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Showing results for tags 'fea'.
setspeed posted a topic in Autodesk InventorI'm a mech engineering student and I have no experience whatsoever using any CAD. For a project I'm doing, I want to produce (or even better, have someone do it for me!) a 3D CAD model for a bicycle frame, and then test it against industry standards for fatigue life. I need to some guidance on what the best way to go about this is. I gather Inventor can be used to produce the model, although I have downloaded and started playing with Inventor Pro 2013 Student Edition, and it's intimidating to say the least. Getting to grips with it and trying to produce a model is going to take a very very long time. I don't want to invest this time if A) there is a better route B) I can find someone to do it for me The project is not about my personal ability to produce models, and this part of it is only going to be a time-sink/distraction from my actual aims. Furthermore I gather that Inventor cannot do fatigue-life analysis, but Autodesk Simulation does? I'm thinking that perhaps I can use the stress outputs from Inventor's FEA modelling to then hand calculate fatigue life - it would probably be quicker than spending days and days struggling with yet another package I don't know how to use. Is this feasible? I'm pretty much all at sea with this (computer) stuff, I haven't been taught it practically, and any suggestions on how to proceed are gratefully received (even if those suggestions are 'Use this other package which is simpler and quicker to get up and running on').
Dear all, I have two parts that put together. Basically a triangular ring is put into a hole of a hollow cylinder. The triangular ring (0.5 dia) could freely move inside the hole (0.625 dia). I need to do a FEA analysis, my steps are 1. I mate the centerline of the hole to one of the axis of the triangle ring, so they line up (as least visually), then click OK. AND then delete this constraint 2. Start FEA analysis, put fix constraint at the bottom of the cylinder, add force to the ring 3. ADD 2 contacts (separation, no sliding) 4. RUN I cannot believe the result. I apply 50 lbf only, but the safety factor is close to zero. Do my steps right??? Pictures and parts are attached. Inventor 2014 Question.zip
Well, I have just realized why the people do not use FEA (finite elements analysis) as often as they should do: FEA preprocessing phase is a disaster!!! Simply speaking - there is no simple, efficient meshing software available on the market. Existing software like Hyper Mesh is just an interface catastrophe. Everything you hate in a computer software interface is existent there! OK - being serious. The problem seems to start at the beginning. Engineering design applications are NURBS driven. They describe surface in a topology unaware manner. Then the project goes into FEA preprocessor where appropriate mesh topology is being created for further analysis. Well - while contemporary FEA preprocessors are powerful in terms of handling various mesh types, they are extremely poor modelling tools compared to professional modelling tools like 3DS Max or Maya. Simply speaking - any 3D artists is able to deliver a model with nice surface mesh topology: definitely this model will be better than result of automatic meshing by FEA preprocessors or even better than human-optimized meshes delivered by inexperienced FEM engineer! The only problem is... how to proceed from surface (2d) mesh to volume (3d) mesh keeping surface topology of the input geometry? Or rather - the real issue is that I never heard about a FEA preprocessor accepting surface mesh data as input geometry. Why??? There are efficient algorithms generating volumetric 3d mesh from 2d surface mesh (volume tessellation) but FEA preprocessrs do not implement them. Why??? Would you be so kind to explain why such a streamline is non-existent in practice?: 1) Model construction in 3DS Max or similar application as surface mesh (triangular, tetra or even hexa is possible). Basic topology optimization is achieved already during modelling phase. 2) Convert surface mesh model into volume mesh model preserving imported surface topology. 3) Import generated 3D mesh into FEA preprocessor and apply materials, loads, constraints. 4) Export to solver. The reason for the question is simple: an hour of 3D modeler (an "artist") work is much cheaper than an hour of FEA engineer while 60% of FEA engineer workload is... meshing !!! Would you be so pleased, to comment???