Summary of Lec 14: Residual Stress Measurement-1

In this lecture on residual stress measurement techniques, the speaker outlines the different categories of methods used to predict residual stress. They discuss destructive, semi-destructive, and non-destructive techniques, explaining the strain release principle used to measure residual stress accurately. The speaker details the methodology of destructive techniques such as contour method, slitting method, and block removal/splitting/layering method. They also explain the methodology of semi-destructive techniques like default drilling and center hole drilling. Additionally, the speaker introduces non-destructive techniques like neutron diffraction, synchrotron diffraction, and x-ray diffraction for measuring residual stress based on crystallographic property changes. The speaker provides a detailed explanation of the strain relaxation technique using electric resistance strain gauges to measure residual stress along x and y directions. They also discuss how to calculate maximum stress and principal stress direction using strain gauge data. The speaker emphasizes the importance of adjusting for the negative sign in strain gauge readings to accurately determine the actual residual stress in a material. The lecture concludes with a preview of upcoming topics to be covered in subsequent lectures.

Categories of residual stress measurement techniques

• Destructive
• Semi-destructive
• Non-destructive

Methodology of destructive techniques

• contour method
• slitting method
• block removal/splitting/layering method

Methodology of Semi-destructive techniques

• Default drilling
• Center hole drilling

Methodology of Non-destructive techniques

• Neutron diffraction
• Synchrotron diffraction
• X-ray diffraction

Strain Relaxation Technique

Using electric resistance strain gauges to measure residual stress along x and y directions.

Calculation of Maximum Stress and Principal Stress Direction

Using strain gauge data.

Adjustment for Negative Sign in Strain Gauge Readings

To determine actual residual stress.

Speakers/Sources

• The speaker in the video is delivering a lecture on residual stress measurement techniques.

Notable Quotes

— 03:43 — « In my car, I have ventilation. »

Category

Educational

Video