Optimum jack loads for static and fatigue tests

An automated procedure used at the Northrop Grumman Corporation to determine the jack loads for static and fatigue structural tests is described. The procedure includes a recently developed method to automatically compute jack loads that satisfy jack-capacity and Jack-direction constraints, while providing a best fit to known internal moment, shear, and torsion loads. The engineering steps required to salve this problem have been automated and integrated with the optimization procedure. Compared with the semimanual approaches generally used in the industry, the new method has saved one-third to one-half of the engineering time required to determine the Jack loads on the A-6E and C-2A aircraft fatigue tests while, providing a better lie to the moment, shear, and torsion loads.