Plate Results - Shear Near Top Edge - Elastic Model
Plate Results - Shear Near Top Edge - Elastic Model
(OP)
I'm getting unusual out-of-plane shear results for a simple plate model.
Model Description:
1) Program = RISA (linear elastic)
2) 30ft x 30ft x 2ft thick
3) Elements are 2ft thick (out of plane) x 1ft wide x 1 ft tall
4) top edge is pinned out of plane only, free otherwise
5) sides and bottom edge are fixed
6) loading is triangular, based on fluid: 0ksf at top, 2.73ksf at base
7) E (modulus) based on f'c = 4ksi
Problem:
a) Horizontal shear Qx along top edge is very high
b) The rest of the model results agree with solid mechanics theory, except the top.
c) Top reactions agree with theory.
d) Vertical shear Qy agrees with theory.
e) Attachment: pdf plots of Qx, Qy, Mx, My
So here's the question: Is there a good theoretical explanation why the out-of-plane shear along the top edge (i.e. beam action horizontally) is so high, or is this a modeling error?
[I have a similar post under RISA forum, but this is more of a FEM problem].
Model Description:
1) Program = RISA (linear elastic)
2) 30ft x 30ft x 2ft thick
3) Elements are 2ft thick (out of plane) x 1ft wide x 1 ft tall
4) top edge is pinned out of plane only, free otherwise
5) sides and bottom edge are fixed
6) loading is triangular, based on fluid: 0ksf at top, 2.73ksf at base
7) E (modulus) based on f'c = 4ksi
Problem:
a) Horizontal shear Qx along top edge is very high
b) The rest of the model results agree with solid mechanics theory, except the top.
c) Top reactions agree with theory.
d) Vertical shear Qy agrees with theory.
e) Attachment: pdf plots of Qx, Qy, Mx, My
So here's the question: Is there a good theoretical explanation why the out-of-plane shear along the top edge (i.e. beam action horizontally) is so high, or is this a modeling error?
[I have a similar post under RISA forum, but this is more of a FEM problem].





RE: Plate Results - Shear Near Top Edge - Elastic Model
RE: Plate Results - Shear Near Top Edge - Elastic Model
Another question in mind, if the top edge is pinned, why My exists along top edge (assume my is bending about x-axis).
RE: Plate Results - Shear Near Top Edge - Elastic Model
RE: Plate Results - Shear Near Top Edge - Elastic Model
RE: Plate Results - Shear Near Top Edge - Elastic Model
You interpretation of the contours is correct. There is no appreciable moment being reported at top edge.
Would it be correct to say that the My moment along top edge is simply thrown into the top slab, which has no problem resisting this shear (which is tension in the plane of the horiz slab)? That is, the result may be statically correct, but the design impact of the wall is null?
RE: Plate Results - Shear Near Top Edge - Elastic Model
RE: Plate Results - Shear Near Top Edge - Elastic Model
RE: Plate Results - Shear Near Top Edge - Elastic Model