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There is no devoted design module for masonry walls available but you can define a panel with corresponding material properties. You can access results in many different ways such as maps or cuts (graphical display) as well as tables (e.g reduced results for panels).
If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.
Artur Kosakowski
There is no devoted design module for masonry walls available but you can define a panel with corresponding material properties. You can access results in many different ways such as maps or cuts (graphical display) as well as tables (e.g reduced results for panels).
If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.
Artur Kosakowski
No, there is not unless you delete the part over the linter (where you have tension) and 'replace' the weight of this part with load applied directly to the lintel.
Artur Kosakowski
No, there is not unless you delete the part over the linter (where you have tension) and 'replace' the weight of this part with load applied directly to the lintel.
Artur Kosakowski
Is this what you mean?
If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.
Artur Kosakowski
Is this what you mean?
If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.
Artur Kosakowski
Dear Artur
Greetings
1. Could you find out if I have defined correctly the brick walls as panels have only (compression stiffness) (transfer the slab load to the foundation) or not?
(Please see the capture)
2. Is correct to use the linear release at the boundary of brick walls to prevent any moment transferring between (slab& columns) and brick walls? If so, how do I overcome the instability message (type 1)?
(Please resend the rtd. File after correction)
3. Also, is correct to use a linear support instead of bar (lintel) to avoid any tensile strength in the part of brick wall above this lintel or you have another suggestion ?
Best Regards
Refaat
Dear Artur
Greetings
1. Could you find out if I have defined correctly the brick walls as panels have only (compression stiffness) (transfer the slab load to the foundation) or not?
(Please see the capture)
2. Is correct to use the linear release at the boundary of brick walls to prevent any moment transferring between (slab& columns) and brick walls? If so, how do I overcome the instability message (type 1)?
(Please resend the rtd. File after correction)
3. Also, is correct to use a linear support instead of bar (lintel) to avoid any tensile strength in the part of brick wall above this lintel or you have another suggestion ?
Best Regards
Refaat
Dear Refaat,
I'm afraid that modelling a structure like yours in Robot is difficult. The instability is due to both vertical edges of wall in the corner they meet are released. Perhaps a better choice would be to separate both walls from a column and connect them (if needed) with short bars instead?
I don't think that the lintels can be modeled as supports.
I'd say the better approach would be to use the load take down approach which used to be available in CBS but is not part of Robot.
If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.
Artur Kosakowski
Dear Refaat,
I'm afraid that modelling a structure like yours in Robot is difficult. The instability is due to both vertical edges of wall in the corner they meet are released. Perhaps a better choice would be to separate both walls from a column and connect them (if needed) with short bars instead?
I don't think that the lintels can be modeled as supports.
I'd say the better approach would be to use the load take down approach which used to be available in CBS but is not part of Robot.
If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.
Artur Kosakowski
Dear Artur
Thank you for your response.
The main aim of this modelling to do the structural model for (Masonry building confined with RC beams, tie columns and slabs) as shown in the screen shot.
The brick works will be considered as (Bearing walls) and purpose of these tie RC columns to improve the horizontal and vertical bearing walls capacity (Membrane and shear stiffness of walls) whether gravity or seismic loads But (No flexure).
Could you help me how to do the best modelling for this type of structures?
My attempt as you see in the capture below.
1. Could you verify if I defined correctly the Masonry wall as Bearing wall is or not? Because still I have flexure moments at the corners of these walls. Which shouldn’t be appeared.
2. I would like to define the beams just rested on the bearing walls and its transfer only vertical loads to the bearing walls.
3. How do I defined the lintels where don’t have any tensile stress in the upper part of the wall over it.
Note: for your reference I sent you in (PM) full document concerning this structure type
Also , rtd. File is attached
Best Regards
Refaat
Dear Artur
Thank you for your response.
The main aim of this modelling to do the structural model for (Masonry building confined with RC beams, tie columns and slabs) as shown in the screen shot.
The brick works will be considered as (Bearing walls) and purpose of these tie RC columns to improve the horizontal and vertical bearing walls capacity (Membrane and shear stiffness of walls) whether gravity or seismic loads But (No flexure).
Could you help me how to do the best modelling for this type of structures?
My attempt as you see in the capture below.
1. Could you verify if I defined correctly the Masonry wall as Bearing wall is or not? Because still I have flexure moments at the corners of these walls. Which shouldn’t be appeared.
2. I would like to define the beams just rested on the bearing walls and its transfer only vertical loads to the bearing walls.
3. How do I defined the lintels where don’t have any tensile stress in the upper part of the wall over it.
Note: for your reference I sent you in (PM) full document concerning this structure type
Also , rtd. File is attached
Best Regards
Refaat
I'm sorry but I'm not aware of a modelling method of masonry wall with shell type elements which would exactly resemble the way such wall works especially when you want to include lintels. I'd say that typically you just estimate the resultant forces and bending moment acting on such wall (reduced results for panel) and then you design it in the dedicated tool (calculator).
The other option would be to use the software which analyse the load distribution using the load takedown approach as used to be possible in CBS (see the attached picture).
If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.
Artur Kosakowski
I'm sorry but I'm not aware of a modelling method of masonry wall with shell type elements which would exactly resemble the way such wall works especially when you want to include lintels. I'd say that typically you just estimate the resultant forces and bending moment acting on such wall (reduced results for panel) and then you design it in the dedicated tool (calculator).
The other option would be to use the software which analyse the load distribution using the load takedown approach as used to be possible in CBS (see the attached picture).
If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.
Artur Kosakowski
Dear Rafaat,
I'm sorry but I find it difficult to tell you this is right or wrong as shell type surface elements as available in Robot are not intended to model masonry behavior. You can see this looking at the bending moment in beams which is zero as the entire load is transferred to the wall below. Perhaps you could consider modelling the linear releases with elasticity for vertical direction and do the same for the horizontal direction for links among the columns and the walls.
If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.
Artur Kosakowski
Dear Rafaat,
I'm sorry but I find it difficult to tell you this is right or wrong as shell type surface elements as available in Robot are not intended to model masonry behavior. You can see this looking at the bending moment in beams which is zero as the entire load is transferred to the wall below. Perhaps you could consider modelling the linear releases with elasticity for vertical direction and do the same for the horizontal direction for links among the columns and the walls.
If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.
Artur Kosakowski
Dear Artur
Greetings
Thank you for your helpful answer. I shall have been faster to response.
As you see in the first attached capture. I have tried to keep the required interaction between the frame elements (beam & columns) with the masonry wall by blocking (Uy) once and using the linear release with elasticity as you suggested in another once.
. At the same time I need the masonry wall act as purely membrane element in both direction (x&y). So, I reduced the stiffness coefficients as in the second attached capture.
In both tries still there are slight moments and shears values in the wall. (Third capture)
- May I conclude that the shell element doesn’t represent the real modelling of membrane elements even with stiffness reduction and using the linear release?
- Could I consider what I did the best way to model the masonry wall with RC frame in RSA? Or you have another suggestion.
- Shall I use detailed membrane forces or complex membrane forces in order to compare the results with required design resistance (forth capture)?
- In order to avoid any tension in the part over the lintel shall I use very stiff member? If so, what is the properties of this element?
Note : rtd. file is attached
Thanks a lot
Refaat
Dear Artur
Greetings
Thank you for your helpful answer. I shall have been faster to response.
As you see in the first attached capture. I have tried to keep the required interaction between the frame elements (beam & columns) with the masonry wall by blocking (Uy) once and using the linear release with elasticity as you suggested in another once.
. At the same time I need the masonry wall act as purely membrane element in both direction (x&y). So, I reduced the stiffness coefficients as in the second attached capture.
In both tries still there are slight moments and shears values in the wall. (Third capture)
- May I conclude that the shell element doesn’t represent the real modelling of membrane elements even with stiffness reduction and using the linear release?
- Could I consider what I did the best way to model the masonry wall with RC frame in RSA? Or you have another suggestion.
- Shall I use detailed membrane forces or complex membrane forces in order to compare the results with required design resistance (forth capture)?
- In order to avoid any tension in the part over the lintel shall I use very stiff member? If so, what is the properties of this element?
Note : rtd. file is attached
Thanks a lot
Refaat
Dear Refaat,
- May I conclude that the shell element doesn’t represent the real modelling of membrane elements even with stiffness reduction and using the linear release?
Correct. They are not design to behave as masonry.
I'm sorry but I don't have any additional ideas about modelling this type of walls in Robot in addition to these I already posted and I don't think I'm able to make a better model than yours. The only thing I'd consider is to model a walls without openings and lintels and 'taking care' of them designing a wall separately (e.g. in some calculator) based on reduced forces obtained from Robot.
If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.
Artur Kosakowski
Dear Refaat,
- May I conclude that the shell element doesn’t represent the real modelling of membrane elements even with stiffness reduction and using the linear release?
Correct. They are not design to behave as masonry.
I'm sorry but I don't have any additional ideas about modelling this type of walls in Robot in addition to these I already posted and I don't think I'm able to make a better model than yours. The only thing I'd consider is to model a walls without openings and lintels and 'taking care' of them designing a wall separately (e.g. in some calculator) based on reduced forces obtained from Robot.
If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.
Artur Kosakowski
Principal results
You may be interested in the load transfer (direction) and this is nicely illustrated by crosses (last tab) which correspond to principal stresses (1 and 2). See also:
http://forums.autodesk.com/t5/robot-structural-analysis-forum/q1-2-meaning/m-p/6593531
http://forums.autodesk.com/t5/robot-structural-analysis-forum/plate-principal-moments/m-p/5731517
In addition you have the access to the global and total displacements from there.
complex results (Mises)
Total value of stress in a structure with steel walls e.g. a tank or silo.
If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.
Artur Kosakowski
Principal results
You may be interested in the load transfer (direction) and this is nicely illustrated by crosses (last tab) which correspond to principal stresses (1 and 2). See also:
http://forums.autodesk.com/t5/robot-structural-analysis-forum/q1-2-meaning/m-p/6593531
http://forums.autodesk.com/t5/robot-structural-analysis-forum/plate-principal-moments/m-p/5731517
In addition you have the access to the global and total displacements from there.
complex results (Mises)
Total value of stress in a structure with steel walls e.g. a tank or silo.
If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.
Artur Kosakowski
Dear Artur
Greetings
Thank you to point me to these threads which are explained the theoretical bases of (Principles & complex results). Moreover I have read the help contents related to the same subject.
So, my understanding as following. Please could you review it and correct me?
1. The principle stress value in each principle direction = the stress value in each direction whether (1) or (2)) + (the stress value (12)).
Whereas the crosses represents ((the direction of principle axis of each finite element and the arm length represents the stress magnitude)).
2. Complex value represents the reduced stress value of each finite element which also include the stress value (XY).
Since both of them (Principle & complex) is included plane stress value ((12) &(XY)) respectively .
My inquiry :
Still I am confused Which one of them (Principle or Complex) shall I used to compare it with the stress design value (e.g. Masonry wall or Concrete wall …etc ) (second capture)?
Or shall I compare the stress design value with the stress value of detailed results for each direction?
Thank you a lot
Refaat
Dear Artur
Greetings
Thank you to point me to these threads which are explained the theoretical bases of (Principles & complex results). Moreover I have read the help contents related to the same subject.
So, my understanding as following. Please could you review it and correct me?
1. The principle stress value in each principle direction = the stress value in each direction whether (1) or (2)) + (the stress value (12)).
Whereas the crosses represents ((the direction of principle axis of each finite element and the arm length represents the stress magnitude)).
2. Complex value represents the reduced stress value of each finite element which also include the stress value (XY).
Since both of them (Principle & complex) is included plane stress value ((12) &(XY)) respectively .
My inquiry :
Still I am confused Which one of them (Principle or Complex) shall I used to compare it with the stress design value (e.g. Masonry wall or Concrete wall …etc ) (second capture)?
Or shall I compare the stress design value with the stress value of detailed results for each direction?
Thank you a lot
Refaat
Or shall I compare the stress design value with the stress value of detailed results for each direction?
IMHO there is no point to look at von Mises stress for masonry and following the changes in the direction of stresses would be not practical so I'd look at the vertical and horizontal directions instead.
If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.
Artur Kosakowski
Or shall I compare the stress design value with the stress value of detailed results for each direction?
IMHO there is no point to look at von Mises stress for masonry and following the changes in the direction of stresses would be not practical so I'd look at the vertical and horizontal directions instead.
If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.
Artur Kosakowski
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