Bmbardier Inc. u ses filiales. Tus drits réservés. BOMBARDIER THOUGHTS FAA Bmbardier Wrkshp Mntreal 15-18 th September 2015
Bmbardier Inc. u ses filiales. Tus drits réservés. LEVERAGING ANALYSIS METHODS As the knwledge base increases thrugh test validated analytical slutins, ptential fr increased efficiency f subsequent test validatins increases. The efficiency shuld nt be nly bserved thrugh natural tendency t reduce direct cst by reducing the number f test specimens, but als as verall efficiency f certificatin prcess resulting frm increased ability t recgnize critical failure mdes in a given structure. As we g thrugh certificatin prcess, acceptable level f safety becmes mre and mre recgnizable which ultimately becmes the basis fr the ptimizatin f subsequent testing prgrams. Relevant field experience shuld als be cnsidered. We shuld pssibly think f applicability t large (full-scale) sub-cmpnents and full scale aircraft cmpnents where validatin is required and where failure mdes and their interactins can be relatively easily recgnized n the basis f previus (validated) experience fr a given design space. Optimizing testing prgram at cupn level (allwable) is nt necessarily an bjective unless equivalency f engineering space can be demnstrated 2 FAA/Bmbardier/TCCA/EASA Wrkshp, Mntreal, September 15-18, 2015
Bmbardier Inc. u ses filiales. Tus drits réservés. LEVERAGING ANALYSIS METHODS Essentially analysis drives the selectin f test articles in terms f lading (mechanical and thermal), cmplexity and nvelty f design features, recgnized failure mdes, anticipated utilizatin, hybrid structure cnsideratins etc. One culd think f the prcess as addressing design features that were nt part f previusly interrgated design space. Analysis can als be used t establish cmpatibility f the new design with previus (referenced) designs in rder t ptimize test prgram fr the new design. It is cnsidered critical t establish bundaries (limitatins) f analytical slutins (cnfiguratin, design space, envirnmental and accidental threats, anticipated utilizatin etc. Leveraging analysis wuld ultimately mean utilizatin f previusly test validated analytical methds in rder t ptimize test interrgatins (number and cmplexity) fr new designs that are fund t be similar in critical design features t previusly certified prducts 3 FAA/Bmbardier/TCCA/EASA Wrkshp, Mntreal, September 15-18, 2015
Bmbardier Inc. u ses filiales. Tus drits réservés. TESTING OPTIMIZATION Increased reliance n analytical evaluatins t guide test specimen selectin and prtcls, pssibly invlving details, large sub-cmpnents and full scale cmpnents (analysis used t search fr critical failure mdes). Increased reliance n pre-prductin test articles (demnstratrs) as ppse t cmplete aircraft and think f cmplementing gaps (near prductin cnfiguratin) by sub-cmpnents and details which may be due t alteratin f critical manufacturing prcess parameters). The apprach allws fr mre timely (als less risky) structural interrgatins given that static strength interrgatins are adequately addressed after fatigue cycling. Optimizing testing prgram by breaking dwn majr structural cmpnents int typical and representative elements (i.e. typical fuselage segment, wing, etc.) ffers ptential fr early interrgatins f simpler articles Ratinalizing t a single full scale test cmpnent (cycling + static) 4 FAA/Bmbardier/TCCA/EASA Wrkshp, Mntreal, September 15-18, 2015
Bmbardier Inc. u ses filiales. Tus drits réservés. UNIQUE ISSUES/CHALLENGES One f the majr challenges remain hybrid structure test interrgatins including envirnmental effects. Incmpatibility f fatigue lading spectra relative t different sensitivity t lad magnitude between cmpsite and metals Applicatin f Lad Enhancement Factrs (LEF) in fatigue interrgatins ptentially triggers premature cracking in metallic structure Envirnmental Cmpensatin Lad Factrs (ECLF) in static strength interrgatins Difficulty in adequate thermal lading applicatins and ability t cmpensate fr temperature via mechanical lading (in mst cases nt representative) as the mechanical lads are balanced differently cmpared t thermal. Nearly adjacent structural detail may be critical fr different envirnmental cnditins Thru-thickness temperature gradients (i.e. fuel tank) Upper and lwer surfaces culd be at significantly different thermal state (i.e. wing, hrizntal stabilizer etc.) fr the same aircraft thermal cnditin Sme structural elements are driven by the internally generated heat (i.e. effects f systems).. 5
Bmbardier Inc. u ses filiales. Tus drits réservés. UNIQUE ISSUES/CHALLENGES Sme challenges in full scale sub-cmpnent thermalmechanical test interrgatins: Bundary effects reduce zne f test interrgatin Cycling at cnstant, analytically evaluated critical temperature, further narrws dwn interrgatin zne fcus n particular critical thermal/mechanical lad cmbinatins Cmplex analysis and cupn testing required t validate zne f interest Difficulty t cntrl envirnment cstly thermal chambers Residual Strength (after cycling) at critical temperature smewhat less cmplex Variable thermal state f stress in fuselage Lcal Effect f system generated heat Wing upper and lwer surface experiences different thermal cnditins 6 FAA/Bmbardier/TCCA/EASA Wrkshp, Mntreal, September 15-18, 2015
Bmbardier Inc. u ses filiales. Tus drits réservés. REGULATORY ACCEPTANCE Reliance n previusly test validated analytical slutins fr which bundaries f applicability are well established Leveraging analytical methds can be t a pint based n principles fr derivative mdels 7