Seminar

Methods of fatigue analysis of machine components and structures accounting for the uncertainty of input data are the main subject of the course. The methods include brief description of the three most popular approaches to fatigue life predictions namely: the nominal stress approach (the S-N method), the local strain-life approach (the e-N method) and the fracture mechanics based analysis (the da/dN-DK method).
The scatter of fatigue life of structural components observed in service requires probabilistic approach to fatigue life assessment, where the predicted fatigue life could be associated with the reliability R or the probability of failure Pf. The life-probability relationship can be numerically determined by accounting for the scatter of all input data.
Several realistic example of simulated fatigue life data sets are to be discussed from the point of view of the effect of the character of the scatter of particular input parameters in the S-N, e-N and da/dN-DK method on the reliability and the scatter of predicted fatigue lives. Such an analysis makes it possible to assess the importance of the scatter and accuracy of each parameter of the input data set and to associate reliability with required fatigue life of the object being designed.

Fatigue durability of structural components depends on geometrical features of structural components, material fatigue properties, and service loading. The three basic factors affect the scatter of the predicted and the actual durability of machine components and structures. In order to estimate the scatter of the predicted fatigue durability it is necessary to describe, in a consistent way, the variability of the input data, i.e. the scatter of the geometrical parameters influencing the stress concentration factor, the stress distribution in critical regions, the scatter of the material properties, and the scatter of load scaling parameters.
A wide range of experimental data concerning the scatter of the weld geometrical parameters, material properties and loads will be presented as well.

In addition the frequency domain load spectra and the spectral fatigue are to be discussed including procedures for extraction of rainflow counted stress cycles form the power spectrum density data and fatigue damage analysis.

Presenter

Dr. Grzegorz Glinka - Mechanical and Mechatronics Engineering Professor - Univeristy of Waterloo

Dr. Glinka has been with the University of Waterloo since 1989. He has also lectured at the University of Metz, France and at the University College London, England. He holds a PhD and DSc from the Warsaw University of Technology. Dr. Glinka is a specialist in fracture and fatigue of steel structures. As well, he has acted as a United Nations expert. His research interests include fracture of materials, fatigue of structures, multiaxial fatigue and creep of engineering materials, computer aided design, and FEM-elastic-plastic stress-strain analysis. Dr. Glinka has published over 100 articles in technical journals and textbooks.

What Previous Participants have said about this Presenter:

• "The instructor was excellent. He was well prepared, relaxed,...fully capable of answering all questions."
• "Very clear presentation and he was very knowledgeable."
• "I appreciated his practical approach to subject matter. All information was valuable."

APEGBC is an AIBC/CES registered provider offering an AIBC-Accredited activity for 6.5 Non-Core Learning Units.