DNV OS-C101-LRFD Weld Strength (2011)

An offshore standard DNV OS-C101-LRFD Weld Strength (2011) verifies structural stability for each structural member (weld). Weld connections (section 9) is implemented.

https://rules.dnvgl.com/docs/pdf/DNV/codes/docs/2011-04/Os-C101.pdf

To add the standard execute Standard - DNV - DNV OS-C101-LRFD Weld Strength (2011) from the main menu. Alternatively, use the Standard context menu:

By default, all welds that match following criteria are included into selection but can be changed by pressing .

Weld is included in calculations if it is:

1. Straight with the tolerance of 3 degrees;

2. Double-symmetric - weld is formed by 2 planes that are perpendicular to each other with the tolerance of 5 degrees;

Preview weld elements that are not verified press .

Preview selected weld elements by pressing .

If welds are not recognized press to run the Weld Finder tool.

Note: In results only welded parts are calculated. The rest of the parts will not contain results.

Press to set a Correlation factor (Beta_w):

Beta_w factor is obtained from Table C4, section 9 and depends on the material type:

If Include geometrical check option is ON, an extra check with the minimum/maximum weld length and throat thickness will be added to the standard:

Press to set formulas for the check:

It is possible to select 3 predefined types of bounds and custom:

• Eurocode 3 - EN 1993-1-8, chapter 4.5.1 (2) and 4.5.2 (2);
• AISC - ANSI/AISC 360-10, Table J2.4;
• AWS - AWS D1.1:2010, chapters 2.4.2.1, 2.4.2.3, 2.5.4, table 5.8;
• Custom - define all bounds manually. Tip for formulas is shown below:

Remove 'Tip:' and set an 'input value in model units' to make the formula correct.

Result check will contain all included parameters and overall parameter that defines if all bounds pass:

LimitsOK parameter returns 0 if all limits are OK and 12345678 otherwise.

Use Yield/Tensile from - option which defines the Yield Stress/Tensile Strength to use in calculations (from Element/Material or from Weld Finder). By default minimum value of Yield Stress/Tensile Strength is calculated using all weld elements, user can override them in Weld Finder.

Gamma_Mw - material factor that is used for DNV OS C 101 calculations can be found in Table C1, section 9 of the standard:

Gamma_M - material resistance factor for plated structures is a constant value (=1.15) and used in calculations to check base material strength.

Formulas use Yield Stress and Tensile Strength from materials. It is important to set these values for each material. The amount of materials with zero values are displayed:

If count > 0 then press to edit parameters:

Checks are created automatically and divided into few parts:

• Dimensions checks. Geometrical parameters weld area, elastic section modulus, etc.
• Stress checks. Total weld throat stresses at the start and at the end of the weld. Weld Force Summation Tool is used to get summarized grid point forces at the weld nodes.

T|| = shear design stress (in the plane of the throat) parallel to the axis of the weld (equal to X direction in the check);

σ⊥= normal design stress perpendicular to the throat (equal to Y direction of the check);

T⊥ = shear design stress (in the plane of the throat) perpendicular to the axis of the weld (equal to XY direction of the check);

Example of the check for point T1:

• Utilization factors. Total utilization factors, base material check and overall utilization factor checks.

Calculation Method defines the way of results calculations/presentation - per weld part or per element. They are described in Force Summation tool.