Where do the units for fracture energy come from in this equation?

[Denzil]

I am having trouble understanding where the units to fracture energy come from when worked out with the following equation.


2$$\gamma$$$$_{ef}$$=$$\frac{K^{2}_{Ic}}{E}$$

fracture energy = fracture toughness/young modulus
i asked my teacher as this is part of my coursework but he was not able to work it out.

I don't understand how the division of Mpa with Mpa = J/m$$^{2}$$


any insight would be much appreciated

 

[ideasrule]

Fracture toughness has units of Pa*sqrt(m), so its square has units of Pa^2 * m. Divide that by Pa and you get Pa*m, or N/m^2 * m=N/m. Can you now see why the units are equal to J/m^2?