ESDU STRUCT 02.01.17
Nomogram for strength of stringers in panel in compression.
Abstract:ESDU Struct 02.01.17 gives a nomogram that represents the method of ESDU Struct 02.01.16 for the determination of the edge stress at failure of a stiffened panel under compression. The presentation of the latter document introduced the relation between the edge stress and the average stress in the panel taken from ESDU Struct 02.01.03 in an approximate manner that is avoided in the presentation used here. As in ESDU Struct 02.01.16, the data yield the ratio of the edge stress at failure to the stress at failure of the stringer alone flexing normal to the sheet; the latter stress may be obtained from ESDU Struct 01.01.01. That stress ratio is a function of the ratio of the stringer to sheet cross-sectional areas, the ratio of the stringer section moments of inertia taken about an axis through its centroid and an axis in the midplane of the sheet, and the ratio of the sheet buckling stress (obtained from ESDU 72019) to the edge stress. Thus the calculation is an iterative one. The data in ESDU 76016 may be used to correct the results for the effect of yielding. The method takes into account the effect of buckling of the sheet on its contribution to the flexural stiffness of the stringer, but the effects of different buckling forms for the stringer and panel and of inter-rivet buckling are ignored; this is permissible for panels in which the sheet thickness is less than that of the stringer. A fully worked example illustrates the use of the nomogram and the other ESDU documents.
|Data Item ESDU STRUCT 02.01.17|