Stresses in Aircraft and Shell Structures

460 Pages·1956·24.023 MB·English

by  Paul Kuhn

STRESSES IN AIRCRAFT
AND SHELL STRUCTURES
Nuatta)
BicceleWieLUinem ereceeo)iDNemes
eeeOMe cn
ro

McGRAW-HILL PUBLICATIONS IN AERONAUTICAL SCIENCE
Jerome C. Hunsaxer, Consulting Editor
STRESSES IN AIRCRAFT AND SHELL STRUCTURES
McGRAW-HILL PUBLICATIONS IN AERONAUTICAL SCIENCE
Jerome C. Hunsaxer, Consulting Editor
Draren, McKay, ano Lees:Instrument Engineering
Vol. 1 Pundamentale
Vol. 2 Mathematics
Vol. 3 Applications
Part 1 Measurement Systems
Part 2 Control Systems
Ktcuemann anv Weer: Aerodynamics of Propulsion
Kuuw:Stresses in Aircraft and Shell Structures
Suatno:Principles of Helicopter Engineering
Suaw anv Macks: Analysis and Lubrication of Bearings
Srreerer:Fluid Dynamics
VON Mises: Theory of Flight
STRESSES IN AIRCRAFT
AND SHELL STRUCTURES
PAUL KUHN,B.S. (Ac.E.)
Assistant Chief, Structures Research Division
National Advisory Committce for Aeronautics
McGRAW-HILL BOOK COMPANY, INC.
New York Toronto London
1956

STRESSES IN AIRCRAFT AND SHELL STRUCTURES
Copyright © 1956 by the McGraw-Hill Book Company,Inc. Printed in the
United States of America, All rights reserved. This book, or parts thereof,
may not be reproduced in any form without permission of the publishers.
Library of Congress Catalog Card Number 55-1174
THE MAPLE PRESS COMPANY, YORK,PA.
This book is dedicated
to myteachers
in the arts and sciences of structures
Proressor S. TimosienKo
and
Proressor J. A. Van Den Broex

PREFACE
Aircraft engineering is generally acknowledged to have given a great
impetus to research in structures. Much of this researchwork, however,
ia available only in the form of original papers, a form which renders the
results rather ineffective. This book represents an attemptto correlate
and unify a certain amountof work and to makeit more effective by
making it readily accessible.
The aim of the work may be described most concisely as: One step
beyond Mc/I and T/2Ain thesimplest mannerpossible. The elemen-
tary theories continue to be the foundationof stress analysis, but correc-
tions are often required even for simple box beams, and major additions
to the theory are necessary to deal, far instance, with stresses around
cutouts. General progress in design refinement, the use of less ductile
materials, and the emergence of fatigue as a design criterion are con-
tributing to an ever-increasing need for more accurate stress calculations.
The scopeis confined to thecalculationof the (“applied”) stresses that
result from a givenload; the calculation of the (‘‘allowable”) stresses that
cause failure is not discussed, with one major exception (diagonal ten-
sion). Thetwo fields have grown to such anextentthatit is no longer
feasible to combine them. Moreover, as methods become more refined,
the twofields tend to separate more clearly than they did formerly. (It
would be highly desirable to recognize this separation byrestricting the
term “‘stress analysis” to thefirst field and by using the term “strength
analysis” to denote the typeof calculation more frequently referred to as
stress analysis. This explicit distinction between stress analysis and
strength analysis should help to avoid such errors as using moments of
inertia computed for ultimate-load conditions in the calculation of
dynamic modes.)
Simplicity of method is highly desirable because the valueof any caleu-
lation decreases sharply if it is not completed before the designis frozen.
In the quest for maximum simplicity, the device of working with simpli-
fied conceptual “models,” or phantoms, of the structure has in some
cases been carried to unconventional lengths in this book. Empirical
relations have been employed freely. Finally, the stresses are divided,
when feasible, into an elementary system and a correction, or perturba-
tion, system. The elementary stresses can be dealt with efficiently by
vii