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Victor
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Comments
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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…
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On second thought, please don't publish a user.config from Mecway on the internet because if you're a paid customer, it contains your product key which is private. Perhaps send this through email instead.
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I would think any dynamic analysis could be used as inertia relief, even if it's inefficient on computer resources. Either use a single time step or have damping so the final state is a rigid body acceleration with deformation from the loads. Note…
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Sorry about the late reply. The oscillation is because the initial condition is the undeformed state, so it falls down under gravity, then bounces back and oscillates. Mecway doesn't currently allow non-zero initial conditions so you might have to u…
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1. Yes except with the Tsai-Wu criterion instead of von Mises.2. Yes 3. Yes except it only checks the top and bottom of each layer, not anywhere in between.
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Not quite a tutorial, but here's a quick example of the Tsai-Wu failure criterion: Make a model with shell elements and a laminate material. Enter the parameters in Material Properties ->Failure criteria -> Tsai-Wu Solve and see the result…
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That's a very nice tutorial but I think it's too dated to be much use for Mecway. It doesn't seem to have examples of the different-materials-on-each-layer type of laminate material which is the only one that Mecway and LISA have now. There's an…
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Self weight isn't automatic so yes, you have to specify -9.81m/s^2 gravity.
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It looks like SAP's two formulas might be equivalent (I haven't checked) and the latter is the one it actually uses but the former, with the integral, is more intuitive as a definition.
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Not directly but two ways around it: if you have base excitation of a rigid base, then you can use a fixed base with gravity load on the whole structure as acceleration. You can copy and paste tables of time-acceleration data into that. You coul…
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I'll look into adding the membrane forces. For out-of-plane shear forces, LISA's results often had quite large errors so I removed them from Mecway. I'm not sure what was wrong with them. The attachments show the kind of errors to expect. The plat…
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Please attach the user.config. Maybe it's not correct.
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Just curious what makes this problem challenging. Is it hard for solvers to converge? Or something complicated about the boundary conditions or the load changes while it's deforming?
