How to use masonry wall material & shear diagram

[structech08]

Dear ETABS USER,

1. How do we define concrete masonry unit (cmu) in ETABS?
2. What are the parameters to change in ETABS to use cmu instead of RC Wall?
3. Why is it that the shear diagram of uniformly distributed load in a beam has trapezoidal diagram instead of triangular? I use shell element and meshed it with four nodes, but I found the diagram trapezoidal instead of triangle diagram shear.

Thank you for your valuable info.

structech 08

 

[zeemas]

1. If you want to use CMU just for putting load then i will suggest to calclulate CMU weight per foot and used as a line load. Otherwise it will add stiffness to your analysis.
2. For using CMU as a shear wall, i think i will treat as same for analysis purpose, but with reduced thickness and reduced weight.
3. I am not sure what actually you are doing with shell meshing, because what i understand that trapezoidal shape will be because of that. Try to check with a simple beam you might get the answer.

best!!
Z

 

[structech08]

Dear Zeemas,

Thank you for your info.

Regarding CMU, it will be used to resist the lateral force as as if it is RC shear wall.

Re shear diagram, I meshed the slab (4x4) supported by beam to have proper distribution of line load but it seems the nodes in the mesh act as support to the slab instead of the beam supporting the slab.

Regards,
structech 08

 

[seny]

to use cmu instead of concrete, just define material w/ cmu properties (e & weight ) and assign this material to your shell element(membrane if you use for wall, what i do not recommend to do). after analysis you will be able to get wall forces and manually design cmu shear walls.
cmu design is expected in the next etabs version.

 

[structech08]

Hi Seny,

Thank u for your information.

Regards,

structech08