DNV OS-C101-WSD Weld Strength (2024)

Standard implemented according to DNV-OS-C101, Offshore Standards - Structural design of offshore units, July 2024 based on the following part of the standard Chapter 2, Section 5, Weld and bolt connections

To add the standard execute Standards - Main - DNV - DNV OS-C101-WSD Weld Strength (2024) from the ribbon:

Common options are described in the Weld Strength Settings chapter.

Press to Set Standard Custom Settings

Press to set a Correlation factor (Beta_w):

Beta_w factor is obtained from Ch. 2, Sec. 5, Table 4 and depends on the material type:

Structural Member - Liquid cargo tanks and water ballast tanks or Elsewhere. Defines the value of minimum leg length as per Ch. 2, Sec 5, Table 2:

Note: if minimum weld leg length is less than defined, utilization factors will display a 12345678 value.

Include Eccentricity — If is checked, an additional bending moment at the weld throat will be taken into account for single fillet weld calculations. The bending moment may appear due to a local eccentricity between the tensile force perpendicular to the longitudinal axis of the weld and that axis.

Note: Include Eccentricity affect only single fillet welds.

Eta_0w_a, Eta_0w_b - basic safety factors for direct weld calculation for equations a) and b) of Ch. 2, Sec. 5.3.8.2. Factors are described in Ch. 2, Sec. 5, Table 5:

Gamma_M - material resistance factor for plated structures is a constant value (=1.15) and used in calculations to check base material strength. Part 1, Section 2 of Recommended Practice DNV–RP-C201.

Standard uses material data (Yield/Tensile) in calculations. Wizard checks if the values are defined for all materials.

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 Stresses are calculated using the weld dimensions at four points at the weld ends;
• Utilization factors. Total utilization factors, base material check and overall utilization factor checks.

Permissible stresses for welds are calculated as described in a standard (using the Tensile Strength) and compared to the Von Mises stress. These are formulas of Check 13.

Permissible stress for the material is calculated using the yield of the material (Check 14). But then the Von Mises stress is calculated assuming weld angle is 0° (even for fillets where angle = 45°) and resistance using weld throat = weld leg length (z). In this case the stresses are calculated not in the weld face, but in weld coordinate system.