Non-form-active elements are those whose active element when subjected to the uniformly
longitudinal axis does not conform to the form- distributed load (Al ,5c).
active shape of the loads and are such that no Because they are not subjected to bending
axial component of internal force occurs. These stress, elements with form-active shapes are
contain bending-type internal force only. Semi- potentially the most efficient types of struc-
form-active elements are elements whose ture. Non-form-active elements are potentially
shapes are such that they contain a combina- the least efficient because bending stress is
tion of bending and axial internal forces. The the principal type to which they are subjected,
cranked-beam shape in Fig. Al .5 is a fully-form- The efficiency of semi-form-active elements
active element when subjected to the two depends on the extent to which they differ
concentrated loads (A1.5b) but a semi-form- from the form-active shape.Structural Design for Architecture
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