameworks like rebar or studs in a few key ways:

• Cores run the entire span between sandwich skin layers to provide stability and stiffness. Frameworks form disconnected networks that leave areas unsupported.
• Cores prevent the skinny outer skins from buckling inwards by propping them up. Frameworks rely solely on thick outer layers for strength.
• Cores also insulate sandwich structures from noise, vibrations and heat more effectively than air pockets within frameworks.

Common core materials include polymer foams, balsa wood, aluminum honeycomb and composite honeycombs. Each core type serves different applications depending on required properties.

Benefits of Cores in Sandwich Structures

Quality core materials lend useful traits to sandwich constructions:

• Strength & Stiffness: Cores spread applied loads evenly across both outer skins to resist bending and distortions. The composite resists forces better with less material.
• Light Weight: Thin yet rigid skins separated by lightweight cores form sturdy structures without excess weight. Weight savings reach 60% for some foam and honeycomb applications.
• Insulating Properties: Closed-cell polymer foams inhibit heat flow for fire resistance and control temperature swings. Acoustic foam dampens noise.
• Corrosion Resistance: Structural polymer foams and honeycombs withstand moisture, oils, and solvent contact. Sandwich composites prevent deterioration from chemicals or water.

Optimized core selection tailors sandwich constructions to handle expected structural, thermal and acoustic environments.

Honeycomb Core Composites

Honeycombs take advantage of hexagonal cells to deliver the highest strength-to-weight ratios among core materials. The networked walls reinforce the structure’s stiffness and resistance to compression, vibration and shear forces.

Nomex honeycomb gets constructed out of aramid paper that offers great strength with minimal weight. According to the experts at Axiom Materials, Nomex honeycomb comprises half the density of aluminum options for even better lightweight properties. The aramid honeycomb withstands continuous use temperatures over 750°F to serve extreme environments.

Common applications exploiting honeycomb cores include aircraft doors, panels and spoilers along with yacht hulls, solar panels and satellite equipment. Using the lightest yet strongest core materials keeps performance high while cutting construction expenses.

Applications Using Advanced Core Materials

Optimized sandwich core composites create structures that outlast conventional builds:

• Bridge Decks & Roads: FRP deck skins over balsa cores form pothole-resistant driving surfaces that withstand heavy truck loads and extreme weather.
• Rail Cars: Stainless steel skins enclosing PU foam cores resist dents while providing noise isolation and heat insulation for freight containers.
• Aircraft: Carbon fiber skin and Nomex honeycomb constructs create stiff wing and body components that meet aerospace standards at less overall weight.
• Boats & Ships: Glass fiber skins over PVC foam core produce buoyant, composite hulls and decks that prevent corrosion and rotting issues.
• Stadium Roofs: ETFE membrane and polymer foam roofs retain lightweight flexibility to retract open while providing durable weather protection.

Conclusion

Structural designers today have access to advanced core materials for construction projects. Sandwich composites with core filling deliver strength and stiffness that exceeds conventional building methods. The right core material improves durability and reduces weight. As new core materials and sandwich composite manufacturing techniques emerge, we can expect to see even greater adoption across diverse industries. From transportation to infrastructure to specialty industrial applications, optimized core composites enable previously impossible design capabilities and performance characteristics.