IIW White Paper

3 Significance of welding and joining

Homogeneous Structure

Strength Over-Matched Welded Structure

Strength Under-Matched Welded Structure

Remote Plasticity at the Base Metal

Confined Plasticity within Weld Zone

Plastic Zone

Figure 3.4 Schematic showing the significance of yield strength mismatch on deformation and fracture behaviour under static loading (Reproduced courtesy of: GKSS, M. Kocak)

In general, cause and development stages of any damage or failure process of welded structures are complex. Various factors may interact at different stages of any damage occurrence. Use of advanced modelling tools and fitness-for-service procedures at the design stages of complex welded structures could ensure structural integrity and safe operation while contributing to the economic fabrication and inspection scheme. Development of Structural Health Monitoring (SHM) systems for welded structures is still a challenge for the designers and plant operators. Furthermore, use of wireless, remote sensors with sufficient reliability to monitor large and complex structures to prevent development of a critical situation at any part of the structure require further research. This offers new opportunities and challenges for structural and other engineering disciplines.

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Through Optimum Use and Innovation of Welding and Joining Technologies

Improving Global Quality of Life