Cast nodes versus welding node

As an alternative to welded tubular joints cast nodes for supporting and foundation structures for offshore wind turbines can be used. The goal in the dimensioning of cast nodes is to minimize stress concentrations due to variable fillets in the transition area of the tubes (see figure below). This is a reduction of the required plate thicknesses compared with welded tubular nodes possible.

However, the production of cast nodes is expensive, has to be chosen so that with the help of comparative calculations from which number of cast nodes, the manufacturing of complex molds is economically sensible.

Addition to the evidence in the ultimate limit state and fatigue resistance usually also thermal analyzes for the casting process are required in order to assess the development of residual stresses during cooling can.  

Cast nodes
Optimization of fillet radii in a cast nodes


The following services can be offered for the design of cast nodes:

  • Load simulations in the ultimate and serviceability limit state
  • Calculation of fatigue loads in time and frequency domain
  • Buckling analyzes 
  • Calculations for welding and bolted connections
  • Local stress and fatigue calculations
  • Concept studies for novel node forms

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SKI Ingenieurges. mbH
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30177 Hannover

Phone: +49 (0) 511 / 261847-0

Consulting Engineers

BWE Expert Advisory Board