Programa de Pós-Graduação em Engenharia Civilil PGECIV - Mestrado Acadêmico Faculdade de Engenharia FEN/UERJ Disciplina: Tópicos Especiais em

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1 Ligações Tubulares EC3 Programa de Pós-Graduação em Engenharia Civilil PGECIV - Mestrado Acadêmico Faculdade de Engenharia FEN/UERJ Disciplina: Tópicos Especiais em Estruturas (Chapa Dobrada) Professor: Luciano Rodrigues Ornelas de Lima 1. Generalities Perfis tubulares são largamente utilizados na Europa, Sudeste Asiático, EUA e na Austrália Países como Canadá, Inglaterra, Alemanha e Holanda fazem uso intensivo de estruturas tubulares e contam com uma produção corrente, industrializada e contínua com alto grau de desenvolvimento tecnológico A situação do mercado brasileiro, no entanto, começa a se alterar em razão da oferta de perfis tubulares estruturais (Vallourec & Mannesmann) Frente a esta nova tecnologia, impõe-se a necessidade de divulgação e implementação do uso desse tipo de perfil em projetos de arquitetura e engenharia, e incrementar o número de trabalhos de pesquisa nesta área 1

2 1. Generalities 1. Generalities Ligação soldada de perfis tubulares carga de ruína da face do perfil flexão, cisalhamento, punção e efeito de membrana As normas de projeto de ligações de perfis tubulares em aço são normalmente baseadas em: análise plástica (formação de linhas de ruptura charneiras plásticas) b elevado (P irreal) critérios de deformações limites (1, 2*t) ou 0, 3*b 0 acréscimo de resistência efeito de membrana Melhores resultados métodos analíticos análise plástica + punção + fenômenos de instabilidade 2

3 1. Generalities 1. Generalities 3

4 1. Generalities 1. Generalities 4

5 1. Generalities 1. Generalities 5

6 1. Generalities 1. Generalities 6

7 For hot finished hollow sections and cold formed hollow sections: the nominal yield strength < 460 N/mm 2 the nominal yield strength > 355 N/mm 2 design resistances reduced by a factor 0,9 The nominal wall thickness 2,5 mm The nominal wall thickness < 25 mm Campo de Aplicação: The compression elements of the members should satisfy the requirements for Class 1 or Class 2 The angles θ i between the chords and the brace members 30º Campo de Aplicação: In gap type joints, in order to ensure that the clearance is adequate for forming satisfactory t welds, the gap between the brace members should not be less than ( t 1 + t 2 ) 7

8 Campo de Aplicação: In overlap type joints, the overlap should be large enough to ensure that the interconnection ti of the brace members is sufficient i for adequate shear transfer from one brace to the other. In any case the overlap should be at least 25%. Exemplos de Ligações Tubulares 8

9 Exemplos de Ligações Tubulares Modos de Ruína Chord face failure (plastic failure of the chord face) or chord plastification (plastic failure of the chord cross-section); axial loading bending moment 9

10 Modos de Ruína Chord side wall failure (or chord web failure) by yielding, crushing or instability (crippling or buckling of the chord side wall or chord web) under the compression brace member; axial loading bending moment Modos de Ruína Chord shear failure axial loading bending moment 10

11 Modos de Ruína Punching shear failure of a hollow section chord wall (crack initiation leading to rupture of the brace members from the chord member); axial loading bending moment Modos de Ruína Brace failure with reduced effective width (cracking in the welds or in the brace members); axial loading bending moment 11

12 Modos de Ruína Local buckling failure of a brace member or of a hollow section chord member at the joint location. axial loading bending moment Welded joints between CHS members 12

13 Welded joints between CHS members Axial Loading Welded joints between CHS members Axial Loading 13

14 Welded joints between CHS members Axial Loading Welded joints between CHS members Axial Loading 14

15 Welded joints between CHS members Bending Moment Welded joints between CHS members Bending Moment 15

16 Welded joints between CHS members Bending Moment Welded joints between CHS members Special Types 16

17 Welded joints between CHS members Reduction Factors Welded joints between CHS members Reduction Factors 17

18 Welded joints between CHS members Reduction Factors Welded joints CHS or RHS members and RHS chord members 18

19 Welded joints CHS or RHS members and RHS chord members b b 1 0 b 1 t 1 1 b 0 t 0 0 b0 2t 0 Welded joints CHS or RHS members and RHS chord members 19

20 Welded joints CHS or RHS members and RHS chord members Axial loading Welded joints CHS or RHS members and RHS chord members Axial loading 20

21 Welded joints CHS or RHS members and RHS chord members Axial loading Welded joints CHS or RHS members and RHS chord members Axial loading T, X and Y joints between RHS or CHS braces and RHS chords 21

22 Welded joints CHS or RHS members and RHS chord members Axial loading T, X and Y joints between RHS or CHS braces and RHS chords Welded joints CHS or RHS members and RHS chord members Axial loading T, X and Y joints between RHS or CHS braces and RHS chords 22

23 Welded joints CHS or RHS members and RHS chord members Axial loading welde ed K and N joints between RHS or CHS braces a nd RHS chords Welded joints CHS or RHS members and RHS chord members Axial loading T, X and Y joints between RHS or CHS braces and RHS chords 23

24 Welded joints CHS or RHS members and RHS chord members Axial loading T, X and Y joints between RHS or CHS braces and RHS chords Welded joints RHS members and RHS chord members Bending moment 24

25 Welded joints RHS members and RHS chord members Bending moment Welded joints RHS members and RHS chord members Bending moment 25

26 3. Examples RHS members and RHS chord members RHS260x260x8 b b b1 0, 875 0, 85 b 0 (EC3) 3. Examples RHS members and RHS chord members "T" Joint chord: perfil brace: perfil b1 h1 t1 fy teta 1 = 90 º b0 h0 t0 fy Verificações da Norma beta = b1 / b0 = 260 = > 0.85 não OK 300 b0 / t0 = 300 = > 10 OK 8 b1 / t1 = 260 = < 35 OK 8 h1 / t1 = 260 = < 35 OK 8 h0 / b0 = 300 = > 0.5 OK 300 h1 / b1 = 260 = > 0.5 OK 260 c0 / t0 = 284 = > 30,36 OK 8 c1 / t1 = 244 = > 30,36 OK 8 26

27 3. Examples RHS members and RHS chord members N 2 knfy0t 0 2 1Rd /, Rd M5 1 sen sen k n (tração) = 1.00 ; n = 1.00 k n (comp) = N 1,Rd (t) = 1.00 * 275 * ( 8 )^2 * ( ) * sen 90 2 * * RAIZ ( ) sen 90 N 1,Rd (t) = kn N 1,Rd (c) = 0.84 * 275 * ( 8 )^2 * ( ) * sen 90 2 * * RAIZ ( ) sen 90 N 1,Rd (c) = kn Vale ressaltar que N 1,Rd representa a carga a ser aplicada no braço que provoca a plastificação da face da corda. 3. Examples RHS members and RHS chord members 500 carga (kn) = 0, deslocamento (mm) carga (kn) = 0,733 carga (kn) = 0, deslocamento (mm) deslocamento (mm) 27

28 3. Examples RHS members and RHS chord members Carga (kn) x 260 x x 250 x x 220 x x 200 x x 180 x x 160 x x 150 x x 140 x x 130 x x 120 x x 110 x Deslocamento (mm) 3. Examples RHS members and RHS chord members 000 0,00 8,80 y 17,7 26,5 35,4 44,3 53,2 62,0 z x 70,9 79,7 Ligação RHS 300x300x8 com RHS200x200x8 Deslocamentos UY (em mm) 28

29 3. Examples RHS members and RHS chord members -274,8-212,6-150,5-88,4-26,2 35,9 98,0 160,15 222,3 284,4 z y x Ligação RHS 300x300x8 com RHS200x200x8 Tensões na direção X (em MPa) 3. Examples RHS members and RHS chord members -236,4-176,0-115,7-55,3 5,0 65,3 125,7 186,0 246,3 306,7 z y x Ligação RHS 300x300x8 com RHS200x200x8 Tensões na direção Y (em MPa) 29

30 3. Examples RHS members and RHS chord members -86,3-42,2 1,9 46,0 90,1 134,2 178,3 222,3 266,4 310,5 z y x Ligação RHS 300x300x8 com RHS200x200x8 Tensões na direção Z (em MPa) 3. Examples RHS members and RHS chord members 19,2 47,6 76,0 104,4 132,9 161,3 189,7 218,2 246,6 275,0 z y x Ligação RHS 300x300x8 com RHS200x200x8 Tensões de Von Mises (em MPa) 30

31 3. Examples RHS members and RHS chord members EC3 limite - modo de ruína (a) Carga (kn) Examples KT Joint - RHS members and RHS chord members Y Z X For the KT joint, the Eurocode 3 provisions consider these types of joints as a K joint, of a gap or overlap type, depending on the joint geometry. Since 0 37, 5, and the overlap ratio, ov is 19 %, the current joint is again slightly out of the Eurocode rules range of validity that assume 0 35 and ov 25%

32 3. Examples KT Joint - RHS members and RHS chord members 191,8 41,4 64,2 191,8 64,2 LOAD CASE = 1 Loadcase 1 RESULTS FILE = 0 TOP STRESS CONTOURS OF SE 314,7 566,7 0 0, , , , , , , , , , , , , , , Max at Node 44 Min E-02 at Node 5107 Z Y X Y X Z deformed mesh Von Mises (in GPa) 3. Examples KT Joint - RHS members and RHS chord members 300 Tensão po nto mais desfavorável (MPa Maximu um von Mises stress No K S ,5 1 1,5 2 2,5 3 Factor multiplicativo da carga não majorada Total load factor 32

33 3. Examples KT Joint - RHS members and RHS chord members LOAD CASE = 1 Loadcase 1 RESULTS FILE = 0 TOP STRESS CONTOURS OF SX LOAD CASE = 1 Loadcase 1 RESULTS FILE = 0 TOP STRESS CONTOURS OF SZ -0, , , , , , , , , , , , , , , Max at Node 79 Min Y E-01 at Node 4070 X Z -0, , , , , , , , , , , , , , , Max at Node 79 Min Y E-01 at Node 2966 X Z Stresses in direction X (chord axis) Stresses in direction Z (middle brace axis) 3. Examples KT Joint - RHS members and RHS chord members 3,5 3 Displac. Res. node 2008 To otal load factor 2,5 2 1, ,8 191,8 41,4 64,2 64,2 0, ,7 566, Brace axial displacement 33

34 3. Examples KT Joint - RHS members and RHS chord members 191,8 41,4 64, ,8 64, brace failure mechanism 314,7 566,7 To otal load (kn) Displac. Res. node 2008 Eurocode 3 Eurocode 3 overlap=25% Brace axial displacement 3. Examples KT Joint - RHS members and RHS chord members The EC 3 failure load brace failure mechanism, represented by the full horizontal line This force is the resultant axial force in the most loaded brace member (770kN). The application of EC3 is out of its validity range the overlap ratio, is 19% < the minimum of 25% ov The same exercise - minimum EC3 value of ov 25% maximum load of 910kN, represented by the horizontal dotted line maximum load obtained is 841kN 34

35 4. Important References Cao, J.J., Packer, J.A., Young, G.J., Yield line analysis of RHS connections with axial loads, J. Constructional Steel Research, vol. 48, nº 1, pp Eurocode 3, pren , 1.8, Design of steel structures Part 1.8: Design of joints ( final draft ), CEN, European Committee for Standardisation, Brussels. 4. Important References Kosteski, N., Packer, J.A., Puthli, R.S., A finite it element method based yield load determination procedure for hollow structural section connections, J. Constructional Steel Research, vol. 59, nº 4,, pp Vallourec & Mannesmann do Brasil, Catálogo de Produtos: Tubos Estruturais de Seções Circulares, Quadradas e Retangulares, 8 pp. 35

36 4. Important References Neves, L.F. C., Lima, L. R. O. de, Jordão, S. and Silva, J. G. S. da, Structural t Analysis of T and KT Joints of a Steel Truss Structure Using the Finite Element Method. Proceedings of the Tenth International Conference on Civil, Structural and Environmental Engineering Computing, Civil-CompComp Press, Stirling, Scotland, pp