Question #671364 on Yade changed: https://answers.launchpad.net/yade/+question/671364
jacopo gave more information on the question: let me know if you can see the file i sent you. thanks jan. ________________________________ Da: Jacopo Varriale Inviato: sabato 18 agosto 2018 21:41:59 A: [email protected] Oggetto: Re: [Question #671364]: aircraft crash test hi jan, really thanks for the answer. The aircraft will crash only with the first part of the fusolage and will penetrate around 1/2 meters inside a soil ( it is built with 18000 spheres body). the crash test should last few seconds. The aircraft will have constant velocity (18 m/s) untill it touches the soil. As i said i don't have to be focused on deformations but i need to register the acceleration of center of gravity of the aircraft. If i understand , as you suggest me, is better if i consider the aircraft as a rigid body ( so i will not see deformations, is it exacly?), and after this, try to implement a new facet_facet contact in way to be able to see this kind of deformations. Is it right? ->""""""""How much time you have for this project? I think it is a critical point. If years, you can try a lot of things, if weeks or months, I would not be very optimistic.. Also the computational power you have might be important.."""""""" i have few months. The computational time is not a problem becouse i can use a high RAM and CPU computer power (it is a university computer). ->>""""""""" Or, if Is The same, clumping The structure. What do you suggest) . clumping the facets would make it rigid body My suggestion: I would go step by step. First make the aircraft rigid and simulate the test this much simplified. It might happen that the simulation would take too much time or the soil would react in completely different way you want or........ After you check the simulation is feasible and gives somehow acceptable results, you can make it more complicated.""""""""""" do you suggest me to clump the facets? in this way i will have a rigid body. Do i have to use sphere-facet contact only ? Becouse honestly i don't even know how to start to implement a facet-facet contact. I added the STL-file. ________________________________ Da: [email protected] <[email protected]> per conto di Jan Stránský <[email protected]> Inviato: martedì 14 agosto 2018 08:27:53 A: Jacopo Varriale Oggetto: Re: [Question #671364]: aircraft crash test Your question #671364 on Yade changed: https://answers.launchpad.net/yade/+question/671364 Status: Open => Answered Jan Stránský proposed the following answer: Hello, Instant replay: "Please describe more the experiment (how much is the aircraft crashed etc.)". First you (and we if you want our help) should know what is simulated. I know you wrote 18 m/S velocity and penetrate 1/2 meters, but for not at all experienced person it does not tell much.. > I have To use yade for this project And compare its result with others taken with others software. ok, makes some sense. Yade **might** (depending on time, dimensions etc.) be a good choice for the soil modeling, but currently definitely not for modeling deformations (especially inelastic) of the aircraft .. What exactly "its result" should be? How much time you have for this project? I think it is a critical point. If years, you can try a lot of things, if weeks or months, I would not be very optimistic.. Also the computational power you have might be important.. > I would like to see on video the deformations of the aircraft( if something > break, like The wings And etc.), that S why i would like To have facet facet > contacts. > However i don t have To register the deformation , But i would like To see > that the aircraft Is taking "damage" during the impact a few points: - according to Wikipedia (I don't know STL almost at all): "STL files describe only the surface geometry of a three-dimensional object". This would mean, that even you have facets, they are useless for aircraft modeling even if there would be fatet-facet contact (because it is "surface of surface"). Maybe you could post the stl file on the internet such that we can view it? - I understand the idea to use facets for modeling the aircraft as a shell. However, you would need some fancy cohesive inelastic facet-facet contact model able to capture shell-like behavior etc... quite a lot of work, implementing, testing.. - all in all, this aircraft modeling you want is not suitable for DEM and Yade.. - To realistically model the crash is complicated even for specialized softwares. I.e., to "see" deformations and damage is no problem, but if you come to velocity, energies... Maybe you could model the airplane also by spheres, but that would need a lot of preprocessing work.. > Or, if Is The same, clumping The structure. What do you suggest) . clumping the facets would make it rigid body My suggestion: I would go step by step. First make the aircraft rigid and simulate the test this much simplified. It might happen that the simulation would take too much time or the soil would react in completely different way you want or........ After you check the simulation is feasible and gives somehow acceptable results, you can make it more complicated. cheers Jan -- If this answers your question, please go to the following page to let us know that it is solved: https://answers.launchpad.net/yade/+question/671364/+confirm?answer_id=4 If you still need help, you can reply to this email or go to the following page to enter your feedback: https://answers.launchpad.net/yade/+question/671364 You received this question notification because you asked the question. -- You received this question notification because your team yade-users is an answer contact for Yade. _______________________________________________ Mailing list: https://launchpad.net/~yade-users Post to : [email protected] Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
