Re: [Flightgear-devel] Pressure distribution calculation on planes when landing?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Andy Ross schrieb: Dai Qiang wrote: I'm wondering, if it's possible to calculate and record the pressure distribution on all parts of a plane, e.g. gears, wings etc, when it's landing? Landing gear could be done fairly easily, as the force along the gear strut is known to the FDM. But stress on other aircraft parts are basically impossible with a FDM at our level of precision: you would need a full finite-element model of every load-bearing structure on the aircraft. That's definitely not a task for a real-time simulation. Dai Qiang, for what do you need that data? I can only think of animating the model. This works already for the gear model. And an reasonable animation of the wings could be easily faked. All you need is the amount of lift they produce. Divide that with a constant weight-force of the plane (e.g. MTOW * earth acceleration) and you get a number that is zero when the wings produce no lift and 1 during a steady flight (and somewhere above 7 when the wings break...) CU, Christian . -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.0 (MingW32) iD8DBQFDjID1lhWtxOxWNFcRAp66AJ9Tnw97UCGc1Tr5gxwjtg6FLGwD3wCdEW3j TDdl2oi9/9eQGQI9Wm+Z2Ag= =Jtsq -END PGP SIGNATURE- ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Pressure distribution calculation on planes when landing?
Andy Ross schrieb: Dai Qiang wrote: I'm wondering, if it's possible to calculate and record the pressure distribution on all parts of a plane, e.g. gears, wings etc, when it's landing? [snip] Dai Qiang, for what do you need that data? I can only think of animating the model. This works already for the gear model. And an reasonable animation of the wings could be easily faked. All you need is the amount of lift they produce. Divide that with a constant weight-force of the plane (e.g. MTOW * earth acceleration) and you get a number that is zero when the wings produce no lift and 1 during a steady flight (and somewhere above 7 when the wings break...) I thought more about structural integrity and the residual weakness after the plane is abused beyond the certified envelope rather than the way it is animated when I read the original poster. ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Pressure distribution calculation on planes when landing?
--- Vassilii Khachaturov wrote: I thought more about structural integrity and the residual weakness after the plane is abused beyond the certified envelope rather than the way it is animated when I read the original poster. To go partly off topic, presumably we could use the current g force to determine when the plane goes past design limits and breaks up. From the Pilot's Handbook of Aeronautical Knowledge, the different aircraft category limits are as follows. Normal: 3.8 to -1.52 Utility: 4.4. to -1.76 Acrobatic: 6.0 to -3.0 There is a safety factor of 50% on the numbers above, but it would give us a first-pass at knowing when an aircraft breaks up due to rough handling. BTW: For those who are not aware of it, the Pilot's Handbook is a fantastic resource for flight information, and can be downloaded as a PDF from the FAA website. -Stuart ___ Yahoo! Messenger - NEW crystal clear PC to PC calling worldwide with voicemail http://uk.messenger.yahoo.com ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Pressure distribution calculation on planes when landing?
--- Christian Mayer [EMAIL PROTECTED]写道: -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Andy Ross schrieb: Dai Qiang wrote: I'm wondering, if it's possible to calculate and record the pressure distribution on all parts of a plane, e.g. gears, wings etc, when it's landing? Landing gear could be done fairly easily, as the force along the gear strut is known to the FDM. But stress on other aircraft parts are basically impossible with a FDM at our level of precision: you would need a full finite-element model of every load-bearing structure on the aircraft. That's definitely not a task for a real-time simulation. Dai Qiang, for what do you need that data? Hi Christian, I think the data would be a reference to forecast the metal fatigue situation of a plane, after it lands for several times. Just like what Vassilii said in the last post, structural integrity and the residual weakness would be brought into the whole physics model. I can only think of animating the model. This works already for the gear model. And an reasonable animation of the wings could be easily faked. All you need is the amount of lift they produce. Divide that with a constant weight-force of the plane (e.g. MTOW * earth acceleration) and you get a number that is zero when the wings produce no lift and 1 during a steady flight (and somewhere above 7 when the wings break...) CU, Christian . -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.0 (MingW32) iD8DBQFDjID1lhWtxOxWNFcRAp66AJ9Tnw97UCGc1Tr5gxwjtg6FLGwD3wCdEW3j TDdl2oi9/9eQGQI9Wm+Z2Ag= =Jtsq -END PGP SIGNATURE- ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d __ 赶快注册雅虎超大容量免费邮箱? http://cn.mail.yahoo.com ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
[Flightgear-devel] Pressure distribution calculation on planes when landing?
Hi guys, I'm wondering, if it's possible to calculate and record the pressure distribution on all parts of a plane, e.g. gears, wings etc, when it's landing? Thanks, - Qiang ___ 雅虎免费G邮箱－中国第一绝无垃圾邮件骚扰超大邮箱 http://cn.mail.yahoo.com ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Pressure distribution calculation on planes when landing?
Dai Qiang wrote: I'm wondering, if it's possible to calculate and record the pressure distribution on all parts of a plane, e.g. gears, wings etc, when it's landing? Landing gear could be done fairly easily, as the force along the gear strut is known to the FDM. But stress on other aircraft parts are basically impossible with a FDM at our level of precision: you would need a full finite-element model of every load-bearing structure on the aircraft. That's definitely not a task for a real-time simulation. Andy ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
