Discontinuity regions are structural parts where abrupt changes in geometry occur, or large concentrated loads are applied.

In concrete structures, such regions are the corbels, deep beams, walls with openings and many others. And while the term appears to be linked with them, such regions are also present in steel structures.  Perfect examples are the perforated webs of steel beams that incorporate services, and connections between steel members.

To deal with these regions, modern codes – for both concrete and steel – have dedicated sections, with design rules that are limited to specific cases. However, modern architectural demands and construction methodologies can lead to design variations that are outside the scope of the code provisions.

To overcome these limitations two new methods of design had to be introduced:

• The Compatible Stress Field Method (CSFM) for the design and assessment of discontinuity regions in concrete structures.
• The Component Based Finite Element Method (CBFEM) for the design and assessment of discontinuity regions in steel members.

These two methods share the same principles that also form the basis of their code compliance and effectiveness:

• They both employ non-linear material laws, which are nevertheless based on code defined material parameters.
• They produce the code required results intuitively.
• They provide a clear understanding of the stress flow.
• The designer has full control over the design process.