Summary for size effects

In summary, size effects on fatigue life can be attributed to a variety of reasons, including stress gradients, macro-yielding, and the statistical distribution of internal defects (that is, a weakest link concept) with an assumed distribution. These are illustrated in the following table:

Concept	Correction factor
Stress gradient
Adjustment for macro-yielding
Weakest-link concept
Neuber's approach to micro-yielding

In the strain-life approach, macroscopic yielding effects are accounted for automatically.

Note:

If you previously created durability models using LMS Virtual.Lab Durability, type the product of the Surface Correction and Size Correction values from that application in the Cumulated Fatigue Correction box for the Fatigue Correction Factor durability simulation object in Specialist Durability. For example, if Surface Correction was set to 1.2 and Size Correction was set to 2 in LMS Virtual.Lab Durability, then the value for Cumulated Fatigue Correction in Specialist Durability would be 2.4.

Learn more

The fatigue notch factor

Examples for size effects

Stress gradients

Theoretical concepts

Application of the theory

Macroscopic yielding

Neuber's approach to micro-yielding

Surface effects

Quick links

Command reference

Pre/Post video examples

Bulk Entry Descriptions

Simcenter 3D tutorials

Browse Simcenter 3D help by product area

Summary for size effects, Simcenter 3D 2021.1 Series

© 2020 Siemens

window.mainLanguage="en_US"

window.delivId=""

window.projectId=""

MathJax.Hub.Config({ TeX: { extensions: ["autoload-all.js"] }, tex2jax: { displayMath: [ ] }, "SVG": { scale: 125 } });