這種方法的設(shè)計思路是：假定構(gòu)件中存在著裂紋（依據(jù)無損探傷能力、使用經(jīng)驗等假定其初始尺寸），用斷裂力學(xué)分析、疲勞裂紋擴(kuò)展分析和試驗驗證，證明在定期檢查肯定能發(fā)現(xiàn)之前，裂紋不會擴(kuò)展到足以引起破壞。
斷裂判據(jù)和裂紋擴(kuò)展速率方程是損傷容限設(shè)計的基礎(chǔ)。損傷容限設(shè)計希望在裂紋到達(dá)臨界尺寸ac前檢出裂紋。因此，要選用韌性較好、裂紋擴(kuò)展緩慢的材料，以保證有足夠大的臨界裂紋尺寸ac和充分的時間，安排檢查并及時發(fā)現(xiàn)裂紋。
四、耐久性設(shè)計 (Durability design)
20世紀(jì)80年代起，以經(jīng)濟(jì)壽命控制為目標(biāo)的耐久性設(shè)計概念形成。耐久性是構(gòu)件和結(jié)構(gòu)在規(guī)定的使用條件下抗疲勞斷裂性能的一種定量度量。這種方法首先要定義疲勞破壞嚴(yán)重細(xì)節(jié)（如孔、槽、圓弧、臺階等處）處的初始疲勞質(zhì)量，描繪與材料、設(shè)計、制造質(zhì)量相關(guān)的初始疲勞損傷狀態(tài)，再用疲勞或疲勞裂紋擴(kuò)展分析預(yù)測在不同使用時刻損傷狀態(tài)的變化，確定其經(jīng)濟(jì)壽命，制定使用、維修方案。
結(jié)構(gòu)使用到某一壽命時，發(fā)生了不能經(jīng)濟(jì)修理的廣布損傷，而不修理又可能引起結(jié)構(gòu)的功能問題，這一壽命就稱經(jīng)濟(jì)壽命。
耐久性設(shè)計由原來不考慮裂紋或僅考慮少數(shù)最嚴(yán)重的單個裂紋，發(fā)展到考慮全部可能出現(xiàn)的裂紋群；由僅考慮材料的疲勞抗力，發(fā)展到考慮細(xì)節(jié)設(shè)計及其制造質(zhì)量對疲勞抗力的影響；由僅考慮安全，發(fā)展到綜合考慮安全、功能及使用經(jīng)濟(jì)性；提供指導(dǎo)設(shè)計、制造、使用、維護(hù)的綜合信息。耐久性設(shè)計已經(jīng)開始應(yīng)用于一些飛機(jī)結(jié)構(gòu)及其它重要工程構(gòu)件中，是21世紀(jì)疲勞斷裂控制研究的一個主要發(fā)展方向。
FX3G-24MR/ES-A Box 1745-LP156/C Allen Bradley SLC 150 1745LP156
Allen Bradley Interface Converter 1745-PCC & 1745-C1
Allen Bradley 1745E153 A 1745-E153 /A SLC150 Expansion
Pre Wired Allen Bradley 1745-LP153 1745-E103
New in Box 1745-LP154/C Allen Bradley SLC 150 1745LP154
Allen Bradley 1745-PT1 SER A
New in Box 1745-E154 Allen Bradley SLC 150 1745E154
ALLEN BRADLEY 1745-M1 EEPROM MEMORY MODULE NEW NIB
ALLEN BRADLEY 1745-PT1 USPP 1745PT1
ALLEN BRADLEY 1745-PT1 SERIES A SLC PLC PROGRAMMER
New in Box 1745-LP101/D Allen Bradley 1745LP101 N843
Allen-Bradley 1745-M1 1745M1 ser B New IN BoX
ALLEN BRADLEY 1745-LP101 NSPP 1745LP101
ALLEN BRADLEY 1745-LP101 USPP 1745LP101
Allen-Bradley 1745-LP151 Ser C SLC 150 Programmable Co
ALLEN BRADLEY 1745-C3 NSFP 1745C3
ALLEN BRADLEY 1745-C2 NSFP 1745C2
ALLEN BRADLEY 1745-LP102 USPP 1745LP102
ALLEN BRADLEY 1745-LP145 USPP 1745LP145
ALLEN BRADLEY 1745-C1 USPP 1745C1
ALLEN BRADLEY 1745-E154 USPP 1745E154
NIB ALLEN BRADLEY 1745-M1 MEMORY MODULE 1745M1
ALLEN BRADLEY 1745-B1 NSFP 1745B1
ALLEN BRADLEY 1745-E105 USPP 1745E105
ALLEN BRADLEY 1745-E106 NSPP 1745E106
ALLEN BRADLEY 1745-E103 USPP 1745E103
ALLEN BRADLEY 1745-E151 USPP 1745E151
ALLEN BRADLEY 1745-E153 USPP 1745E153
Allen Bradley 1745-PT1
Allen Bradley 1745-PCC SLC Interface Converter Ser. A
ALLEN BRADLEY 1745-LP151 SLC 150 PLC NIB
ALLEN BRADLEY SLC100 EXPANSION UNIT 1745-E102 SER C
Allen Bradley Cat # 1745-M1 Memory Module *NIB*
ALLEN BRADLEY 1745-PCC INTERFACE CONVERTER W/1745-C1
ALLEN BRADLEY SLC 150 PROGRAMMABLE CONTROLLER 1745-LP15
ALLEN BRADLEY 1745-M1 MEMORY MODULE *NEW*
ALLEN-BRADLEY 1745-C3 SLC Interconnect Cable ! WOW !
ALLEN BRADLEY PROGRAMMABLE CONTROLLER 1745-E151*NEW*
ALLEN-BRADLEY 1745-M1 EEPROM Memory Module ! NEW !
NEW ALLEN BRADLEY 1745-E101 EXPANSION PACK
Allen Bradley #1745-LP151 Processor Unit (U) ABS/9
1745-LP153 Allen Bradley PLC SLC150 Processor
Allen Bradley Memory Module 1745-M1 #21216
Allen Bradley #1745-LP101 I/O Module Fixed (U) ABS/9
New in Box 1745-E156 Allen Bradley SLC 150 1745E156
NEW ALLEN BRADLEY 1745-E105 SERIES C
ALLEN BRADLEY 1745-E151 USED 1745E151
NIB ALLEN BRADLEY 1745-E151
ALLEN BRADLEY 1745-PT1 NSPP 1745PT1
ALLEN BRADLEY 1745-PT1 NSFP 1745PT1
Allen Bradley 1745-E153 Expansion Unit Series A NEW
ALLEN BRADLEY 1745-E156 USPP 1745E156
ALLEN BRADLEY 1745-E157 SLC150 EXPANSION UNIT NEW
Allen Bradley 1745-E105 Relay Expansion Unit (NEW)
ALLEN BRADLEY 1745-M1 NSFP 1745M1
ALLEN BRADLEY 1745-E145 USPP 1745E145
ALLEN BRADLEY 1745-E157 USPP 1745E157
ALLEN BRADLEY 1745-E155 USPP 1745E155
ALLEN BRADLEY 1745-E105 NSFP 1745E105
ALLEN BRADLEY 1745-E106 NSFP 1745E106
ALLEN BRADLEY 1745-E106 USPP 1745E106
ALLEN BRADLEY 1745-E101 NSFP 1745E101
ALLEN BRADLEY 1745-E103 NSFP 1745E103
ALLEN BRADLEY 1745-LP153 USPP 1745LP153
ALLEN BRADLEY 1745-E151 NSPP 1745E151
ALLEN BRADLEY 1745-E151 NSFP 1745E151
Allen Bradley Memory Module 1745-M1 ____L25.1
ALLEN BRADLEY 1745-LP151
ALLEN BRADLEY 1745-LP101 PROGRAMABLE CONTROLLER
Allen Bradley 1745-R1 Relay Board Processor Unit *NIB*
ALLEN BRADLEY 1745-E105
Allen Bradley SLC150 PLC 1745-LP156
Allen Bradley 1745-E101 /B | Expansion Unit *NIB*
Allen Bradley 1745-E106 Analog Input Expansion Unit NIB
Allen Bradley 1745-C1 Processor/Programmer Cable Ref
ALLEN-BRADLEY 1745-M1 EEPROM Memory Module ! WOW !
ALLEN BRADLEY SLC 100 1745-E104 WORKING PULL SER B
Allen Bradley Processor Unit 1745-LP101 1745LP101 Ser D
ALLEN BRADLEY SLC 100 1745-E105 WORKING PULL SER C
New 1745-E152 Allen Bradley SLC 150 1745E152 N839-1
ALLEN BRADLEY SLC 100 1745-E104 WORKING PULL SER B
1745LP101 NEW ALLEN BRADLEY 1745 LP101 FREE SHIPPING
USED ALLEN BRADLEY SLC100 RELAY OUTPUT 1745-E105 C
NEW Allen Bradley 1745-B1 1745B1 FREE SHIPPING NEW
Allen Bradley 1745-P101 1745P10 Programmable Controller
Allen Bradley Battery Assy. M# 1745-B1 ~NIB SURPLUS~
Allen Bradley 1745-M1 EEPROM Memory Module NEW
1745-E103 ALLEN BRADLEY
NEW!!! Allen Bradley 1745-E101 1745E101 Expansion Unit
Allen Bradley SLC 100 Relay Output Expansion 1745-E105
1745-E101 Allen Bradley SLC100 Expansion Unit
Allen Bradley 1745-PCC SER A
Allen Bradley 1745-E151 Series-B SCL150 Expansion Unit
2 NICE ALLEN BRADLEY SLC 100 PROCESSOR UNITS 1745-LP103
ALLEN BRADLEY 1745-E156 NSPP 1745E156
Allen Bradley 1745-C2 SER B
1745-LP154 SERIES C FRN 6 ---- 1 YEAR WARRANTY
ALLEN BRADLEY SLC 150 PROCESSOR 1745-LP151
ALLEN BRADLEY 1745-E104 NSFP 1745E104
ALLEN BRADLEY 1745-R2 NSFP 1745R2
ALLEN BRADLEY 1745-E155 NSPP 1745E155
ALLEN BRADLEY 1745-LP154 NSPP 1745LP154
ALLEN BRADLEY 1745-E105 NSPP 1745E105
ALLEN BRADLEY 1745-E101 NSPP 1745E101
ALLEN BRADLEY 1745-E151 SER.A SLC 150 EXPANION
ALLEN BRADLEY 1745-E153 NSFP 1745E153
NS** ALLEN-BRADLEY 1745-E156 SLC 150 EXPANSION UNIT
ALLEN BRADLEY 1745-LP101 SLC 100 PROCESSOR UNIT
1745-M1 Allen-Bradley EEPROM Module,SLC 100 / 150 NIB
Allen Bradley 1745-LP102 Ser A Programmable Control
1745-E101 SERIES A - NIB - 1 YEAR WARRANTY
ALLEN BRADLEY 1745-LP101 SER D SLC 100 PLC
Allen Bradley SLC 100 I/O Expansion Unit 1745-E101
Unused Allen Bradley Memory Module 1745-M1
ALLEN BRADLEY 1745-LP101 D SLC-100 PLC
ALLEN BRADLEY 1745-LP101 SLC 100 PLC UNIT
Allen Bradley 1745-E101
Allen-Bradley SLC 100 PLC cat 1745-E101
ALLEN BRADLEY SLC 150 EXPANSION UNIT 1745-E151
ALLEN BRADLEY 1745-E101 PROGRAMMABLE CONTROLLER
1745-LP101 Allen Bradley NIB 1745LP101 New
ALLEN BRADLEY 1745-E107 -NEW- 1745E107
ALLEN BRADLEY SLC100 BASIC EXPANSION UNIT #1745-E101
Allen Bradley 1745-E153 PLC Expansion Unit *BNIB*
AB 1745-E151 Series-A SCL150 Expansion Unit
Allen-Bradley SLC100 Replacement Relay Board 1745-R1 !!
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