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Victor
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Thanks for the comments. I don't intend to ever include node coordinate transformation as a visible feature in Mecway. It's not a physically real concept and there should always be an more conceptually simple way of achieving the same result. Mecw…
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You can use circular tubes. CCX expands them to square sections, presumably with a special stiffness matrix.
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This is a tricky one. The maximum setting is sometimes very slow. If it remembers the setting then people will turn it up once on a small model where it doesn't make a difference then suffer the slowness later on with a bigger model and it won't be …
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Here it is with the disconnected edges joined by bonded contact. TIE doesn't work here. I think it's because the webs intersect the flanges. You might have to separate them by half the material thickness to use TIE.
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That's curious about the mesher creating mismatched edges. Perhaps because of 3 surfaces intersecting at one edge which is not something it's supposed to handle. Bonded contact doesn't typically add much to the solution time unless the contact r…
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While you have to use different components for different thicknesses, they can still be connected by shared nodes without needing any kind of contact or tie. You can split one component into two by selecting the required elements and making a new co…
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Node selections are currently not carried through with the CCX solver. That's because it's more complicated than elements and faces when CCX generates extra nodes on shells and beams. The closest way would be to use a face or element instead, but …
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Just a note in case of overlooking the functionality - You can apply distributed loads to shell edges instead of using node forces like this. First select the nodes, then switch to "Select faces" mode and the edges will be selected, even though they…
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Hello. Please see this thread for instructions: http://mecway.com/forum/discussion/comment/1703/
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Andrea, what's holding me up is how to do it appropriately. If there's just an extra option for every element to use reduced integration then it will be an obstacle for more people than it helps. Whenever something doesn't work, it'll be tempting to…
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Thanks Andrea. At some point, I'll do a bunch of experiments and research into this. From this example, it looks like an optimization that's not very important since you could just refine the mesh a little more or use quadratic elements in bending d…
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Here's the example from the book with results that match all the digits shown in the book for strain and displacement. You may already know this but a key difference is that if you apply opposing forces like the book shows, they have to be exactly…
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Thanks Andrea. That helps a bit. It still seems like a bit of a black art. It's looking like it should be set by both element shape and component.
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I'm still not clear on when reduced integration should and shouldn't be used so I don't want to commit to having it saved with the model yet.
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I don't have a timeline for version 7. But some things it has are distributed moment loads on faces, pressure XYZ can be a function of position, stress linearization doesn't require nodes to be on the SCL line, and more features work with CCX.
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You can use these settings: Analysis type: Nonlinear Static 3D Solver: CCX Material: Mechanical type = Isotropic, plastic type = bilinear Here's an example with a force that increases with time that causes elastic deformation initially, then p…
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If any of the named selections correspond to one part, you can click that to select its elements then add a new component with the selected elements. Otherwise, you could use View -> Open cracks to separate the parts so you can select one. To…
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For a rectangle like this, you can make it from a single element then use Mesh tools -> Refine Custom to get a structured mesh. Usually those distortions don't matter though. What's the reason for wanting the elements to be square?
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There's currently no feature for that, sorry. Alternatives for checking accuracy are looking at the size of stress discontinuities in the element values in the solution or a mesh convergence study.
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That's a remarkably clear and thorough example of a mesh convergence study. Thanks for posting it. Stress concentrations and mesh convergence are some of the major causes of confusion with FEA and your report shows their significance very nicely.
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OK no problem.
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I'm not sure if I understand you, but it sounds like you want to prevent them from deforming, so they act as a rigid body? A simple way is to set a very high Young's modulus. If you only want to constrain their joint to 90 degrees but still allow …
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The cutting plane has been in all versions and is the slider at the top-right of the toolbars. Slide it half way to hide the front half of the mesh.
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From these pictures, the negative values only seem to be patches in the middles of elements, so it looks like just the interpolation used by the display and you can ignore it. The node value look to be all non-negative. The existence of patches co…
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The values at the nodes should always be nonnegative. A common way nonphysical results like these can appear is through the interpolation for finding values between nodes. It uses the elements' shape functions to interpolate the colors on the displa…
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Yes and yes.
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Two main approaches: A) Use a reference frame rotating with the blade. Linear dynamic analysis is probably sufficient since there are unlikely to be any large displacements. It depends how much rotational vibration the shaft has because angu…
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That can be a bit of a problem. You should be able to work around it by setting a larger number of time steps and a corresponding smaller time step size. Then the automatic time stepping should bring that back to a sensible size as it solves. The nu…
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1) Set the environment variable OMP_NUM_THREADS = 8, where 8 is the number of threads you want. It might be best to make that a bit less than the actual number of cores, but I'm not sure. This PC -> Properties -> Advanced system settings ->…
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I used trial and error until it damped the oscillation for most of the time steps. There isn't really a proper value since it doesn't represent a real damping effect. It's only valid if none of the time-dependent loading (ie. accelerations) have any…
