Lecture Notes

Problem Statement

Should cover function, constraint and objective

material property: material property does not depend on its size / shape (intensive property)

extensive property: property that changes as size / shape changes

Plastic deformation: non-reversible, occurs when the stress exceeds yield strength

How to Measure Yield Strength

Name	Symbol	Unit
stress	$\sigma$	$MPa$
yield strength	$\sigma_y$	$MPa$
strain	$\epsilon$	-
Yong's modulus	$E$	$GPa$
cross-sectional area	$A$	$mm^2$
percentage of cold work	$\%CW$	-

Equation	Explain
$\sigma=E\epsilon$
$\sigma =\frac{F}{A}$	$F$: force ($N$)
$\epsilon=\frac{L_f-L_i}{L_i}$	$L$: length
$\%CW=\frac{t_i-t_f}{t_i}$	$t$: thickness

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Last update: November 6, 2021
Created: September 30, 2021