Contour Assessment of Formed Wing Panels

A procedure has been developed which utilizes finite element analysis methods in the contour assessment of formed wing panels. The procedure utilizes a finite element model reflecting the bi-directional stiffnesses of the panel in conjunction with local deviations from contour derived from reported inspection data. Final assembly fit-up forces are predicted and compared to the maximum allowable fit-up forces specified on the engineering drawing. The procedure also provides for the determination of local gap conditions with the panel subjected to the allowable fit-up forces. The local gap conditions are compared to the shimming allowances specified on the engineering drawing. These comparisons provide a basis for ascertaining the necessity for contour adjustments. Early detection of the need for contour adjustment minimizes the schedule impact and cost of the rework.