null » 29 null » 1 ù t null bnull Ð null Volnull 29 Nonull 1null 2008 M null null 1 ACTA AERONAUTICA ET ASTRONAUT ICA SINICA Jan. null 2008l à ° ù : 2007null01null16; © è ° ù : 2007null09null20 Á [ " :O Ú Á ( 20050501)Y ß T :I Ö £ Enullmail: jiayu hong@ buaa. edu. cnnull null Ó c I | : 1000null6893( 2008) 01null0075null05 8 O ¥ î ÿ ? _ s á Ö , I Ö £( Ø t bt ? v Ð t b S Ð Ð ý ñ Ð ý , Ø null 100083)DynamicResponseSimulationandAnalysisof LandingGearwith FlexibleFuselageLiao Lijuan, Jia Yuhong( School of Aeronautic Science and Engineering, Beijing U niversit y of Aeronautics and Astronautics,Beijingnull 100083, China)K null 1 : Y V y ë 8 ¥ © r , " d ¥ î ± s Z ñ ;i ADAM S/ Aircraft Ì â Ï y ë ´ E " ,_ µ 8 ¥ f " d H ¥ î ÿ Y b_ ² T A U 8 ? l { Û ? ¥ T ¨ , l Ï ÿ ¥ 6null 5% ,i V [ a h ^ " d H ¥ § Á V b I n 8 O " d É ù î s ,¤ 8 ¥ ® ¨ ÿ 4 Ú f O Ï r q ¥ T ¨ b¾ ! 9 Z E ? h l } ø Ï ¥ s ,ü É O p bN , . d O Ï ! 9 5 É ÿ b1 o M : 8 ; O ; © r ; ´ E " ; î ÿ Y Ï m s Ë | : V214null 13 null null null Ó D S M : AAbstract: The dynamics differential equat ions of the airplane syst em w ith flexible fuselage are deduced based onthe establishment of equivalent model. An aircraft model w ith f lexible fuselage using virtual protot ype is apnullplied based on the mathematical models of the whole system in ADAM S/ Aircraft version. A series of simulanulltions of dynam ics responses are analyzed. Simulat ion results show the importance of considering t he influenceof flexible body in the design of landing gear. Flexible fuselage is able to contribute to absorbing 6null 5% energyof shock absorber and alleviat ing overload during landing appropriately. It plays a role in absorbing and dissinullpation energy. Via research and analysis of the landing gear system with flexible body, the conclusion is gotthat t he efficiency of shock absorber depends on t he low order elastic modes to a great extent. Decreasing theburdens on tires and shock absorber, and ut ilizing the influence of flexible fuselage prolongs the life of landinggear. It perfects the design criteria of shock absorber commonly used.Keywords: f lexible fuselage; landing gear; equivalent model; virtual protot ype; dynamic responsenull null v f Ü ¹ ë Ú Î Á ¥ î $ª ¹ ^ / î f 8 O ²  ¸ å Ê # îÿ ï ¥ B ñ × 1 y Í [ 1null4] b¿ É O ¥ ? , ' É ^ ¿ ÿ Ï "d î ¥ l ? ï b. d ¥ O Ï " d ! 9 , [ l " d ÿ ¹ 5 b ® f 8 O " d Á 3 ¥ Y Ã Í I n bÛ " C } v f ¥ ? Z ,+ Y ^ v Z ? 1 f ,Ç Ç G L . d ! 9 Z E ? r f Ï "d ¥ K ª ý T ÿ [ 5null8] b' Ó y ë µ ¥ f 8 [ # 8 Ð Ï õ ¤ b N $ , ADnullAM S/ Aircraft Ï y ë ´ E " ,ç Q & Ï ¥ Y , ¹ É B ¿ É O ! 9 4 I [ 9null11] b1null " d Ð I n 8 f O Ï ¥ Y ,y ë I n 8 ® ¨ î ÿ ¥ 8 [ 1 ] , ¨ ¥ U S "  m 1î U b 8 Ç V [ l ? , Î V [ { Û "d ? , Ï µ 8 í q aë ¯ í q ED í q [ 12null20] , î y ë ¥  m 2î U bm Ï : P¹ O Ï ï < _ s ; mc ¹ Ð O Ï õ ¤ ¥ © r É v ¥ É ; L c ¹ © r É vmc ¥ © r 6 ï ; mbi(i= 1, 2, null, n)¹ õ ¤ © r É v mc ¥ Q 8 ¥ © r É v ¥ É , Ê Â Ê ¿ P ª : L bi¹ T ¨ ¿ © r É v m bi¥ © r 6 ï ; K bi¹ © r È ; Cbi¹ © r E Dnull null t null bnull Ð null » 29 " ; yc, ybis Y ¹ © r É v m c mbi¥ < _Ê M M Ä bm 1null " d U S "Fignull 1 null Coordinat e syst emm 2 null f 8 © r Fignull 2null Equivalent model of flexible fuselage5 8 © r " d ¥ î ï Ð Z ñ ¹mbi y bi = - K bi( ybi - yc) - Cbi(nully bi - nully c) -L bi + mb ig (1)mc yc = !ni= 1K bi(ybi - yc) + !ni= 1Cbi(nully bi - nullyc) -P - L c + mcg (2)null null | m 2î U ¥ ç l ¹ 8 v ,5 " d V ñ f ¥ © r  m 3î U bm 3 null f " d H ¥ © r Fignull 3 null Equivalent model of landingm Ï : mt ¹ O d ¦ ê É , Ï Ö c a ë Ú Â a} ø Ú O © d b Þ¦ ê É ; Pt ¹ } ø ï ; y。