Completely automatic weight-minimization method for high-speed digital computers

This paper presents a step-by-step procedure, related to the method of steepest descent, for the weight minimization of an arbitrary structure and, as an example, applies it to optimizing the weight of a simple cantilevered box. The procedure presented is capable of handling limiting conditions placed upon the stresses or deflections at selected points and is, in general, applicable to any single-extrema type of continuous function. It is assumed that a procedure or program exists—'the stiffness-matrix method being ideal for this purpose—-for calculating stresses and deflections, etc., at specific points under various load conditions, once the defining structural parameters are known. Hence, only auxiliary calculations needed to interpret output from and prepare new input for such a program are discussed. Furthermore, the input is assumed to vary continuously, and the subject of discretely varying arguments, as well as multiple extrema, is considered to be outside the scope of the present paper.