Elasto-plastic viewing the bottom of the notch

Unnotched comparative sample for the simulation of the stress-strain behavior in the notch root
Unnotched comparative sample for the simulation of the stress-strain behavior in the notch root

When notch strain concept (KDK), also referred to as the notch root concept, the local stresses and strains for the critical failure location of the component are calculated on the basis of an elastic-plastic material behavior and compared with the locally tolerable stresses and strains. The beginnings of the notch root concept goes back to LAWRENCE. Later it was prepared in detail by SEEGER. It is applicable to both welded and non-welded constructions of steel. It is assumed that the damage behavior is equivalent to the notch root with the damage behavior of unnotched material sample, the illustration at right.

When notch strain concept must like the notch stress concept, the geometry values and the material condition in fail-critical crack initiation site completely to be writable. In contrast to the notch stress concept, which is based mainly on experimental studies, but tried the notch strain concept to grasp the real stress and failure processes approximate calculation. Only the material parameters based on experiments in uniaxially stressed, un-notched sample of material. It can be set up to technical crack initiation at a given load follow directly the life of components. There is also the possibility to determine computational scribe SN curves for the application of the rated stress, structure stress or notch stress concept. Some applications of the method for steel structures can be found for example in the publication list.

How to notch strain concept

The individual calculation steps in the notch strain concept
The individual calculation steps in the notch strain concept