MODIFIED FULLY UTILIZED DESIGN (MFUD) METHOD FOR STRESS AND DISPLACEMENT CONSTRAINTS

The traditional fully stressed method performs satisfactorily for stre ss-limited structural design. When this method is extended to include displacement limitations in addition to stress constraints, it is know n as the Fully Utilized Design (FUD). Typically, the FUD produces an o verdesign, which is the primary limitation of this otherwise elegant m ethod. We have modified FUD in an attempt to alleviate the limitation. This new method, called the Modified Fully Utilized Design (MFUD) met hod, has been tested successfully on a number of problems that were su bjected to multiple loads and had both stress and displacement constra ints. The solutions obtained with MFUD compare favourably with the opt imum results that can be generated by using non-linear mathematical pr ogramming techniques. The MFUD method appears to have alleviated the o verdesign condition and offers the simplicity of a direct, fully stres sed type of design method that is distinctly different from optimizati on and optimality criteria formulations. The MFUD method is being deve loped for practicing engineers who favour traditional design methods r ather than methods based on advanced calculus and non-linear mathemati cal programming techniques. The Integrated Force Method (IFM) was foun d to be the appropriate analysis tool in the development of the MFUD m ethod. In this paper, the MFUD method and its optimality are examined along with a number of illustrative examples. (C) 1998 John Wiley & So ns, Ltd.