
WCFA'22VFA
Programme of the Workshop
The course is built in such a way, that no prior knowledge on fatigue analysis is needed. The basic principles
of the common fatigue damage estimation are described in the first day,
while the lectures on vibration fatigue analysis follow in next two days.
In order to better suit the needs of participants and to fit the course to the level of their knowledge,
several variants of the course are provided as shown in the table below.
Topics discussed in individual days follow.
Introduction to Fatigue
This part is covered in variants: Introduction to Fatigue (V1), Complete Course (V3).
Monday, November 14, 2022 
8:008:50 

Registration 
8:509:00 
Jan Papuga 
Welcome info 
9:0010:30 
Milan Růžička 
Basics in Fatigue
Fatigue Curves
Materials Considerations
Loading Considerations
Statistical Aspects 
10:3011:00 

Coffee break 
11:0012:30 
Jan Papuga 
Fatigue Life Estimates
StressLife Based Fatigue Estimate
Factors Affecting Fatigue Life
StrainLife Based Fatigue
An example of the workflow 
12:3013:30 

Lunch 
13:3015:00 
Martin Nesládek 
Fracture Mechanics
FM Approach
Stress Intensity Factor
Fatigue Crack Growth
An example of the workflow 
15:0015:30 

Coffee break 
15:3017:30 
Jan Papuga 
Advanced Topics
Fatigue in Welds
Multiaxial Fatigue
Available Software Applications & Data Sources
FAtigue BEnchmark Repository And Why It Should Matter 
Vibration Fatigue Analysis, Part 1
This part is included in all variants except of Introduction to Fatigue (V1).
Tuesday, November 15, 2022 
8:008:50 

Registration 
8:509:00 
Jan Papuga 
Welcome info 
9:0010:30 
Janko Slavič 
Signal Processing, Part 1
Classifying Time Signals and PSD’s
Statistics, probability and reliability
Loads & “Cross PSD’s”
Gaussian, random and stationary data
Zero and peak crossing rates
Irregularity factor
Root mean square (RMS) value
Moments 
10:3011:00 

Coffee break 
11:0012:30 
Janko Slavič 
Signal Processing, Part 2
System Transfer Functions (Frequency Domain)
Choosing points on the transfer function
How transfer functions work
FFT’s and PSD’s
Buffers and window averaging
Calculating PSD’s From Time Signals
Hand calculations from a PSD
Case Study
Homework 
12:3014:00 

Lunch 
14:0015:30 
Denis Benasciutti 
Uniaxial Vibration Fatigue Analysis, Part 1
Analysis of variable amplitude loadings (cycle counting, damage accumulation, critical damage,...). Example.
Extension to random loadings: amplitude probability distribution, expected damage, fatigue life. Example.
Switching to frequency domain: random processes, different analysis levels (from amplitude distribution to damage)
Recaps of PSD concepts (spectral moments, bandwidth parameters). Types of PSD (narrow band, wide band, bimodal) and relationship with cycle distribution damage. 
15:3016:00 

Coffee break 
16:0017:30 
Denis Benasciutti 
Uniaxial Vibration Fatigue Analysis, Part 2
Overview of spectral methods
 for narrowband and wideband case (narrow band, Wirsching & Light, Dirlik, Steinberg, TovoBenasciutti, α_{0.75}method)
 and bimodal case (singlemoment, JiaoMoan, FuCebon)
Comparison of methods: numerical and experimental results
Calculation example from PSD data
Special cases: NonGaussian and nonstationary loadings
Final notes and recommendations 
19:0022:00(?) 

Informal social meeting 
Vibration Fatigue Analysis, Part 2
This part is included in all variants except of Introduction to Fatigue (V1).
Wednesday, November 16, 2022 
8:009:30 
Filippo Cianetti 
Introduction to Dynamic Analysis
Undamped and damped freeresponse
Harmonic and general forcing excitation
Frequency response function
Base excitation
Homework 
9:3010:00 

Coffee break 
10:0011:30 
Massimiliano Palmieri 
Dynamic Analysis of Randomly Excited Systems
Dynamic analysis by FE
Dynamic analysis by modal approach
How to obtain strain/stress PSD responses and spectral moments
Case Study
Homework 
11:3012:30 

Lunch 
12:3014:00 
Adam Niesłony 
Multiaxial Vibration Fatigue Analysis, Part 1
Understanding multiaxial load and multiaxial stress state
Description of the spatial stress state
Relation between stress state components, nonproportionality
General concept of frequency domain fatigue life assessment in multiaxial stress state 
14:0014:30 

Coffee break 
14:3016:00 
Adam Niesłony 
Multiaxial Vibration Fatigue Analysis, Part 2
Multiaxial fatigue failure criteria:
 von Mises stress and its evaluation in frequency domain
 critical plane concept criteria
Case Study
Homework 
16:0016:10 
Jan Papuga 
Closing the workshop 
Timetables of past volumes
papuga@pragtic.com, last update: December 29, 2022 
EXTERN LINKS:
