Determine the critical crack length for a through crack contained within a thick plate of 7150-T651 aluminum alloy that is in uniaxial tension. For this alloy Kic = 24.1 MPa m1/2 and =363 MPa. Assume Y = . The answer should be in mm with 3 decimals of accuracy.

Explanation:

Formula to determine the critical crack is as follows.

  = 1,     = 24.1

  [/tex]\sigma_{y}[/tex] = 570

and,  

                       = 427.5

Hence, we will calculate the critical crack length as follows.

      a =

        =

       =

Therefore, largest size is as follows.

            Largest size = 2a

                                 =

                                 =

Thus, we can conclude that the critical crack length for a through crack contained within the given plate is .

force is mass*acceleration.

we have a very small mass: 11.4*0.001 kg

if we want 0.035n of force, we need an acceleration:

0.035 = 11.4*0.001*a

a = 0.035/(11.4*0.001) m/s^2