The paper is concerned with the use of algebraic linear programming for the minimum weight design of steel portal frames subject to the constraints of the Kinematic Theorem of plastic collapse. Minimum weight design is a classic linear programming problem which can be solved algebraically for classes of frames with arbitrary geometric dimensions and arbitrary load magnitudes. In a recent paper, the process of algebraic linear programming was reduced to the repeated application of a number of vector formulas and a computer program was developed for the derivation of the solution chart for specified classes of frames. In this paper the method is extended to the problem of frames subjected to multiple load cases. It is shown that a simple problem whose solution can normally be displayed in the form of a two-dimensional chart now requires a three-dimensional chart or three two-dimensional charts. For a more complex problem the change to multiple load cases results in a large increase in computational effort in the chart derivation procedure and it too results in a three-dimensional chart.

purchase the full-text of this paper (price £20)

go to the previous paper
go to the next paper
return to the table of contents
return to the book description
purchase this book (price £60 +P&P)