After I had implemented my beam model (in plain FORTRAN 77, of course), we (i.e. the ski manufacturer) produced some skis made of purely metal layers (to be more specific steel and aluminium layers). Why that? The material properties (i.e., the thermal expansion factor and the mechanical stiffness parameters) of metals at these low temperatures (low for metals) are very well known. Hence, we could use the very first experiments to identify the gluing temperature.
With that temperature fixed, we were able to reproduce the results of all metal ski experiments (different number of layers, different thicknesses, different order of materials) within a tolerance of less than 5 percent. The computing time for one experiment was about 3 minutes on a central IBM monster machine at Linz university (with a computing power much lower than today's cellphones).
|Image Sourece: European Patent Office, Patent Nr. 0086983. This patent has nothing to do with our developments.|