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Showing results for tags 'bending'.
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Hi, I have some questions I was hoping someone could answer. I am trying to model a sandwhich structure with carbon fibre skins and aluminium honeycomb core and then perform a 3 point bending test in the software if possible. 1. Could someone please explain what the reason is for selecting PCOMPP, PSOLID etc, what are the reasons for choosing one of them over another? 2. Which compersite property: PCOMPP, PSOLID, PSHELL, etc, do I need to select for the task I want to achieve (3-point bending simulation)? 3. Another question relates to my understanding of the MAT 8 card....would I be correct in saying that as MAT8 only asks for the in-plane properties, it would not be possible to get proper results for a 3-point bending test in the software? (Or does the software still work this out?) 4. Would I need to use the MAT9 card for what I am trying to do and in that case what composite property do I select, PCOMPP, PSOLID, PSHELL, etc? 4. If I select for example PCOMPP for the honeycomb properties, do I have to select PCOMPP for the carbon fibre skin properties? Regards
Hey Guys! I have experimental data for composite tension compression and bending (3-point and 4-point) due to my university and I want to make a material card that can describe all of the mentioned test (and behavior) with proper accuracy. I would like to make tension, compression and bending (3-point and 4-point) test in Optistruct but I haven't make coupon test before. In the real tests the loads (movement of the clamping jaws) move at constant velocity. I have no experiment how to model such kind of load in Optistruct. I think there should be some non-linearity in the test because of the large displacement. How should I properly model such kind of problem? Do you have any experiment in modeling with velocity load in Optistruct? A further problem will be the bending tests where I think I should use contact surface to model the geometry of the bending machine tool's head. In Optistruct I used slide contact before, but it didn't work to well because of large displacement. Is it possible the handle open gap contact and make the 3-point/4-point bending in Optistruct? If you have any model for bending and tension and compression could you share with me? I would like to study the pre-process method to understand the nature of the coupon test in Optistruct. Thank you for your help and advise in advance! Best regards, Tüki
As far as I understand, the mises stress at the middle of the shell element is membrene stress, and the mises stress at the surface of the shell element is sum of the membrene stress and bending stress. and the hyperview can show the stress of the mid layer and both surface layer of the elements.(Z1, Z2, or Max) How can I show the contour plot of only the bending stress of the element ? I mean that I want to get the contour plot of value of ((Z1, Z2 or Max) - Mid layer ). Thanks for your help in advance.
Hello guys, I'm currently trying to simulate a 3 point bending test to get the best material arrangement for high bending stiffness in a composite monocoque, while keeping the weight low. The laminate i strive for is a sandwich structure with an aramide honeycomb core in the centre and three plies of different material on top and on the bottom. These are the steps I did so far: 1) I created a CAD model, imported it to HyperMesh, organized the componets (specimen, impactor, support) and meshed them with 2D elements. 2) I created the materials. MAT1 for the impactor and the support of the 3 point bending test, MAT8 for the different plies and MAT9ORT for the honeycomb core. 3) After that I created the properties. PSHELL with an elementthickness of 2 for the impactor and support, PCOMPP for the plies and PSOLID with the honeycomb material for the core. 4) Then I created the different plies. 6 with the MAT8 material for the top and bottom layers and 5 with the MAT9ORT material for the core to get a total of 5 elements over the thickness of the core. The material type for all plies is ORTHOTROPIC. 5.1) I created a laminate with the 5 core plies and then did a "shell to solid conversion" with this laminate. After that I got a new component with 5 elements over the thickness. [5.2) In a second try I did the "shell to solid conversion" with the plies of the core which led to the same result as 5.1] 6) I assigned the PCOMPP property to the specimen elements, otherwise the laminate and layers weren't visible over 2D detailed element representation. 7) I updated the laminate with the other 6 plies. 8) Finally I created the load collectors and the load step, an output request for CSTRAIN and CSTRESS 9) I started OptiStruct to run the analysis. But after a few seconds i got these errors: *** ERROR 14: Missing MAT # 5 referenced by PLY # 7, (existing MAT with this ID is of incorrect type). *** ERROR 14: Missing MAT # 5 referenced by PLY # 8, (existing MAT with this ID is of incorrect type). *** ERROR 14: Missing MAT # 5 referenced by PLY # 9, (existing MAT with this ID is of incorrect type). *** ERROR 14: Missing MAT # 5 referenced by PLY # 10, (existing MAT with this ID is of incorrect type). *** ERROR 14: Missing MAT # 5 referenced by PLY # 11, (existing MAT with this ID is of incorrect type). *** Errors with missing, incorrect or duplicate IDs found 5 times. So when I got back to the model to check the properties, I wasn't sure if the PSOLID property and the MAT9ORT material are assigned to the plies in the laminate or to the new created component for the solids of the conversion. I want to get a laminate with from top to bottom: 3 layers of PCOMPP MAT8, the PSOLID MAT9ORT core and then 3 layers of PCOMPP MAT8 again. Is it even possible to creat such a laminate and if yes, in wich order should I assign the properties and creat the laminate?Or are there other ways to simulate this kind of sandwich structure in HyperMesh and OptiStruct? Here I uploaded the HM file so you can have a detailed look at my model: http://www.file-upload.net/download-10836303/3-point-bendingtest-setup-2.hm.html These are some screenshots of the different views on the model:By property, 2D detailed http://www.pic-upload.de/view-27981011/Forum-by_prop.png.htmlBy component, 2D detailed http://www.pic-upload.de/view-27981021/Forum-by_comp_2D.png.htmlBy component 2D traditional http://www.pic-upload.de/view-27981023/Forum-by_comp_1D.png.html I hope you get my problem and can help me fix it. Thanks in advance!