Solution: Our metamaterial solution lines, including MetaCORE, MetaCORE-LD, and MetaTHERM.
Metamateral ID: Reference number for specific metamaterial solution configuration.
Crush Force Efficiency (CFE): CFE is the ratio of the load (force per unit area) when crushing begins, Fcrush, to the load during the compression, Fcompression:
When CFE = 1, the impact decelerations are mitigated. When CFE becomes smaller and approaches 0, sudden changes in acceleration are transmitted through the material, causing trauma (e.g., head and neck injury) or damaging cargo.
Density: Mass per unit volume.
Flexural Modulus: The ratio of stress to strain for a beam under flexural deformation, which is often measured in a 3-point bending test.
Material: Core base material.
- PLA: Polylactic acid
- ASA: Acrylonitrile styrene acrylate
- CF-PP: Carbon fiber reinforced polypropylene
- CF-PLA: Carbon fiber reinforced polylactic acid
- CF-PETG: Carbon fiber reinforced polyethylene terephthalate glycol
- PC-ASA: Polycarbonate blended with acrylonitrile styrene acrylate
- GF30-PA: Glass fiber reinforced polycaprolactam (Nylon)
- CF30-PP: Glass fiber reinforced polypropylene
Max. Displacement: When a sandwich panel is loaded, it can withstand a maximum deflection related to its peak force and flexural modulus.
Peak Force: When a sandwich panel is loaded, it can withstand a load up to the peak force. Loads above the peak force activate a failure mode. Which failure mode is activated depends on a number of factors, but can be easily determined by looking up the sandwich panel’s failure mode map. For example, here is the failure mode map for MetaCORE-LD compared to that for Steel + HDPE.
Specific Energy Absorption (SEA): The SEA is the integrated area under the load-compression curve divided by the mass of the material that’s become crushed. A large SEA (> 20 kJ/kg) means lots of energy has been absorbed by the material on impact or that the material absorbing the impact is very lightweight. Many lightweight, high SEA materials are functional in one direction, meaning they have low SEA in the other two directions. Therefore, off-axis impacts are generally not effectively dissipated. MetaCORE is a pro-isotropic high-SEA metamaterial, which sidesteps the uncertainty of knowing the impacting direction.
Strength: The maximum stress the material can bear and signals a transition to irreversible failure.
Test method: Information about how material properties were measured. Some measurements, like the stiffness of a composite sandwich panel, are size dependent.
Young’s Modulus: The modulus of linear elasticity relating stress and strain.