11.4 Common Cushion Methods and Their Features
371
Fig. 11.3 Aluminum
honeycomb absorber.
1-Outer tube; 2-Aluminum
honeycomb; 3-Inner tube
test of aluminum honeycomb, the direction of the impact force should be in line with
the longitudinal axis of aluminum honeycomb as shown in Fig. 11.3.
In dynamic impact test, ballast weight was installed on the test device and dropped
down to the aluminum honeycomb article. The response acceleration on center of
gravity of the ballast weight was acquired. Motion equation of the ballast weight is
as follows:
m ¨
y = F − mg
(11.1)
where, m is the mass; ¨
y is coordinate of the center of gravity; F is damping force of
the aluminum honeycomb; g is acceleration of Earth gravity.
According to Eq. (11.1), the damping force F can be given by the formula:
F = m ( ¨
y + g)
(11.2)
A typical curve of load to deformation of aluminum honeycomb is shown in
Fig. 11.4. It could be seen that the load almost remains as a constant during plastic
deformation procedure. Meanwhile, at the beginning of compression, there was a
peak load, which could be effectively avoided with a pre-compression before use.
Fig. 11.4 Typical experiment result of aluminum honeycomb material