Theory of Critical Distances TCD Extension v1

Refer to a simplified way to use the TCD (Theory of Critical Distances) approach. Exploit a mesh of specific dimensions to evaluate the stress condition in components which present notches and other stress concentration features (such as cracks, weld beads…)

Download TCD Extension v1 for free from the ANSYS App Store

Overview – Extension Highlights:

  • Mesh Controls: mesh setup for the application of the theory.
  • Failure Condition: failure verification. It displays 1 in case of failure, 0 in case of safety.
  • Margin of Failure: it gives the user a quick idea on how much the critical stress has been exceeded.
  • Safety Factor: it performs the safety factor in relation to the Critical Stress.
  • Materials: .xlsx file containing a database with TCD parameters for fracture and fatigue.
    Help Button: Help file pointing to the file in the Help&Files directory: “TCD_Documentation_Details.pdf”.

View the Extension Tutorial Video

For more details, instructions, how to use the Extension, the recommended workflow, please refer to the overview presentation by CADFEM Ireland, Filippo Vargiu:
Theory of Critical Distances – Using Mesh Controls

David Taylor, The Theory of Critical Distances: a new perspective in fracture mechanics, Elsevier BV, 2007.
F. Vargiu et al., Implementation of the Theory of Critical Distances using mesh control, Theor. Appl. Fract. Mech. (2017) (this paper is provided together with the extension in the Help&Files subdirectory).

For further information, please contact:
CADFEM Ireland Ltd,
Filippo Vargiu & Team
David Taylor,



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