CAE Simulation & Solutions

Maschinenbau Ingenieurdienstleistungen GmbH

Technical Office for Engineering Services

# Static Strength

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The proof of static strength has to consider the global failure of the structure due to extreme loading conditions, which are expected to act only seldom. Failure can occur under various circumstances such as yielding of essential components, fracture of material and loss of stability, the latter mainly due to compressive stresses in thin walled and/or slender structures well below the yield stress.

The simplest approach to the static proof of strength would be the application of linear Finite Element methods, giving stresses and buckling loads. In this approach the calculated limit load depends on reliable values for the plastic section factors of the structure. Furthermore several often important effects can’t be captured such as large deformations, yielding of complex cross sections, contact, …. .

Often the adequate determination of the limit loads is not possible with linear methods. In the general case, elasto-plastic material behaviour as well as large deformations have to be taken into account.

For static strength assessments the ductility of the material also plays an important role. For brittle materials all notches have to be taken into account in detail, since they could cause material fracture. The 6^{th} edition of the FKM guideline gives a threshold value of 6% for the elongation at break. Materials with more than 6% are ductile. The cast iron GJL is always treated as brittle.

The software LIMIT includes various design codes and guidelines for different types of proof of strength. All previously mentioned assessment types are available: