Shock absorber - cluster of 4 airbags.
Impact with horizontal plane.
The cluster of airbags is very effective shock absorber if the orientation
of payload before the impact is unknown in advance. The payload is usually
squeezed between bags to prevent the direct contact with the ground surface.
As a result, the overload can be diminished by dozens times. When solving
this dynamic problem, the contact bag-bag, bag-payload and bag-surface
must be taken into account, as well as adiabatic internal process in each
bag. The program MONSTR-2.2 easy copes with
such task even using home PC. In example above (~1000 finite elements)
the preprocessing takes 10min and computing 12min. The mass of internal
gas was allocated in finite elements nodes. The scale in each picture was
chosen to fit airbags in frame. The lower boundary of frame coincides with
the horizontal contact surface.