What stress to use for fatigue analysis

Click For Summary
SUMMARY

The discussion focuses on selecting appropriate stress values for fatigue analysis using finite element analysis (FEA) tools. Participants recommend using Von Mises stress for ductile materials under combined loading conditions, while principal stresses are suggested for other scenarios. The confusion arises regarding the calculation of stress ranges, specifically whether to use σ11 directly or to subtract σ33 first. The choice of stress analysis method is heavily influenced by the material properties and loading conditions.

PREREQUISITES
  • Understanding of finite element analysis (FEA) principles
  • Knowledge of material properties, specifically ductile and brittle materials
  • Familiarity with stress analysis concepts, including Von Mises and principal stresses
  • Experience with fatigue analysis techniques and S-N curves
NEXT STEPS
  • Research the application of Von Mises stress in fatigue analysis for ductile materials
  • Explore the differences between principal stress and Von Mises stress in various loading conditions
  • Learn about calculating stress ranges in finite element analysis, specifically σ11 and σ33
  • Investigate fatigue analysis methods for brittle materials and composites
USEFUL FOR

Engineers, material scientists, and analysts involved in fatigue analysis and finite element modeling, particularly those working with ductile and brittle materials under various loading conditions.

scootypuffsnr
Messages
13
Reaction score
0
Hi,

I was wondering which stress values from a finite element program to use for fatigue analysis, (von mises, principal, tresca). I was leaning towards principal stresses but then would my stress range be σ11 from load case 1 (LC1) to σ11 of LC2, or would i need to do σ11-σ33 first and then would my stress range be (σ11-σ33) LC1 to (σ11-σ33) for LC2. Sorry I am a bit confused. Thank you
 
Engineering news on Phys.org
It will largely depend on your material for analysis and loading conditions. Ductile materials with combined loading conditions (e.g. shear + tension) will tend to use Von Mises compared to the material's S-N curve. Brittle materials or composites will have very different analysis methods though...
 

Similar threads

How Can We Calculate the Fatigue Life of a Simply-Supported Beam?
  • · Replies 6 ·
Replies
6
Views
3K
Fatigue life hand calculations based on static FEA results
  • · Replies 4 ·
Replies
4
Views
3K
Random Vibration Fatigue Analysis
  • · Replies 4 ·
Replies
4
Views
3K
Fatigue Testing: Calculating ΔK vs da/dN from R & Max Stress
  • · Replies 1 ·
Replies
1
Views
2K
Time History Fatigue Analysis - Ansys Static Structural Quer
  • · Replies 2 ·
Replies
2
Views
3K
Stress Analysis of Lifting Plate With Bail
  • · Replies 1 ·
Replies
1
Views
2K
Von Mises stress Vs Principle stress
  • · Replies 2 ·
Replies
2
Views
19K
Variable Amplitude Fatigue Analysis - Super Confused on how
  • · Replies 1 ·
Replies
1
Views
2K
Mean stress with miner's rule in fatigue analysis
  • · Replies 1 ·
Replies
1
Views
2K
Fatigue of a Rotor: Predicting Life Expectancy with Variable Cyclic Stresses
  • · Replies 2 ·
Replies
2
Views
2K