1. Lecture # 23 & 24
Compound Stress
Objective:-
To find total stress ( and ) from central forces and moment.
Compound normal stress:
Normal stress caused by different faces and moments such as (N, My, Mz)
Compound shear stress:
Shear stresses caused by different forces and moments such as (Vy, Vz, T) y x z N My Mz Vy Vz T
Compound normal stress
Compound shear stress

2. Compound Stress y My N Mz My Vy Vz T Vy
N = Mz Vz x z T
Select + sign wherever moment is causing tension in +ve y or +ve z- axis.

3. Example:
A force of N is applied to the edge of the member. Neglect the weight of
the member and determine the state of stress at point B and C.

4. Solution:

5. Example:
The member has a rectangular cross section. Determine the state of stress
that the loading produces at point C.

6. Solution:
N = kN V = kN M = kN·m

7. Solution (cont.):

8. Example:
The solid rod has a radius of 0.75 cm. If it is subjected to the loading shown,
determine the state of stress at point A.

9. Solution: =

10. Solution (cont.): Internal Loading. = (c) 7000 N·cm 8000 N·cm 500 N

11. Solution (cont.):
Normal Force.
Shear Force.

12. Example: Normal Force. Bending moment.
The rectangular block of negligible weight is subjected to a vertical force of 40 kN, which is applied to its corner. Determine the normal-stress distribution acting on a section through ABCD.
Normal Force.
Bending moment.

13. Solution:

14. Solution (cont.):

15. The enD