In cyclically loaded structures, what is the maximum size of porosity allowed in complete joint penetration groove weld butt joints that are transverse to computed tensile stress?

In the context of cyclically loaded structures, particularly those involving complete joint penetration groove welds that are subjected to transverse computed tensile stress, it is critical to maintain a high standard of weld quality. Porosity in welds can significantly affect the mechanical properties and fatigue life of the weld, particularly when it is under cyclic loading conditions.

For complete joint penetration groove welds, industry standards set a strict limit on the acceptable amount of porosity. In the case of transverse stress, any size of porosity can act as a stress riser, which not only reduces the effective cross-sectional area of the weld but can also initiate cracks that propagate under cyclic loading. Therefore, the requirement that no porosity is allowed in these types of welds is a strict measure to ensure the integrity and safety of the welded structures.

This requirement reflects the understanding that even small amounts of porosity can lead to failure under repeated loading conditions. Unlike other options suggesting specific sizes of porosity, the stance of none allowed establishes a zero-tolerance approach for porosity, ensuring that the performance and reliability of the weld are not compromised in any way.