The component shown in Fig. 1 looks impressive. However, there are two major issues that make the design very poor from a welding and fatigue performance standpoint.

First, modern engineering practice expects designers to apply sustainability principles when creating components for welding. You may ask, what does sustainability have to do with welding? This component contains an excessive number of welds with very large weld volume. Any design that depends on this amount of welding will score very low in a weld design evaluation because it increases energy use, material consumption and production cost.

Second, components that will operate in fatigue environments should be designed with the minimum weld requirements. Fewer welds reduce the number of potential locations for imperfections, reduce stress concentration points and reduce the long term burden of inspection and quality control. This component fails both expectations by relying heavily on welds across many surfaces.

Despite its attractive appearance, the design performs poorly in terms of sustainability and fatigue resistance.

In fatigue design, every weld matters. Not just in fabrication cost or schedule but in long term structural reliability. The global welding and structural standards are remarkably consistent on one point:

If a component will operate in a fatigue environment, keep the number of welds to an absolute minimum.

Here is what the major standards say.

BS 7608: BS 7608 makes it clear that welded joints always have lower fatigue classes than parent material. This is due to stress concentration at the weld toe, potential imperfections and residual stresses. The standard emphasises that unnecessary welded details should be avoided in fatigue critical design. Fewer welds directly means fewer fatigue initiation sites.

Eurocode 3 EN 1993-1-9

Eurocode 3 instructs designers to avoid unnecessary welded joints, minimise attachments and eliminate abrupt stiffness changes introduced by welding. Continuous members without interruptions always provide better fatigue performance. The code is blunt: minimise welds where fatigue matters.

DNV RP C203 and DNV ST F101

The DNV fatigue rules state that fatigue cracks almost always initiate at weld toes or weld roots. The guidance is explicit that designers should reduce the number of welded details, reduce welded attachments and simplify geometry to reduce stress hotspots. Cutting welds cuts fatigue risk.

AWS D1.1 Commentary

The AWS D1.1 fatigue commentary explains that weld toes and weld roots are natural stress raisers. Weld imperfections such as undercut, porosity and lack of fusion increase fatigue sensitivity. Reducing the number of welded connections in design improves fatigue life and inspection reliability.

ASME Pressure and Piping Codes

The fatigue guidance in ASME VIII and ASME B31.3 notes that welds introduce local stress concentration factors and that unnecessary welds and attachments should be avoided in regions subject to cyclic loading. Every weld removed is one less location requiring future inspection.

API Offshore Standards

API RP 2A and API fatigue assessment guidance highlight that welded tubular joints and attachments are the dominant fatigue concerns in offshore structures. Reducing the quantity of welds reduces fatigue demand, reduces the number of hotspot categories and reduces long term inspection requirements.

The message is simple. Across all major standards, one design principle repeats:

The best weld for fatigue is the weld you do not have to make. Fewer welds mean fewer stress concentration points, fewer potential imperfections and a smaller long term burden of inspection and monitoring.

If you are designing for fatigue, minimise welds. Your structure will last longer, cost less to inspect and perform better through its entire life cycle.

Reference Table

International Standards Supporting Minimisation of Welds in Fatigue Design

Standard	Full Name	What it Supports Regarding Weld Minimisation
BS 7608	Guide to Fatigue Design and Assessment of Steel Products	States that welded joints have significantly lower fatigue classes than parent material and that unnecessary welded details should be avoided to reduce fatigue initiation sites.
EN 1993-1-9 (Eurocode 3)	Eurocode 3 Design of Steel Structures Part 1-9 Fatigue	Instructs designers to avoid unnecessary welded joints and minimise attachments in fatigue loaded structures due to stress concentration effects and stiffness changes caused by welding.
DNV RP C203	Recommended Practice Fatigue Design of Offshore Steel Structures	States that fatigue cracks almost always initiate at weld toes or weld roots and encourages reducing the number of welded details to lower fatigue hotspots.
DNV ST F101	Submarine Pipeline Systems	Identifies welds as the dominant fatigue critical areas in pipeline systems and supports limiting welds and attachments in cyclic loading zones to reduce fatigue sensitivity.
AWS D1.1 Commentary	Structural Welding Code Steel	Notes that weld toes and roots act as inherent stress raisers and that reducing welded connections helps improve fatigue life and reliability.
ASME BPVC Section VIII Division 2	Rules for Construction of Pressure Vessels Part 5 Design by Analysis Requirements	Fatigue section notes that welded joints introduce local stress concentration factors and that unnecessary welds and attachments should be avoided in regions subject to cyclic loading.
ASME B31.3	Process Piping	Commentary highlights that welds and welded attachments contribute to local stress concentration and should be limited where cyclic loads govern design.
API RP 2A	Recommended Practice for Planning, Designing and Constructing Fixed Offshore Platforms	Identifies welded tubular joints and attachments as primary fatigue concerns and supports reducing unnecessary welds to lower fatigue demand and inspection requirements.
API RP 579	Recommended Practice for Fitness for Service	Fatigue assessment guidance explains that welds are common crack initiation points and reducing welds reduces the long term burden of monitoring fatigue damage.