00:02
Hi, in this question, se is given as se, that is the endurance limit stress, is given as 40 kpsi.
00:11
40 kpsi.
00:17
S .y is given as, that is the yield stress, is given as 60 kpsi.
00:26
Sut, that is the ultimate stress is given as 80 kpsi.
00:38
Kpsi and t t u m means shear stress is given as 15 kpsi this is tau m the sigma a is equal to tau a is equal to zero these are the data given we need to find the factor of safety guarding against the static failure also we need to find the factor safety using modified good money equation we need to find factor of safety let the factor of safety be n we will denote it with n first of all let us determine the one -vices stresses for the alternating mean and maximum stresses sigma a dash alternating stresses sigma a dash is equal to sigma a square plus 3 times tau a square now let us plug the given values here and determine sigma a dash is equal to 25 square plus 3 times 0 square on calculation we obtained sigma a dash is equal to 25 kpsi now let us determine sigma m dash sigma m dash will be equal to sigma em square plus three times tau m square now let us plug the given values here and obtain the sigma m dash equal to sigma m is 0 square square plus 3 times tau m is 15 square root is equal to 25 .98 kpsi.
03:10
Now let us determine the maximum stress.
03:16
Sigma max dash is equal to the maximum stress plus.
03:31
3 times tau max square, taw max square under the root.
03:44
Again, this sigma max square can be written as sigma a plus sigma m whole square, plus three times tau a plus tau m fold square.
04:10
Entire thing or under the root.
04:15
Now on let us plug the given values and determine sigma match dash is equal to plus sigma em is 0 square plus 3 times 0 plus 15 square under the root.
04:43
On calculation we obtained sigma x .6.
04:47
Is equal to 36 .06 kpsi...