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how to build a "L-shape dam" structure?

Posted Mar 24, 2012, 7:04 p.m. EDT Geometry Version 4.2a 3 Replies

Ted Zhang
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Hi, All,
I was trying to build a 3-D "L" shape structure, like "dam". the bottom of the structure is bigger than the top. I know for a simple "rectangular" top structure, you could use the block of "Hexahedron" by inputting the 8 vertices position. for my "L" shape "dam", I think I need to decide 6x2=12 vertices positions, but i don't know how to do it. I used to use "extrude" to draw the structure with same bottom and top size. Could anyone give some suggestions?

regards,
ted
3 Replies Last Post Mar 30, 2012, 7:27 a.m. EDT
Victor Manuel Rodriguez Zermeno
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Posted: 1 decade ago Mar 25, 2012, 2:58 p.m. EDT
You can use several solids (including hexahedrons) and the use the boolean operarions.

Victor
You can use several solids (including hexahedrons) and the use the boolean operarions. Victor
Ted Zhang
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Posted: 1 decade ago Mar 26, 2012, 1:37 a.m. EDT
Hi,
actually I did build a "L" structure using 3 hexahedrons(2 as arms and one as the center corner) at the beginning, but they are the same size between top and bottom. then I tried to change the bottom layer vertices position, to make the bottom wider for both of the arms, it does look like a "dam" now. however, when I try to mesh this structure, I have a error message. I attached the model.

regards,
Hi, actually I did build a "L" structure using 3 hexahedrons(2 as arms and one as the center corner) at the beginning, but they are the same size between top and bottom. then I tried to change the bottom layer vertices position, to make the bottom wider for both of the arms, it does look like a "dam" now. however, when I try to mesh this structure, I have a error message. I attached the model. regards,
Victor Manuel Rodriguez Zermeno
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Posted: 1 decade ago Mar 30, 2012, 7:27 a.m. EDT
I just looked at your file and I see the problem. First of all, you want to increase the thickness of your drawing while you work on it, use parameters and scale z by 10 or 20. Later you can change the parameter value and fix this. You can ease things up if you increase the length of the arms so that they meet at the center. Then you save one hexahedron. I tried this and it worked but the mesh again made the problem. Here is other idea: Use the two hexahedrons as I suggest and using 2 work-planes build two quadrilateral figures where the arms meet. Then extrude them out. That will build the same figure but in a different internal way. Maybe you will get lucky here.
Finally, I suggest that you send your file to support but with the z distance increased by a factor of 20 and ask them to help you. Your model is correct and the problem is with the geometry builder and the mesher, not the actual design.
I wish I could give you more advise, but that is all I have.
Cheers,
Victor
I just looked at your file and I see the problem. First of all, you want to increase the thickness of your drawing while you work on it, use parameters and scale z by 10 or 20. Later you can change the parameter value and fix this. You can ease things up if you increase the length of the arms so that they meet at the center. Then you save one hexahedron. I tried this and it worked but the mesh again made the problem. Here is other idea: Use the two hexahedrons as I suggest and using 2 work-planes build two quadrilateral figures where the arms meet. Then extrude them out. That will build the same figure but in a different internal way. Maybe you will get lucky here. Finally, I suggest that you send your file to support but with the z distance increased by a factor of 20 and ask them to help you. Your model is correct and the problem is with the geometry builder and the mesher, not the actual design. I wish I could give you more advise, but that is all I have. Cheers, Victor

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