Computer techniques are applied in all areas of vehicle design
having an influence over the speed of the design process and the
efficiency and coherence of the design itself. The deployment of
analytical methods removes the need for some test work and changes
the role of much of the rest.
A restraint system design has implications for several vehicle
areas: body design; seat design; interior trim and hardware; and
steering system; and must be considered against all these as well
as the structural crashworthiness of the vehicle.
At the concept stage, computer methods outline the implications
of the functional specification so it can be modified if found to
be unreasonable or inconsistent. As the vehicle design progresses,
the requirements of the restraint system are broadly defined using
programs to assess comfort and dynamic performance.
Initial sled test work is based on the realistic possibilities
as determined from the dynamic simulations, and the results of
these tests serve to refine the model and improve background data.
These tests are deliberately kept simple, and the computer model is
used to study the effects of different impact conditions and
component designs. This information is fed to design areas. This
sequence of test and simulation is repeated in conjunction with
prototype vehicle tests. The process means that sled tests have
been effectively used and their combination with computer
simulations gives a better understanding of, and confidence level
in, the restraint system performance in the full vehicle test.