ABSTRACT
ABSTRACT: Morphological indicators are dimensionless numbers that represent a property of a structure (e.g. volume, stiffness . . .) and depend only on a small number of variables (Samyn, 1999). These indicators allow for optimization at the stage of conceptual design. The most important indicators are the indicator of volume, related to the strength of the structure, and the indicator of displacement, related to the stiffness of the structure. These indicators, in their most simple appearance, are function only of the geometrical slenderness of the structure, under the assumption that the structure is not subjected to second order effects and that shear effects are not predominant. The indicator of volume allows choosing the structural typology with a minimum of volume of material. When using the indicator of volume at the stage of conceptual design, important areas of slenderness appear to bring about problems of resonance. This is particularly the case for structures which have predominant co-vibrating loads, have large spans and are using a material with a small stiffness/strength ratio. A practical example is discussed and some general design guidelines are proposed.
