Werden gewichtsoptimiert konstruierte Bauteile durch die Verwendung von Leichtmetallen wirklich leichter: Fid-Bau Portal

Werden gewichtsoptimiert konstruierte Bauteile durch die Verwendung von Leichtmetallen wirklich leichter

Neumann, P.

In transportation and many other technologies weight reduction brings about economical and environmental advantages. Therefore, materials are increasingly judged according to their weight saving potential. In the case of structural materials, which have to withstand given stresses, a classification based on specific gravity alone (light metals) falls short. The crucial parameter is the ratio between density and strength. In the case of parts loaded in bending the situation is complicated by the fact that e.g. the elastic stiffness of such parts (of a given length) does not only depend on their volume but also on their shape. It is shown in this paper that the usual comparison of different materials under bending loads to obtain the weight saving potential is strongly shape biased, favoring the more compliant material. If the comparison is made under the condition of equal external dimensions, the same merit parameter, which applies for uni-axial tension also applies for parts loaded in bending. As a result it becomes obvious that the weight saving potential of high strength steels and aluminium alloys are comparable - not only in the uni-axial tension but also in bending.