Shear flow in thin wall members

[fonseh]

in the flange cube, I didn't show the small vert shear stress which exists downward on the left face, and with its accompanying longitudinal stress which lies on the green area.

do you mean they have the stress like this ( blue part) ? just they are not shown in your diagram ?

 

[PhanthomJay]

Vert shear stress blue down on left face and it's complimentary long shear stress blue right on top face. Get rid of the other blue ones. There are 6 faces of cube I showed three, back faces have equal and opposite shear stresses to maintain rotational equilibrium.

 

[fonseh]

Vert shear stress blue down on left face and it's complimentary long shear stress blue right on top face. Get rid of the other blue ones. There are 6 faces of cube I showed three, back faces have equal and opposite shear stresses to maintain rotational equilibrium.

do you mean the shear stress is like this ? why the shear stress is vertical down at the left face ? do you mean there's no vertical shear stress on the right face ? why ?

For the top part of the beam , is the shear stress direction correct ?

 

[PhanthomJay]

do you mean the shear stress is like this ?

yes

why the shear stress is vertical down at the left face ?

the left face is the front face on the xy plane

do you mean there's no vertical shear stress on the right face ? why ?

no vert shear on right face in the yz plane. Vert shear acts in the xy plane only,and it's complimentary long shear acts on top face in xz plane, in blue. In the plane of the cut.

For the top part of the beam , is the shear stress direction correct ?

yes

Remember that tis is a cut of the flange. Horizontal cut in flange for vert shears in blue and vert cut for horiz shears in black.

 

[fonseh]

yes the left face is the front face on the xy planeno vert shear on right face in the yz plane. Vert shear acts in the xy plane only,and it's complimentary long shear acts on top face in xz plane, in blue. In the plane of the cut.
yes

Remember that tis is a cut of the flange. Horizontal cut in flange for vert shears in blue and vert cut for horiz shears in black.

i think your explanation of x , y , z axes is based on this ?

 

[fonseh]

no vert shear on right face in the yz plane. Vert shear acts in the xy plane only,

why there's no vertical shear act on right face in the yz plane ??

 

[PhanthomJay]

i think your explanation of x , y , z axes is based on this ?

Yes

 

[fonseh]

Yes

could you explain why there's no vertical shear act on right face in the yz plane ??

 

[PhanthomJay]

could you explain why there's no vertical shear act on right face in the yz plane ??

Fonseh

These questions are going way beyond 'homework help', but I've been trying to assist since there is no forum here on Civil/Structural Engineering. In the future, you should probably post in the Mechanical Engineering forum for questions related to general understanding that are NOT homework related.

Anyway, applied loading is in the vertical y direction and bending is about the NA in the y direction about the xx axis. For equilibrium of bending and shear stresses, vertical shear in the xy plane exists on the front and back faces of a cubed element , and complimentary longitudinal stresses occur on the top and bot faces in the xz plane. There is nothing going on in the side yz plane faces since there is no bending taking place in the x direction about the yy axis, the beam supports are at either end along the z axis..

 

[fonseh]

whe

Mechanical Engineering forum

re is it ? can you provide the link ?

 

[PhanthomJay]

from the home page, just toggle down to ENGINEERING/Mechanical Engineering. Just be sure that your question is of a general nature and is NOT Homework related.

https://www.physicsforums.com/forums/mechanical-engineering.101/