December 24, 2018 at 1:19 amyasser1987Subscriber
i want to model a soil under tripod bucket offshore foundation and getting the displacement and rotation by applying wave load , the soil should be modeled with mohr Colomb theory and it is sandy clay, but unfortunately i do not know how to do it , could you please someone help and guide me, i mean if there is any tutorial or sample project could please introduce to me actually i do not know which steps must be followed on ansys workbench19.1 in order to simulate the soil,i?step by step approach
December 24, 2018 at 3:05 ampeteroznewmanSubscriber
Here is a discussion on Mohr-Coulomb material model.
December 24, 2018 at 1:56 pmyasser1987Subscriber
many thanks, Peter
but you know my problem is that i do not even know how to model it on Ansys I mean step by step to simulate the soil on ansys, for example how to make a model !how to apply the boundary conditions and theories ! which analysis system or costume system should be used for modeling a soil in the workbench 19.1
I am familiar with Abaqus and but I am not familiar with ansys, do you think if there is any project or tutorial in order to learning soil modeling by ansys
please help and guide me i got stuck in project
December 24, 2018 at 4:13 pmpeteroznewmanSubscriber
There is a lot to learn. Do you already know a CAD system? If not, then you must start to learn SpaceClaim that comes with ANSYS.
For this model, you are interested in the sand and its ability to withstand the loads from above, so the structure above can be simply a way to transfer load to the buckets.
I assume you don't care about the stress in the bucket material and how the top of the bucket connects to the tower. You need to draw three buckets in SpaceClaim or your own CAD system. The buckets are just simple cylindrical surfaces with a flat top, and construct solid bodies that represent the soil that is in each bucket and outside all the buckets out to a radius of 3*(S+D) and below the buckets to a depth of 3L.
Start reviewing some tutorials on SpaceClaim in the Tutorials section of this site.
Please provide the dimension of L, D and S and I will create a tutorial using this example.
You marked this discussion as Solved, by clicking on the Is Solution link above. That was a mistake as many people will not read discussions marked as solved because that indicates there is no need for any more help. I will help you get the geometry you need, then you can start a New Discussion for how to build the model with that geometry in Mechanical.
December 24, 2018 at 8:01 pmyasser1987Subscriber
i really appreciate your response
yes actually i don't care about the stress in the bucket material and top of bucket i assume is integrated with the tower, however, in reality, they are welded together
i want to see and get the Deformation and rotation of structure when the sea wave load is applied to the structure
The bucket diameter is varied as 6, 9, 12, and 15 m
skirt thickness was fixed at t=25 mm
skirt length is varied as 3,4.5,6
i also attached those pictures in order to be cleared
Mr,Peter please help and guide me
December 24, 2018 at 8:14 pmpeteroznewmanSubscriber
Should the buckets be considered rigid or flexible?
December 24, 2018 at 9:02 pmpeteroznewmanSubscriber
Here is the geometry step. I found after I imported the geometry into Mechanical that the tops of the buckets were merged (lost), so I have to copy/paste the bucket tops to get them back.
December 24, 2018 at 10:40 pmpeteroznewmanSubscriber
Here is more geometry prep in part2
December 24, 2018 at 10:55 pmyasser1987Subscriber
should be considered as a rigid body
December 24, 2018 at 11:10 pmpeteroznewmanSubscriber
Here is the model building to define contacts, loads and supports.
December 25, 2018 at 4:48 pmyasser1987Subscriber
many thanks for your help,you are amazing
no one in my life did such this favor to me already
i have followed your steps and tutorials up to now ,
what would be the next steps ?
December 25, 2018 at 7:13 pmpeteroznewmanSubscriber
December 25, 2018 at 9:29 pmpeteroznewmanSubscriber
December 25, 2018 at 9:59 pmpeteroznewmanSubscriber
Part 6: Building a better mesh.
December 26, 2018 at 5:30 pmpeteroznewmanSubscriber
Part 7: Results from the better mesh
December 28, 2018 at 12:17 amyasser1987Subscriber
dear Mr Peter
many many thanks for your help i have no words to express my appreciation
i have problems
first of all , when i defined the material properties in the engineering data then i go for refreshing the project, in the model option the question mark appears not the mark shows it's ready for solving
but after that when i go into project i can assign the materials that i have already defined to the buckets and the soils and then i followed your setting for the mesh and solving then click on the solve tab but i have faced with this error
please guide me
December 28, 2018 at 2:34 ampeteroznewmanSubscriber
Please follow the directions for creating a Workbench Project Archive .wbpz file. Then attach that file to your reply. I can look in that file to see what is wrong. Note that the file must be less than 120 MB to attach. You might need to RMB on Model and Clear Generate Data to reduce file size.
December 28, 2018 at 10:58 amyasser1987Subscriber
December 31, 2018 at 4:39 ampeteroznewmanSubscriber
Sorry for the delay in replying.
I downloaded the archive you saved in the previous post. You seem to have overcome the problem in the post that had the ? in the Model item. This model actually started solving.
If you click on Solution Information, you will see a long text file of the solver output. One of the messages is this:
*** WARNING *** CP = 14.125 TIME= 8:28
The material solution failed for element 6063 with material 11.
*** WARNING *** CP = 14.125 TIME= 8:28
The material solution failed for element 6069 with material 11.
This means that the displacements that went into the mohr-coulomb material model did not compute a valid output. This often happens with Geomechanical materials like mohr-coulomb. All my examples in the model building videos used simple linear elastic materials.
Here is an illuminating discussion where a member was trying to compute stresses in a mine shaft. As soon as the mohr-coulomb material model was added, an error occurred. It was because the model boundary conditions (Fixed Supports) generated tensile stresses that the mohr-coulomb material model couldn't handle. As soon as better boundary conditions were applied, the model solved because there were no longer spurious tensile stresses.
I recommend you make a very simple model of some soil and a wall, as simple as you can think of, and use that model to see how to get the mohr-coulomb material model to solve. Maybe a rectangular block of soil in a rectangular bucket. Move one wall of the bucket in or out and see what happens.
Let's close this discussion, as it was a good example of how to do everything except the soil. Please create a New Discussion to ask questions about this new simple model that uses mohr-coulomb, because this discussion is already marked as solved.
December 31, 2018 at 5:26 pmyasser1987Subscriber
Many thanks for being a considerate and helpful person,
unfortunately, it is not solved yet,
i want to ask you if you run it without any problem ???
because when i start to run( exactly the file I upload for you), i am facing with this error and stops, i do not what to do i checked again all parameters but did not work
could you please if is possible to share the model that you made with me? in order to get rid of the error
sorry if i bother you with asking many questions since my project got stopped for 4days and running late for its deadline
furthermore, if you agree i will create new discussion after solving the error otherwise I'll create a new topic
December 31, 2018 at 7:42 pmpeteroznewmanSubscriber
If you take the model you attached above, and scroll up in the Solution Output, you will see the warning messages I showed you about the material.
If you open that model and in Engineering Data, delete the Mohr-Coulomb model from the soil, Refresh the Project and Solve the model, it will solve without error. That archive is attached.
That is why you need to take some time to understand the Mohr-Coulomb material model and ask questions in a New Discussion.
- You must be logged in to reply to this topic.
Simulation World 2022
Earth Rescue – An Ansys Online Series
- How to calculate the residual stress on a coating by Vickers indentation?
- Errors – Reinforced Concrete Beam
- An Unknown error occurred during solution. Check the Solver Output…..
- Solver Pivot Warning in Beam Element Model
- The solver engine was unable to converge on a solution for the nonlinear problem as constrained.
- whether have the difference between using contact and target bodies
- Massive amount of memory (RAM) required for solve
- Cannot apply load on node
- Large deflection
- Colors and Mesh Display