Introduction to Aircraft Structural Analysis (Elsevier Aerospace Engineering)

412 CHAPTER 14 Fatigue determinedasfollows.SubstitutingforthegustexceedanceE(ue)inEq.(14.21)fromEq.(14.17),we obtain Dg=− 1 1000 ...

14.4 Prediction of Aircraft Fatigue Life 413 The gust damage/km at different forward speedsVeis then found using Eq. (14.21) wit ...

414 CHAPTER 14 Fatigue It can be seen from Eq. (14.26) that gust damage increases in proportion toVe5.26so that increasing forwa ...

14.5 Crack Propagation 415 Fig.14.4 Basic modes of crack growth. Fig.14.5 Stress field in the vicinity of a crack. Equation(14.2 ...

416 CHAPTER 14 Fatigue atpointsclosetotheplaneofthecrack, K= Pα (πa) 1 2 (14.31) inwhichPistheload/unitthickness.Equations(14.30 ...

14.5 Crack Propagation 417 (iv)Aplateoffinitewidthwhavingacentralcrackoflength2a,wherea≤0.3w;α=[sec(aπ/w)]^1 /^2. (v) Foraplateo ...

418 CHAPTER 14 Fatigue Fig.14.6 Plane strain plasticity. 14.5.3 Crack Propagation Rates Having obtained values of the stress int ...

14.5 Crack Propagation 419 inwhicha 1 =a+rp,where,forplanestress rp= 1 8 π ( K fy ) 2 (see[Ref.7]) ThecurvesrepresentedbyEq.(14. ...

420 CHAPTER 14 Fatigue The crack length at failure is given by Eq. (14.30) in whichα=1, K=1708N/mm3/2,and S=175N/mm^2 : af= 1708 ...

Problems 421 P.14.2 AmoreaccurateestimateforthesaferangeofstressforthematerialofP.14.1isgivenbythenonlinear formoftheGoodmanpred ...

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CHAPTER 15 Bending of Open and Closed, Thin-Walled Beams................................... InChapter11,wediscussedthevarioustyp ...

424 CHAPTER 15 Bending of Open and Closed, Thin-Walled Beams Fig.15.1 Bending of a rubber eraser. 15.1 SymmetricalBending....... ...

15.1 Symmetrical Bending 425 Fig.15.2 Symmetrical section beams. Fig.15.3 Beam subjected to a pure sagging bending moment. 15.1. ...

426 CHAPTER 15 Bending of Open and Closed, Thin-Walled Beams Fig.15.4 Bending of a symmetrical section beam. Fig.15.5 Length of ...

15.1 Symmetrical Bending 427 sothat εz=− y R (15.1) ThenegativesigninEq.(15.1)indicatesthatfibersintheregionwhereyispositivewill ...

428 CHAPTER 15 Bending of Open and Closed, Thin-Walled Beams eitherendofST,weseethatthemomentresultantabouttheneutralaxisofthest ...

15.1 Symmetrical Bending 429 Fig.15.6 Direct stress distribution in beam of Example 15.1. The cross section of the beam is doubl ...

430 CHAPTER 15 Bending of Open and Closed, Thin-Walled Beams Example 15.2 NowdeterminethedistributionofdirectstressinthebeamofEx ...

15.1 Symmetrical Bending 431 Now Mx=100cos30◦=86.6kNm My=100sin30◦=50.0kNm } (iii) Mxis,inthiscase,apositivebendingmomentproduci ...