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March 2014
LIMIT Best Practice Using DVS1612 Version LIMIT2014
www.cae-sim-sol.com
Documentation
page 2 LIMIT Best Practice Using DVS1612 www.cae-sim-sol.com
Assessment with DVS1612
Stress Type, Nominal Stress
Mesh Size
WELD_GLOBAL
WELD
Setups (Examples)
Checks in Postprocessing
Overview
page 3 LIMIT Best Practice Using DVS1612 www.cae-sim-sol.com
Nominal Stress
Assessment of nominal stress Use OFFSET/ENDINGS in LIMIT/SetupManager
Permissible Stress Values include notch effect of girder (e.g. EC3, DVS, …)
Stress Types, Flange with Gusset
Nominal stress
DVS1612
page 4 LIMIT Best Practice Using DVS1612 www.cae-sim-sol.com
Mesh Size Linear quads with reduced integration or centered output According to DVS1612 : Offset from toe to stress point: 1 x t– 1,5 x t
Element size 2 – 3 times thickness sometimes not conservative strong influence on mesh size
Quads with first or higher order interpolation and corner output e.g. quadrilateral, 8 Nodes (e.g. S8R) Mesh size as fine as necessary to resolve gradients in transverse direction. Conforming with DVS1612: define Offset parameter with 1 x t define Endings parameter with at least 1 x t, better 1.5 x t
little influence on mesh size
Mesh Size
Endings
Offset
page 5 LIMIT Best Practice Using DVS1612 www.cae-sim-sol.com
*WELD_GLOBAL
Global analysis:
Stresses taken directly from FE result on both shell surfaces
Assessment points 5 and 6 active
Critical cutting plane with rotating weld direction notch cases define permissible stresses
Result: largest degree of utilization and critical direction
Notes: Can be very conservative, when large stresses parallel (axial) to weld
Is not conservative, when stresses of shell are much lower then in throat of weld
*WELD_GLOBAL
page 6 LIMIT Best Practice Using DVS1612 www.cae-sim-sol.com
*WELD
Local analysis:
Stresses transformed in weld coordinate system: axial, transverse, shear
Assessment points: 1 to 4 => weld cross section
5 and 6 => shell surface
most accurate way to do the fatigue assessment
*WELD
page 7 LIMIT Best Practice Using DVS1612 www.cae-sim-sol.com
Some examples for different setups
Double fillet weld
Single fillet weld
One side full penetration weld
Full penetration weld
*WELD
page 8 LIMIT Best Practice Using DVS1612 www.cae-sim-sol.com
DVS 1612 Double Fillet Weld (connected sheet)
ROOT: Notch cases depending on loading direction
Axial (parallel to weld): Tab.B-1.3, #1.3.13-#1.3.16 => C- Transverse: Tab.B-1.5, #1.5.13 => F2 Shear: page 6, line H => H
Toe: Notch cases depending on loading direction
Axial (parallel to weld): Tab.B-1.3, #1.3.13-#1.3.16 => C- Transverse: Tab.B-1.5, #1.5.1-#1.5.6 => E5 Shear: page 6, line H => H
page 9 LIMIT Best Practice Using DVS1612 www.cae-sim-sol.com
DVS 1612 Double Fillet Weld (continuous sheet) Base Material: Notch cases
depending on loading direction Axial (parallel to weld): Sec. 4.4.2 => A Transverse: Sec. 4.4.2 => A Shear: Sec. 4.4.2 => H
Toe: Notch cases depending on loading direction
Axial (parallel to weld): Tab.B-1.3, #1.3.13-#1.3.16 => C- Transverse: Tab.B-1.4, #1.4.10-#1.4.13 => E5 Shear: page 6, line H => H
Page 10
Double Fillet Weld
Offset: 1 x Thickness, DVS1612, Sec. 4.3 Endings: Corrects for local stress concentration! Use t or even larger values to capture nominal stress!
inactive
Page 11
Single Fillet Weld
Axial: Tab.B-1.3, #1.3.21-#1.3.24 => E4 Toe: Transverse: Tab.B-1.5, #1.5.1-#1.5.6 => E5 Root: Transverse: Tab.B-1.5, #1.5.14 => F2 Shear: page 6, line H or H- => H
Axial: Tab.B-1.3, #1.3.21-#1.3.24 => E4 Axial at End: Tab.B-4.2, #4.2.5 => F1 Transverse: Tab.B-1.4, #1.4.14 => E6 Shear: page 6, line H => H
Base Material inactive
Page 12
One Side Full Penetration Weld
Axial: Tab.B-1.3, #1.3.7-#1.3.12 => C- Toe: Transverse: Tab.B-1.5, #1.5.1-#1.5.6 => E5 Root: Transverse: Tab.B-1.5, #1.5.7-#1.5.9 => E6- Shear: page 6, line H+ => H+
Axial: Tab.B-1.3, #1.3.7-#1.3.12 => C- Axial at End: Tab.B-4.2, #4.2.5 => F1 Transverse: Tab.B-1.4, #1.4.7-#1.4.9 => E6+ Shear: page 6, line H+ => H+
Base Material inactive
Page 13
Full Penetration Weld
Axial: Tab.B-1.3, #1.3.7-#1.3.12 => C- Toe: Transverse: Tab.B-1.5, #1.5.1-#1.5.6 => E5 Root: Transverse: Tab.B-1.5, #1.5.1-#1.5.6 => E5 Shear: page 6, line H+ => H+
Axial: Tab.B-1.3, #1.3.7-#1.3.12 => C- Axial at End: Tab.B-4.2, #4.2.5 => F1 Transverse: Tab.B-1.4, #1.4.1-#1.4.6 => E5 Shear: page 6, line H+ => H+
Base Material inactive
page 14 LIMIT Best Practice Using DVS1612 www.cae-sim-sol.com
Postprocessing
Checking position of stress extraction points:
LIMIT VIEWER
