Component Safety

Evaluating cracks relevant to safety

Component safety

 

Safety is of paramount importance for the permanent and economical operation of components and welded structures. In order to protect people and the environment, legislators specify guidelines for pressure equipment (PED) and construction products, among other things. In particular, the prevention of brittle fracture is essential for component safety.

 

In principle, a component is classified as safe if the loads (stresses) that occur are permanently lower than the resistance (strength, toughness) of the material to fracture (loss of integrity).

 

Therefore: stress S < resistance R (equation of limit state)

 

Cracks impair component safety, but are not always necessarily classified as a safety hazard. Failure due to unstable crack propagation only occurs when cracks reach a critical size. This event can be estimated mathematically using fracture mechanics methods. It is also possible to make statements about a further working life.

 

We have over 30 years of experience in the application of fracture mechanics methods for safety analysis according to general standards such as BS 7910 or API572 or the FKM guideline. We also perform calculations in accordance with EN 1993-1-10 Method 2 (Eurocode 3) and EN 13445 or EN 13480, Part 2, Annex B, Method 3 (pressure vessels and pipes). Numerous buildings and welded constructions have been preserved with these methods.

Brittle fracture at T = -100 °C after fatigue cracking.
Forced fracture starting from fatigue crack at room temperature

FAQ

 

Is a component with a crack still safe to operate?

 

How much time remains until a crack becomes critical and leads to collapse?

 

The determined Charpy toughness is lower than the standard requirement. Is the component still safe?

 

What is the toughness requirement for low-temperature applications for new steels or for welded joints?

Selected sample projects on component safety