Table Of ContentAFFDL-TR-79-3021
USAF DAMAGE TOLERANT DESIGN HANDBOOK: GUIDELINES FOR THE ANALYSIS AND
DESIGN OF DAMAGE TOLERANT AIRCRAFT
- *
Howard A. Wood and Robert M. Engle Jr.
Structural Integrity Branch
Structures and Dynamics Division
6 DEC !?179
AD A 078,216
Sr rch 1979
TECHNICAL REPORT AFFDL-TR-79-3021
Interim Report for Period January 1977 to November 1978
Approved for public release; distribution unlimited.
iRCE FLIGHT DYNAMICS LABORATORY
)RCE WRIGHT AERONAUTICAL LABORATORIES
A LiORCE SYSTEMS COMMOAND
WRIGhT-PATTERSON AIR FORCE DASE, OHIO 45433
.
0
:
001'
NOTICE
When Government drawings, specifications, or other data are used for any pur-
pose other than in connection with a definitely related Government procurement
operation, the United States Government thereby incurs no responsibility nor any
obligation whatsoever; and the fact that the government may have formulated,
furnished, or in any way supplied the said drawings, specifications, or other
data, is not to be regarded by implication or otherwise as in any manner licen-
sing the holder or any other person or corporation, or conveying any rights or
permission to manufacture, use, or sell any patented invention that may in any
way be related thereto.
This report has been reviewed by the Information Office (O) and is releasable
to the National Technical Information Service (NTIS). At NTIS, it will be avail-
able to the general public, including foreign nations.
This technical report has been reviewed and is approved for publication.
Howald'A. Wood, Principal Scientist Engle
Strbctural Integrity Branch Project Engineer
FOR THE COMMANDER
RALPH L. KUSTER, JR., Col,CSAF Davey L. Smith. Chief
Chief, Structures & Dynamics Division Structural Integrity Branch
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REPORT DOCUMENTATION PAGE
REAm CMSTRUCINoNs
I~i(cid:127)R'P(cid:127)mt b(cid:127)~r (cid:127) 12 GVTACCESSION N.RaR COMPLE'rING~ FORM
PITht~~nTTGOVFA~r~IBNNO EC'"FIT~f'trT" CATALOG NUMBER
AFFDL-TR-79- 2l1,ALA
S.
: .. .... --------- _ .--- . . . . .. " : _ F Evo, .r, J r lq IRIOD COVERE0
J Damage Tolerant Desigr Handbook: Guidelines Interimn ept.o
for the Analysis and Desigr of Damage Tolerant Janl 77-% NovY 78 pI
t Aicrajft Structures, J,/,, f-
C7, AUTHOR'IIIJ CONIRACT OA GRANT NUMBER(.)
ow a A.W Robert M. Engle, Jr,
9. PER;ORMING ORGANIZATION NAME ANO AOORESS to PP AM EL ENT. PROJECT, TASK
Air Force Flight Dynamics Laboratory (AFFDL/FBE) ProAjPeEýcA t : To 24(cid:127)1 UMBERS
Wright-Patterson AFB, OH 45433 Task: 0
l Work Unit: 09
1 1. CONTROLLIN2G OFFICE NAME ANO ADDRESSI
Air Force Flight Dynamics Laboratory (AFFDL/4 .I I Marlý_79. -
Wright-PattersonS ~A3FB3,0 Ohio 45433 30AE
14 MONITORING AGENCY NAME 6 AODRESS(if different Item Cont.oilins Office) 15 SECURITY CLASS. (of flu. r.po,I)
UNCLASSIFIED
'IFI. OECLASSICATION, cO*NGRAOING
16. DISTRIBUTION STATEMENT (of thi. Repor,)
Approved for public release; distribution unlimit d.
7I. DISTRIBUTION STATEMEN' (of the ob.Ircfi eniered in Block I-i tem A rp-,
I1. SUPPLEMENTARY NOTES
19. KEY WORDS (Continue on ,.e010P Sid. It n.ceeol¶ end identify by block nouber)
Damage Tolerance Requirer(cid:127)ents Damage Size Considerations
Fracture Mechanics Damage Tolerance Testing
Residual Strength Fracture Control Guidelines
Crack Growth Predictions Individual Airplane Tracking (-.
Design Guidelines
20 ABSTRACT (Con(Inu* on ro.er. e olde It t.ce..*'y end identify by block nunmber)
/.This is the first edition of a handbook to support the USAF Airplane Damage
Tolerance Requirements contained in MIL-A-83444. The 1handboolprovides
specific background data and justification for the detailed requirements
of MIL-A-83444 and provides guidelines and state-of-the-art analysis methods
to assist contractor and USAF perzonnel in complying with the intent of the
specification and in solving cracking problems, in general, for metallic
aircraft structures. The material --oa.4-sfed/in this document is general
DD , 14 73V EDIoTIoN O I NOV(cid:127)S, 1,9O SOLETE UNCLASSIFIED
SECURITY CLASSIFICATION OF THIS PAGE ("oen Dole Ente(cid:127)od)
Ik
UNCLASS IFI ED
i(cid:127)-;u.T" C7 A77' " IC .TION OF THIS PAGCE(Wh,. D0t. Ent.o.d)
20 AB TRACT (cont'd)
5;rough to be useful in the evaluation of the damage tolerance of in-service
aircraft designed and qualified prior to the issuance of MIL-A-83444. The
.- a(cid:127)C (cid:127)'LoR*t-6 'structured to provide a clear and concise summary of the
specification, MIL-A-83444, as well as supporting analysis methods, test
techniqu"s, And nondestructive inspection (NDI) methods are provided as
state-of-the-art along with suggested and/or recommended practices, limitations,
etc. -F"i--the-conve th--b goopf ies of appropriate USAF structural
specifications are contained as an appV-dix to this handbook.
7)
V
NTIS C~vA/LI
_1
X _T A
UNCLASSIFIED
SECURI~y CLASSIVICATIO04 OF THI.S 'A(.r(Ia7.n .. PI.d
USAF
DAMAGE TOLERANT
DESIGN HANDBOOK
Guidelines
for the
Analysis and Design
of
Damage Tolerant Aircraft
I!
FOREWORD
This report was prepared by Howard A. Wood and Robert M. Engle Jr.
of the Structural Integrity Branch, Structures and Dynamics Division,
Air Force Flight Dynamics Laboratory. The work was performed in-house
under Work Unit 24010109, "Life Analysis and Design Methods for Aero-
space Structures."
Major portions of Chapter 4, "Determination of Residual Strength"
and Chapter 5, "Analysis of Damage Accumulation" were developed
Battelle Memorial Institute, Columbus, Ohio under Contract F33615-75-
C-3101. The principal authors for Battelle were D. Broek and
S. H. Smith. The contract was administered by R. M Engle Jr., Project
Engineer, AFFDL/FBE.
This report covers work accomplished during the period January 1977
throish Septeomber 1978r. f
This report was released for publication in January 1979.
4
iii
COMMENT FORM
TITLE: USAF Damage Tolerant Design Handbook: Guidelines for the
Analysis and Design of Damage lolerant Aircraft Structures
PUBLICATION: AFFDL-TR-79-3021 REVISION: A (Initial Release)
1. USAF solicits your comments concerning this handbook so that its
usefulness may be improved in later editions. Send any comments to
the following address:
AFFOL/FBEC
ATTN: R.M. Engle, Jr.
WPAFB, OH 45433
2. Comments are solicited in the following areas:
a. Is the handbook adequate?
b. What improvements would make the handbook more adequate?
c. Are there any general comments concerning the handbook?
Please note any specific errors which have been discovered.
Include the page number for reference.
4. Revision B of the handbook is already underway so early submission
of any comments would be greatly appeciated.
V
a
REVISICI nf(cid:127) OlC
:EVSTOt'H P T
INITIAL RELEASEE(__,JJL 70)
vii
TABLE OF CONTENTS
CHAPTER
1.0 INTRODUCTION
2.0 SUMARY OF REQUIREMENTS
3.0 DAMAGE SIZE CONSIDERATIONS
4.0 DETERMINATION OF RESIDUAL STRENGTH
5.0 ANALYSIS OF DAMAGE GROWTH
6.0 DAMAGE TOLERANCE ANALYSIS - S.AMPLE PROBLEMS
7.0 DAMAGE TOLERANCE TESTING
8.0 INDIVIDUAL AIRPLANE TRACKING
S
9.0 FRACTURE CONTROL GUIDELINES
10.0 DESIGN GUIDELINES
11.0 REPAIR GUIDELINES
3
APPENDIX: SPECIFICATIONS & STANDARDS
i MIL-STD-1530
ii MIL-SPEC-83444
iii MIL-SPEC-8866
iv MIL-SPEC-8867
ixl
tT
CHAPTER 1
* INTRODUCTION
