Understanding fatigue is essential for considering various technical conditions which affect fatigue life and crack growth, such as material surface, residual stress, and environmental influence. Fatigue prediction methods can only be evaluated if all mechanism governing are understood, defined and are interpreted correctly.

SINTEF has a well-equipped laboratory and decades of experience for testing of cyclic material properties. 

• S-N curves - relation between stress and life for typical structural joints.
• Fracture mechanics, fatigue crack propagation - growth rate given by da/dN curves
• Cyclic stabilised material data - simulating local material state using stabilized s - e loop and e - N curve
• Endurance limits - stresses below s E, var.amp. and cracks ‘below’D Kth 

SINTEF has capabilities to predict fatigue life as to all common models according to the chosen design philosophy:

• Fatigue damage summation based on S-N curves and load spectrum simulating local material state using stabilised s -e loop and e -N curves
• Local strain approach 
• Fracture mechanic approach

Applications:

• Fatigue life enhancement of welded aluminium joints through mechanical pre-stressing
• Prediction of fatigue life based on detailed topographic data

Research Manager: Bård W. Tveiten, phone: (+47) 98 23 04 38