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mesh-geom(Inclined site inclined pile foundation)

Posted: Fri Oct 28, 2022 1:34 pm
by amb_1
Dear STKO team
I'm having some problems with meshing.

Can I use energy absorption boundaries when my model boundaries are skewed? When using a damped boundary, do you still propagate at 0.5?

Geometry:
1. When the model established by solidworks software is imported, the external surface and adjacent surface of circular pile foundation are seriously deformed, and the two surfaces are embedded into each other, which makes it impossible to achieve a good interface between different models. May I ask how to deal with it? When using STKO modeling, there is no similar phenomenon, but the complex model solidwork is more friendly. Could you add a dimension standard function in the geometric modeling? When changing the size, the model automatically changes (like solidworks), especially the Angle labeling, while at this stage, only the reconstruction can be deleted, and for tilted models, it is very troublesome.
2, in addition, I encountered a very troublesome problem, modeling, using a straight line to capture, can only capture the midpoint and end points, for complex model non-midpoint, the operation is very troublesome, it is difficult to capture the line, often more than the line, may I ask in the next version, can you add a new function? When near the model edge line, the node automatically adsorbs to the nearest line, similar to solidworks CATIA software provides similar function (automatic adsorption).


Mesh:
3. A new problem is encountered when cutting models. The model does not provide cutting tools. Similar functions such as subtract and intersect require model establishment for segmentation, which is extremely inconvenient for complex models. In the future version, it will provide a function for model cutting. Combining coordinate system, it can use lines, planes and points to segment the model, which is very convenient for complex models of opposite characteristics, similar functions such as solid edit in hypermesh
4. A triangular slope cannot be divided into a hexahedral grid (like a cube), can you provide an example?
5, the circular pile foundation can not be divided into structural grid, must be divided, and if it is inclined pile (inclined pile foundation, it is difficult to be divided in modeling), can you provide a case about inclined pile?
6. In the Mesh part, compared with hypermesh, the convergence of Mesh control algorithm is not too good (the main problem is the generation of structured mesh), and the topology mapping between layers is not too good, and mesh dislocation often occurs. Do you have plans to further optimize the mesh algorithm in the future? Or add a model-to-model interface? (For example, the button interface of hypermesh ensures that adjacent surfaces of different models have common nodes.
7. Can a new function be added in the post-processing of the model? In addition to the box selected node, input coordinates, can get a neighboring point information (like FLac3D input coordinates, can detect the nearest point around the coordinate). The information of the internal nodes of the model is extracted, and the nodes inside the model need to be hidden constantly, and often errors are made, and the box is often selected to the nodes that are not needed
8. Regarding the interfaction function, can you provide an example of how generlink works? And if you use workplane, model segmentation
9. Thank stko team for providing such a good tool.!

Re: mesh-geom(Inclined site inclined pile foundation)

Posted: Wed Nov 02, 2022 11:53 am
by STKO Team
Geometry:
1. When the model established by solidworks software is imported, the external surface and adjacent surface of circular pile foundation are seriously deformed, and the two surfaces are embedded into each other, which makes it impossible to achieve a good interface between different models. May I ask how to deal with it? When using STKO modeling, there is no similar phenomenon, but the complex model solidwork is more friendly. Could you add a dimension standard function in the geometric modeling? When changing the size, the model automatically changes (like solidworks), especially the Angle labeling, while at this stage, only the reconstruction can be deleted, and for tilted models, it is very troublesome.
2, in addition, I encountered a very troublesome problem, modeling, using a straight line to capture, can only capture the midpoint and end points, for complex model non-midpoint, the operation is very troublesome, it is difficult to capture the line, often more than the line, may I ask in the next version, can you add a new function? When near the model edge line, the node automatically adsorbs to the nearest line, similar to solidworks CATIA software provides similar function (automatic adsorption).
Thanks for all these suggestions, we are continuously integrating new commands into STKO, so we will take them into account.


3. A new problem is encountered when cutting models. The model does not provide cutting tools. Similar functions such as subtract and intersect require model establishment for segmentation, which is extremely inconvenient for complex models. In the future version, it will provide a function for model cutting. Combining coordinate system, it can use lines, planes and points to segment the model, which is very convenient for complex models of opposite characteristics, similar functions such as solid edit in hypermesh
You can draw auxiliary nodes/edges/faces and use them in the Merge command. It will create partitions of the source geometry.


6. In the Mesh part, compared with hypermesh, the convergence of Mesh control algorithm is not too good (the main problem is the generation of structured mesh), and the topology mapping between layers is not too good, and mesh dislocation often occurs. Do you have plans to further optimize the mesh algorithm in the future? Or add a model-to-model interface? (For example, the button interface of hypermesh ensures that adjacent surfaces of different models have common nodes.
The constraint of having the same mesh size on two parts of different geometries is already in our todo list, thanks for the suggestion


7. Can a new function be added in the post-processing of the model? In addition to the box selected node, input coordinates, can get a neighboring point information (like FLac3D input coordinates, can detect the nearest point around the coordinate). The information of the internal nodes of the model is extracted, and the nodes inside the model need to be hidden constantly, and often errors are made, and the box is often selected to the nodes that are not needed
Whenever you don't have a built-in function in STKO, you can try the more versatile Python API in STKO. If you don't know how to use it, please have a look at our webinar on the Python API.
Here is a script you can use to do what you want:
FindNearestNode.zip
(1.32 KiB) Downloaded 345 times
FindNear.png
FindNear.png (465.73 KiB) Viewed 8408 times


Regarding all the issues you had with creating structured meshes out of triangular or circular shapes, here you can find possible solutions:
zhiyouchangwenti.zip
(5.5 MiB) Downloaded 349 times

For the triangle, you can create lines, like these, and then do a sweep.
SW_sweep_lines.png
SW_sweep_lines.png (93.34 KiB) Viewed 8408 times
It will create faces that you can use to partition your model in the merge command:
SW_sweep_cutting_planes.png
SW_sweep_cutting_planes.png (165.97 KiB) Viewed 8408 times
SW_sweep_final_mesh.png
SW_sweep_final_mesh.png (113.35 KiB) Viewed 8408 times


For the circular shapes, you have 2 options. In both cases you need to make the circular face have 4 corner nodes, or divide it so that each sub-face has 4 corner nodes:
SW_cyl_geom.png
SW_cyl_geom.png (85.51 KiB) Viewed 8408 times
SW_cyl_mesh.png
SW_cyl_mesh.png (237.54 KiB) Viewed 8408 times

Re: mesh-geom(Inclined site inclined pile foundation)

Posted: Thu Nov 03, 2022 9:44 am
by amb_1
Dear Team STKO
Thank you very much for the solution. I have found a solution to convert the common STEP file with the function of SW software, and the effect seems to be very good at present. I am looking forward to STKO better future and looking forward to STKO developing a set of tools for model cutting in the future.
In addition, I would like to ask a question about the volume force of the soil. When considering the acceleration(Z = -9.81) of gravity, is it not necessary to load the volume Force of the soil in a linear way(Add linear series in Definitions)?
when I refer to the OpenSees and OpenSeesPL cases, there is no linear loading of the soil volume force.
Best regards
PDMY ASDAsorbingBoundary3D nonlinear absorption boundary, do you have a lecture scheduled recently? It is not very ideal to simulate PDMY by using elastic ASDAsorbingBoundary or Bingboundary

Re: mesh-geom(Inclined site inclined pile foundation)

Posted: Fri Nov 04, 2022 8:30 am
by STKO Team
When considering the acceleration(Z = -9.81) of gravity, is it not necessary to load the volume Force of the soil in a linear way(Add linear series in Definitions)?
If you add the body force to the element property, it will be already considered, so there is no need to add the volume force.
Note that the body force in an element is applied instantaneously. That's why we implemented the Volume force automation. It converts the user-defined volume-force(per unit volume) into a set of equivalent nodal forces that can be added into a loadPattern, therefore they can be applied according to a timeSeries.
PDMY ASDAsorbingBoundary3D nonlinear absorption boundary, do you have a lecture scheduled recently? It is not very ideal to simulate PDMY by using elastic ASDAsorbingBoundary or Bingboundary
We are still working on it.

Re: mesh-geom(Inclined site inclined pile foundation)

Posted: Fri Nov 04, 2022 1:12 pm
by amb_1
Thanks

Re: mesh-geom(Inclined site inclined pile foundation)

Posted: Sat Nov 05, 2022 1:30 am
by amb_1
Dear Team STKO,
I'm sorry, I encountered a question, when I need to consider the boundary simulation actual ground conditions, OPenSeesPL website provides a boundary condition to simulate the boundary of the centrifuge test (Periodic boundary), the principle of it is to assume that the boundary of the master node equals the slave node displacement along the grid (developed by shear boundary),
微信图片_20221105093026.jpg
微信图片_20221105093026.jpg (36.47 KiB) Viewed 8372 times
However, I cannot achieve similar functions in STKO, could you please help me?
微信图片_20221105093110.jpg
微信图片_20221105093110.jpg (19 KiB) Viewed 8372 times

Re: mesh-geom(Inclined site inclined pile foundation)

Posted: Mon Nov 07, 2022 3:20 pm
by STKO Team
You can do periodic condition in OpenSees. It's the EqualDOF MP constraint.
However there is a theoretical problem in your model.
You cannot make periodic conditions if the two sides have different heights (it does not have a physical meaning).
If the solution vector should be periodic, the mesh also must be periodic:
Periodic.png
Periodic.png (61.78 KiB) Viewed 8342 times

Re: mesh-geom(Inclined site inclined pile foundation)

Posted: Tue Nov 08, 2022 4:13 pm
by amb_1
Thank you I see

Re: mesh-geom(Inclined site inclined pile foundation)

Posted: Wed Nov 09, 2022 9:15 am
by STKO Team
You're welcome