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Presentation laddar. Vänta.

Conference Oslo 2007-05-09 1 Eurocode 3 Part 1-5 (EN 1993-1-5) Plated structural elements Professor Bernt Johansson Steel Structures Luleå University of.

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En presentation över ämnet: "Conference Oslo 2007-05-09 1 Eurocode 3 Part 1-5 (EN 1993-1-5) Plated structural elements Professor Bernt Johansson Steel Structures Luleå University of."— Presentationens avskrift:

1 Conference Oslo Eurocode 3 Part 1-5 (EN ) Plated structural elements Professor Bernt Johansson Steel Structures Luleå University of Technology

2 Conference Oslo Eurocode Introduction 2 Basis of design and modelling 3 Shear lag in member design 4 Plate buckling effects due to direct stress 5 Resistance to shear 6 Resistance to transverse forces 7 Interaction 8 Flange induced buckling 9 Stiffeners and detailing 10 Reduced stress method

3 Conference Oslo Shear lag b eff =  b

4 Conference Oslo Shear lag

5 Conference Oslo

6 6 Shear lag At Ultimate Limit State  * =  

7 Conference Oslo Plate buckling, classical theory of stability x y a b

8 Conference Oslo Post buckling behaviour of plate with initial imperfections  /  cr w t w o t

9 Conference Oslo Influence of boundary conditions a)b)

10 Conference Oslo Effective width, von Karman fyfy b ef /2 b

11 Conference Oslo Test results plate buckling

12 Conference Oslo Residual stresses

13 Conference Oslo Flange buckling

14 Conference Oslo Flange buckling, post buckling behaviour Stress distribution for  m = 2  cr

15 Conference Oslo Test results flange buckling

16 Conference Oslo Effective cross section for centric compression b f,eff bfbf tftf twtw b w, eff / 2 bwbw b w,eff =  b w  = 1,0 if ≤ 0,67 if > 0,67

17 Conference Oslo Effective cross section for centric compression b f,eff bfbf tftf twtw b w, eff / 2 bwbw b f,eff =  b f  = 1,0 om ≤ 0,75 om > 0,75

18 Conference Oslo Cross section classes for bending in EC3

19 Conference Oslo

20 Conference Oslo Web in class 3

21 Conference Oslo Effective cross section for web plate

22 Conference Oslo Plates with longitudinal stiffeners Determine effective area A c,ef,loc for buckling of subpanels Determine reduction factor  for buckling of the stiffened plate Determine reduction factor  c for column like buckling of the stiffened panel Interpolate between  and  c to get final reduction factor  c.

23 Conference Oslo Plates with longitudinal stiffeners  cr,p is the critical stress for plate buckling according to orthotropic plate theory.

24 Conference Oslo Second moment of area of the whole stiffened plate; a b 11 22

25 Conference Oslo One stiffener N cr is the largest of:

26 Conference Oslo Column type buckling Buckling of the stiffened plate with longitudinal edges assumed to be unsupported.

27 Conference Oslo  = 0,34 for closed stiffener  = 0,49 for open stiffener Reduction factor  c

28 Conference Oslo Interpolation and effective area Final effective area

29 Conference Oslo Software EBPlate A software for calculating critical stresses for stiffened or unstiffened plates created by CTICM is available free of charge on the Internet at the URL

30 Conference Oslo Reduktion för belastad area Röd kurva EK Svarta kurvor BKR Reduktion enligt EK avser karakteristisk last och gäller endast för pelare och väggar medan BKR:s reduktion gäller alla konstruktionsdelar och även vanlig last. m2m2

31 Conference Oslo

32 Conference Oslo

33 Conference Oslo

34 Conference Oslo  cr =2,508x300=752 MPa Konventionell beräkning ger  cr =624 MPa

35 Conference Oslo  cr =4,857x300=1457 MPa Avser livets kant, mitt för avstyvningen fås  cr = 728 MPa

36 Conference Oslo Eurokod 2 Del 1-1 Allmänna regler och byggnader Del 1-2 Brand Del 2 Broar Del 3 Behållare och barriärer

37 Conference Oslo Eurokod 3 Allmänna delarTillämpningsdelar Del 1-1 Allmänna regler och byggnader Del 1-2 Brand Del 1-3 Tunnplåtskonstruktioner Del 1-4 Rostfritt stål Del 1-5 Plåtbalkar Del 1-6 Skalkonstruktioner Del 1-7 Transversalbelastad plåt Del 1-8 Förband och knutpunkter Del 1-9 Utmattning Del 1-10 Sprödbrott och skiktbristning Del 1-11 Stålkablar Del 1-12 Utvidgning till S700 Del 2 Broar Del 3-1 Torn och master Del 3-2 Skorstenar Del 4-1Tankar Del 4-2Silos Del 4-3Rörledningar Del 5Pålar och sponter Del 6 Kranbanor  cr = 0,6764x100 = 67,6 MPa Konventionell beräkning ger  cr = 62,8 MPa

38 Conference Oslo Yield resistance to shear 0, G/fvG/fv fv fv   0,82  = 1,2 for grades up to and including S460  = 1 for higher grades

39 Conference Oslo Shear buckling

40 Conference Oslo Resistance to shear buckling

41 Conference Oslo Model for shear buckling resistance

42 Conference Oslo Resistance according to Eurocode 3-1-5

43 Conference Oslo Rigid end post The bearing stiffener should be designed for the support reaction. The additional stiffener should fulfil

44 Conference Oslo Contribution from flanges

45 Conference Oslo Patch loading

46 Conference Oslo Stress distribution under concentrated load

47 Conference Oslo Critical force

48 Conference Oslo Yield force

49 Conference Oslo Resistance to patch load

50 Conference Oslo Interaction If two or more cross sectional resultants act simultaneously they interact in using the resistance. Often the interaction is weak and it is neglected.

51 Conference Oslo Bending and shear yy h fyfy fyfy According to Eurocode for an I-girder

52 Conference Oslo Interaction M-V

53 Conference Oslo Interaction patch load and bending

54 Conference Oslo Flange induced buckling K=0,55 elastic resistance K=0,40 plastic resistance K=0,30 plastic rotation


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