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#1

Can someone explain what is MPa√a exactly? I have never come across this..
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5 years ago
#2
(Original post by GPODT)

Can someone explain what is MPa√a exactly? I have never come across this..
A long time since I covered this:

KIC = critical stress intensity factor for a mode I crack.

It's a measure of the materials resistance to crack growth. i.e. force needed to propagate an existing thin crack opening under normal tensile stress perpendicular to the crack (when KIC = fracture toughness).

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#3
(Original post by uberteknik)
A long time since I covered this:

KIC = critical stress intensity factor for a mode I crack.

It's a measure of the materials resistance to crack growth. i.e. force needed to propagate an existing thin crack opening under normal tensile stress perpendicular to the crack (when KIC = fracture toughness).

Sorry if I wasn't clear enough, what I meant was how did they get the units MPa√m for Kic? The √m has confused me.
0
5 years ago
#4
(Original post by GPODT)
Sorry if I wasn't clear enough, what I meant was how did they get the units MPa√m for Kic? The √m has confused me.
It means square root of metre

So MPa√m has units

MPam½

Mega pascal √metre

This would come from the units in its defining equation.
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5 years ago
#5
(Original post by GPODT)
Sorry if I wasn't clear enough, what I meant was how did they get the units MPa√m for Kic? The √m has confused me.
As Stonebridge pointed out, is the remainder after factoring out from the final equation definition for

It's debatable that this is not a very intuitive form for the units (newtons per root metre cubed). I suspect because engineers are concerned more with application and convenience, a more memorable and intuitive unit factors out the exponent and reduces it to pascals root metre.

i.e. since:

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