Duocel® Foam Energy Absorbers
- -Cost Effective
- -High Strength
- -Atmosphere Corrosion Resistance
- -High Temperature
Why would you use a Duocel® foam energy absorber?
Duocel® foams are also open-celled, so they do not hermetically trap gasses that can create a pneumatic "spring "effect at low impact velocities or create rebound. At very high velocities, there is a fluid flow friction effect as the entrained gas is rapidly squeezed out of the open-celled foam structure. In this case, there is still no effective spring-back, but the increased initial resistance can provide a convenient "crush plateau enhancement" if the impact is at a much higher velocity than anticipated. If this feature is intentionally incorporated into the design, it can be controlled by selection of the foam pore size and airflow resistance.
Who uses Duocel® foam energy absorbers?
Duocel® energy absorbers are commonly used in aerospace and military applications where operational performance is critical, and the storage, use, and operational environmental conditions are likely to be severe.
There are a number of foam mechanical characteristics, but next to modulus, the most frequently used is the crush strength or plastic yield strength. When a load is applied to a foam structure, it will initially yield elastically in accord with the Young‘s modulus equation.
However, at approximately 4-6% of strain, depending on the sample size, the foam structure will begin to buckle and collapse continuously at a relatively constant stress. Depending upon the initial relative density of the foam, this constant collapse will proceed to approximately 50-70% of strain.
At that point, the stress / strain curve will begin to rise as the compressed foam enters the "densification" phase. The point in the stress / strain curve where it transitions from the elastic to plastic deformation phase defines the "crush strength" of the foam. This is an important mechanical parameter as it is obviously essential to remain below that level for any structure that is being designed to maintain its shape under design load.
For a more in depth explanation of how Duocel® performs in energy absorber application visit our technical data page on energy absorption.