Stability of honeycomb sandwich panels in shear

CoA Note No. 55

ISCHE HOGESCHOOL VUEGTUIGEOUWKÜNDE Kanaalstraat 10 - DELFT

12

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THE COLLEGE OF AERONAUTICS

CRANFIELD

STABILITY OF HONEYCOMB SANDWICH

PANELS IN SHEAR

by

TECHNISCHE HOGESCHOOL VLIEGTUIGBOUWKUNDE Kanaalstraat 10 - DELFT NOTE Nö. 55 OCTOBER 1956 T H E C O L L E G E O F A E R O N A U T I C S C R A N F I E L D

The Stability of Honeycomb Sandwich Panels in Shear Abstract of the Thesis by R. Nichols, presented May 1955o

This abstract presents the results obtained by theoretical and experimental methods for the buckling of

honeycomb sandwich panels in shear. Details of the specimens analysed are shown in Figs. 1 and 2. The test rig is shown

in Fig. 3» and the accuracy v/ith which uniform shear was

obtained is illustrated in Fig. k* The experimental results are given in Fig. 5» where buckling and failing shear stresses are plotted against the ratio panel width "b" to panel

thickness "d". No consistent effect attributable to the difference in face thickness for the panel series A and B is shown by these results. Comparison betv/een theory and experiment is shown in Figs. 6 and 7* The results for buckling agree substantially v/ith plate theory for the case

of simply supported edges» Corrections of plate theory to allow for shear flexibility of the filling can virtually be neglected. Discrepancies between theory and experiment for b/d < 80 are probably due to an insufficiently accurate

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F I G U R E 4 - DISTRIBUTION O F SHEAR S T R E S S ON P A N E L NO. 3A. AT A SHEAR LOAD O F

3 4 , 0 0 0 3 0 , 0 0 0 Z if) ifi Ui oc H er < UJ I te> A D ^ 2O1OOO

KEYt-_ O BUCKLING STRESS OF A SERIES PANELS X FALING STRESS OF 'A' SERIES R^NELS A BUCKLING STRESS OF B SERIES PANELS Q FAILING STRESS OF *B'SERIES PANELS

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CURVES OF BEST FIT ARE DRAWN

10 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 IOO liO I20 I30 I 4 0

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FIG. 5. EXPERIMENTAL BUCKLING &

FAILING STRESSES.

SERIES PANELS'-FACES OOIS" THICK- MATERIAL D.T.D. 5 4 6

34^000 3 4 , 0 0 0 30,000 JD I U) U) UI o: cc < UJ I in OOOO

O lO 20 30 4 0 50 60 70 80 90 lOO IIO I20 I30 I40 O 10 2 0 30 4 0 5 0 6 0 70 8 0 9 0 lOO IIO I20 I30

FK». 6 . COMPARISON OF EXPERIMENTAL & THEORETICAL RESULTS ( V SERIES PANELS~ FACES O O B " T H I C K )

FIG. 7. COMR^RISON OF EXPERIMENTAL & THEORETICAL RESULTS QB'SERIES PANELS'^FACES 0 - 0 0 6 THIO^

K E Y :

-b o WIDTH O F PANEL 3 0 "

d = DEPTH OF FILLING BETWEEN MEDIAN PLANES OF FACES

A EXPERIMENTAL BUCKLING STRESS

X EXPERIMENTAL FAILING STRESS

THEORETICAL BUCKLING STRESS FOR PANEL HAVING CLAMPED EDGES-EQUIVALENT PLATE THEORY

THEORETICAL BUCKLING STRESS FOR WVNEL HAVING SIMPLY SUPPORTED EDGES-EQUIVALENT PLATE THEORY

CORRECTED EQUIVALENT PLATE THEORY FOR SIMPLY SUPPORTED PANEL