DTDHB1
Handbook for Damage Tolerant Design
Organization:
USAF - United States Air Force
Year: 2002
Abstract: Introduction
In the early 1970's, the United States Air Force (USAF) developed a damage tolerance philosophy to help eliminate the type of structural failures and cracking problems that had been encountered on various military aircraft. Air Force review of structural failures had revealed that the safe life philosophy did not protect against designs that were intolerant to defects that could be introduced during manufacturing or during in-service use. From the standpoint of flight safety, it was found prudent to assume that new airframe structures could contain initial damage (e.g. scratches, flaws, burrs, cracks, etc) and that not all cracks would be found during inspections of older airframes. Accordingly, a damage tolerance philosophy was formulated based on the demonstration of structural safety under the assumption that pre-existing damage would be present at critical locations of all structurally significant details. The intent was to ensure that the maximum possible initial damage would not grow to a size that would endanger flight safety during the service life of the aircraft. Damage tolerance was formally adopted by the Air Force as part of the Airplane Structural Integrity Program (ASIP) [MIL-STD-1530, 1972] and was implemented originally through MIL-A-83444, Airplane Damage Tolerance Requirements. The Air Force now implements damage tolerant design through the recommended practices of the Department of Defense Joint Services Specification Guide, JSSG-2006 [1998].
The primary purpose of this handbook document is to provide guidelines and state-of-the-art analysis methods that should aid engineering personnel in complying with the intent of the USAF Airplane Damage Tolerant Guidelines for metallic structures. A secondary purpose is to provide specific background data and justification for the detailed guidelines. The handbook has been structured to provide a clear and concise summary of the Damage Tolerant Requirements and the supporting data and rationale behind the critical assumptions. Where appropriate, analysis methods, test techniques, and NDI methods are provided with suggested and/or recommended practices, limitations, etc. so stated. In the Handbook, pertinent paragraphs of JSSG-2006 will be referenced.
The remaining subsections of Section 1 provide:
a) an historical perspective on the evolution of the Air Force approach to structural integrity;
b) an overview of the Air Force Aircraft Structural Integrity Program as implemented through MIL-HDBK-1530;
c) an overview of USAF damage tolerance design guidelines as specified in the Joint Service Specification Guide (JSSG-2006); and,
d) an overview of sustainment in aging aircraft.
The topics covered in Sections 2 through 11 are given in Table 1.0.1. Relevant sample problems are presented in each Section. Additional sample problems are included in the Sample Problem section of the Handbook. For the convenience of the user, links to the appropriate USAF structural specifications are contained as an Appendix to this handbook. Any conflict or discrepancy in information contained in this handbook and/or the Joint Service Specification Guide is unintentional and in all cases, the governing document is the current version of the Guide.
This new version of the Handbook is presented as a web-based document, allowing easy access for all users from any location. The web page will allow timely updates as new methodologies emerge and technologies advance. Finding information will be easier with the search capabilities available in electronic documents. Hyperlinks are provided for sub-sections, figures, tables, and references within the handbook, as well as to other related web sites. Links are provided to websites where referenced papers can be found, software can be downloaded, and additional indepth information is provided. Advantages of this are to give the user the most accurate, up-todate information without reprinting the Handbook.
In addition to the web pages, each Section of the Handbook, as well as the Sample Problems, is available as a file in .pdf format, that can be downloaded and printed.
In the early 1970's, the United States Air Force (USAF) developed a damage tolerance philosophy to help eliminate the type of structural failures and cracking problems that had been encountered on various military aircraft. Air Force review of structural failures had revealed that the safe life philosophy did not protect against designs that were intolerant to defects that could be introduced during manufacturing or during in-service use. From the standpoint of flight safety, it was found prudent to assume that new airframe structures could contain initial damage (e.g. scratches, flaws, burrs, cracks, etc) and that not all cracks would be found during inspections of older airframes. Accordingly, a damage tolerance philosophy was formulated based on the demonstration of structural safety under the assumption that pre-existing damage would be present at critical locations of all structurally significant details. The intent was to ensure that the maximum possible initial damage would not grow to a size that would endanger flight safety during the service life of the aircraft. Damage tolerance was formally adopted by the Air Force as part of the Airplane Structural Integrity Program (ASIP) [MIL-STD-1530, 1972] and was implemented originally through MIL-A-83444, Airplane Damage Tolerance Requirements. The Air Force now implements damage tolerant design through the recommended practices of the Department of Defense Joint Services Specification Guide, JSSG-2006 [1998].
The primary purpose of this handbook document is to provide guidelines and state-of-the-art analysis methods that should aid engineering personnel in complying with the intent of the USAF Airplane Damage Tolerant Guidelines for metallic structures. A secondary purpose is to provide specific background data and justification for the detailed guidelines. The handbook has been structured to provide a clear and concise summary of the Damage Tolerant Requirements and the supporting data and rationale behind the critical assumptions. Where appropriate, analysis methods, test techniques, and NDI methods are provided with suggested and/or recommended practices, limitations, etc. so stated. In the Handbook, pertinent paragraphs of JSSG-2006 will be referenced.
The remaining subsections of Section 1 provide:
a) an historical perspective on the evolution of the Air Force approach to structural integrity;
b) an overview of the Air Force Aircraft Structural Integrity Program as implemented through MIL-HDBK-1530;
c) an overview of USAF damage tolerance design guidelines as specified in the Joint Service Specification Guide (JSSG-2006); and,
d) an overview of sustainment in aging aircraft.
The topics covered in Sections 2 through 11 are given in Table 1.0.1. Relevant sample problems are presented in each Section. Additional sample problems are included in the Sample Problem section of the Handbook. For the convenience of the user, links to the appropriate USAF structural specifications are contained as an Appendix to this handbook. Any conflict or discrepancy in information contained in this handbook and/or the Joint Service Specification Guide is unintentional and in all cases, the governing document is the current version of the Guide.
This new version of the Handbook is presented as a web-based document, allowing easy access for all users from any location. The web page will allow timely updates as new methodologies emerge and technologies advance. Finding information will be easier with the search capabilities available in electronic documents. Hyperlinks are provided for sub-sections, figures, tables, and references within the handbook, as well as to other related web sites. Links are provided to websites where referenced papers can be found, software can be downloaded, and additional indepth information is provided. Advantages of this are to give the user the most accurate, up-todate information without reprinting the Handbook.
In addition to the web pages, each Section of the Handbook, as well as the Sample Problems, is available as a file in .pdf format, that can be downloaded and printed.
Collections
:
Show full item record
contributor author | USAF - United States Air Force | |
date accessioned | 2017-09-04T16:29:46Z | |
date available | 2017-09-04T16:29:46Z | |
date copyright | 37601 | |
date issued | 2002 | |
identifier other | UJTSXBAAAAAAAAAA.pdf | |
identifier uri | http://yse.yabesh.ir/std/handle/yse/92994 | |
description abstract | Introduction In the early 1970's, the United States Air Force (USAF) developed a damage tolerance philosophy to help eliminate the type of structural failures and cracking problems that had been encountered on various military aircraft. Air Force review of structural failures had revealed that the safe life philosophy did not protect against designs that were intolerant to defects that could be introduced during manufacturing or during in-service use. From the standpoint of flight safety, it was found prudent to assume that new airframe structures could contain initial damage (e.g. scratches, flaws, burrs, cracks, etc) and that not all cracks would be found during inspections of older airframes. Accordingly, a damage tolerance philosophy was formulated based on the demonstration of structural safety under the assumption that pre-existing damage would be present at critical locations of all structurally significant details. The intent was to ensure that the maximum possible initial damage would not grow to a size that would endanger flight safety during the service life of the aircraft. Damage tolerance was formally adopted by the Air Force as part of the Airplane Structural Integrity Program (ASIP) [MIL-STD-1530, 1972] and was implemented originally through MIL-A-83444, Airplane Damage Tolerance Requirements. The Air Force now implements damage tolerant design through the recommended practices of the Department of Defense Joint Services Specification Guide, JSSG-2006 [1998]. The primary purpose of this handbook document is to provide guidelines and state-of-the-art analysis methods that should aid engineering personnel in complying with the intent of the USAF Airplane Damage Tolerant Guidelines for metallic structures. A secondary purpose is to provide specific background data and justification for the detailed guidelines. The handbook has been structured to provide a clear and concise summary of the Damage Tolerant Requirements and the supporting data and rationale behind the critical assumptions. Where appropriate, analysis methods, test techniques, and NDI methods are provided with suggested and/or recommended practices, limitations, etc. so stated. In the Handbook, pertinent paragraphs of JSSG-2006 will be referenced. The remaining subsections of Section 1 provide: a) an historical perspective on the evolution of the Air Force approach to structural integrity; b) an overview of the Air Force Aircraft Structural Integrity Program as implemented through MIL-HDBK-1530; c) an overview of USAF damage tolerance design guidelines as specified in the Joint Service Specification Guide (JSSG-2006); and, d) an overview of sustainment in aging aircraft. The topics covered in Sections 2 through 11 are given in Table 1.0.1. Relevant sample problems are presented in each Section. Additional sample problems are included in the Sample Problem section of the Handbook. For the convenience of the user, links to the appropriate USAF structural specifications are contained as an Appendix to this handbook. Any conflict or discrepancy in information contained in this handbook and/or the Joint Service Specification Guide is unintentional and in all cases, the governing document is the current version of the Guide. This new version of the Handbook is presented as a web-based document, allowing easy access for all users from any location. The web page will allow timely updates as new methodologies emerge and technologies advance. Finding information will be easier with the search capabilities available in electronic documents. Hyperlinks are provided for sub-sections, figures, tables, and references within the handbook, as well as to other related web sites. Links are provided to websites where referenced papers can be found, software can be downloaded, and additional indepth information is provided. Advantages of this are to give the user the most accurate, up-todate information without reprinting the Handbook. In addition to the web pages, each Section of the Handbook, as well as the Sample Problems, is available as a file in .pdf format, that can be downloaded and printed. | |
language | English | |
title | DTDHB1 | num |
title | Handbook for Damage Tolerant Design | en |
type | standard | |
page | 593 | |
status | Active | |
tree | USAF - United States Air Force:;2002 | |
contenttype | fulltext |