# Mechanical Engineering Design Notes

 Design Contents

FUNDAMENTALS
Preliminary Matters
Design Methodology
..brain storming
..evaluation matrix
..QFD
Statistical Considerations
..variability in materials
..variability in dimensions
..preferred sizes
Tolerances
Design Factor
Introduction to Failure
Failure Theories
Application of von Mises
..criterion in 2 D

Stress Concentration
..and notch sensitivity
..combined bending and torsion
..fatigue
..fracture mechanics
Instability - Buckling
..slender columns
..Euler formula
..effective length
..short and intermediate columns
.. theory
..deflection
..stress

 Evaluation of Geometric Stress Concentration Factor Using JavaScript or a Java Applet Plate Subject to Tension With Hole in Centre

Stress Concentration Calculator

Fatigue

This applet determines the theoretical stress concentration factor for a rectangular plate subject to tension (in a horizontal direction in the applet below) with a central hole. The ratio of the hole diameter / plate width should not exceed 0.5.

Enter the plate width and hole radius in mm and click on the 'Calculate' button.

This stress concentration factor is for use with the average stress calculated on the net reduced cross section area, ie:

stress = force / (plate thickness (plate width - hole dia.)). The position of the maximum stress is indicated by the red crosses.

These calculations are based on information contained in "Roark's Formulas for Stress and Strain", 6th Ed. McGraw Hill, 1989 and also "Stress Concentration Factors", by R E Peterson, John Wiley and Sons, 1974. Both these publications contain information relating to a large number of configurations.

David Grieve, Revised: 30th July 2017, 28th January 2010; 3 March 2003; Original: 24th August 2000.