The Deflexion of an Elastic Structure

The Hardy Cross, or Moment Distribution, method of frame analysis offers interesting possibilities, when used on an automatic digital computer. For a number of years the analysis of elastic hyperstatic frames by computer has been mainly carried out by methods which require the explicit solution of large sets of simultaneous equations. If conventional techniques are used to solve the equations, the storage space required in the memory of the computer is approximately proportional to the square of the number of joints in the frame. This means that in practice, with present-day computers, only relatively simple frames can actually be analysed by these methods.

THE PRESIDENT proposing a vote of thanks to the author, said the subject was fascinating and the Institution was extremely grateful to Mr. Kell for his paper.

Mr. M.Z. COHN The background of Professor Neal's paper is to outline a very interesting property of redundant structures, which consists in conserving constant deflexions at the point of collapse, above a definite critical value of joint (or support) flexibility.