Structural Analysis Department (D²S) DCNS research

Transcription

1 Structural Analysis Department (D²S) DCNS research A team f R&D engineers geared tward researches in naval shipbuilding DCNS research is the Research and Technlgical Centre f the French naval shipbuilder DCNS, Fig. 0. Within DCNS Research the Structural Analysis Department (D²S) is a cntributr in the develpment and the validatin f numerical methds fr the simulatin f fluid-structure interactin prblems, with applicatins t naval shipbuilding. Gathering 5 R&D Engineers with different fields f expertise, and cmplemented with 5 PhD Students, the team is invlved in varius scientific cllabratins ; it aims at bridging the gap between fundamental research in the field f cmputatinal mechanics and industrial applicatins f innvative numerical methds fr ship design. It is active within a netwrk f experts and scientists riginating frm Industry (eg. BUREAU VERITAS, CEA, CNIM, EDF, STX) r Academia (eg. CNRS, ENSTA Paris, ENSTA Bretagne, Université de la Rchelle, Université de Nantes, Ecle Centrale de Nantes, INSA Lyn, IReNav), as well as frm guvernemental agencies (eg. Office f Naval Research, Centre Natinal de la Recherche Scientifique, Délégatin Générale pur l Armement), Prfessinal Assciatins (eg. Assciatin Française de Mécanique, American Sciety f Mechanical Engineers) r numerical cde develpers and editrs (eg. ANSYS, CD-ADAPCO, EDF R&D, SIMULIA). Engineers frm the D²S team are als majr cntributrs in cllabrative R&D prjects in the cntext f reginal r natinal initiatives, such as IRT Jules VERNE in Pays de la Lire. Fig. 0 DCNS Research is the R&T Centrer f French Naval shipbuilder DCNS. It is a unique structure which hsts sme 125 experts, engineers, researchers and PhD students. DCNS ffers a wide range f slutins, frm R&T studies (such as thse presented in the paper) t services (such as testing, nn destructive cntrls and expertise) and prducts (such as submarine aut-pilts and unmanned surface vehicles).

2 The team has cnducted researches with mre than 15 PhD students ver the past ten years and has cntributed t the publicatin f sme 45 papers in scientific jurnals and 65 cmmunicatins in natinal and internatinal cnferences. Members f the team are R&D engineers with a high level f technical and scientific skills. Brun LEBLE is an expert in numerical techniques fr strngly nn-linear prblems, with an emphasis n underwater explsins, nn-linear behaviur f materials and systems; he is als the technical manager f R&D prgrams. Cédric LEBLOND, PhD, develps mathematical mdels applied t fluid-structure interactin, mainly based n reduced-rder-mdelling and lw rank apprximatins (using such techniques as Prper Generalised Decmpsitin). Flrent BRIDIER, PhD, investigates numerical techniques fr slving multi-physic prblems, including the numerical simulatin f welding, in rder t assess the lifetime issues f marine structures. Rmain FARGERE, PhD, develps numerical tls t assess the dynamic behaviur f varius mechanical systems, with fluid-structure interactin mdelling (fr instance fr jurnal bearings). Jean-Françis SIGRIST, PhD, is the head f the D²S team; he c-supervises researches perfrmed by PhD students within the team; he is als the technical manager f cllabrative prjects. Researches in fluid-structure interactin mdelling Fluid-structure interactin is related t the dynamic behaviur f structures cupled t a fluid and therefre stands as majr cncern in naval shipbuilding. Cntributin f the D²S team in the develpment f numerical methds aims at tackling the variety f situatins f engineering relevance in shipbuilding, amng which the fllwing. Vibracustics The team is invlved in the develpment f finite-element based methd t accunt fr the vibracustic behaviur f cmplex immersed structures. Cmplexity may stem frm gemetry and design, fr instance with multi-material structures (cmbining cmpsites and metallic subparts, r material with visc-elastic prperties). Reduced-rder mdelling are develped and investigated; the prpsed numerical strategies allws fr a drastic reductin in cmputatinal cst, while embedding the cmplex physics at stake. Such strategies pave way fr uncertainty management and ptimisatin-riented design. (a) Finite element mdel f a cmplex immersed structure (b) Cmputatin f frequency respnse with parameter variability Fig. 1 Frm 2012 and n, a dedicated algrithm has been develped t cmpute the frequency respnse f immersed structures cmpsed f multi-materials. The algrithm is shwn t be accurate ver an extended frequency range. It is besides designed in rder t take int accunt the variability f varius

3 material prperties, thus prviding a set f data needed fr an ptimal design. Its numerical efficiency is als underlined: data prduced by the prpsed algrithm in ne calculatin wuld require sme millin calculatins with a classical finite element reslutin, being ut f reach with existing cmputer resurces. Hydrdynamics Researches in the fields f hydrdynamics and fluid-structure interactin aim at taking int accunt the influence f structural defrmatins n the hydrdynamic perfrmances f prpellers (fr instance in terms f efficiency, r cavitatin inceptin), by cmbining bth experimental and numerical appraches. Numerical techniques based n c-simulatin strategies are develped in rder t describe detailed physics, such as invlved in the vibratin/cavitatin cupling mechanisms. Such methdlgy is nw made available t mechanical engineers fr the ptimisatin f hydrdynamic prfiles. (a) Fluid flw arund a defrmable hydrfil in cavitating cnditin (experimental and numerical) (b) Hydrdynamic perfrmance f a defrmable prpeller Fig. 2 Frm 2006 t 2014, numerical strategies based n cupling structural and fluid cdes have been extensively investigated and validated n varius cnfiguratins. Influence f fluid-structure interactin n the hydrdynamic perfrmance f lifting prfiles in cavitating/nn-cavitating cnditins has been evidenced. The numerical methds are nw accessible fr large industrial applicatins in prpulsin, sea-keeping r energy harvesting. Safety assessment Mdelling fluid-structure interactins allws fr a mre detailed physics t be accunted fr in the simulatins f the dynamics behaviur f critical systems. In sme cases, fr instance when structures are subjected t severe lading cnditins (eg. impact n water, respnse t underwater explsins), a t crude simplificatin f the physics at stake might lead t misleading results which are nt acceptable when safety is at stake. Simulatins embedding a mre detailed physics allw fr a mre accurate descriptin f the system behaviur, thus guaranteeing accuracy f the calculatin.

4 (a) Impact f ship bw n water ( slamming ) (b) Respnse f a submerged cylindrical shell t an underwater explsin Fig. 3 Frm 2005 t 2011, dedicated numerical methds have been develped and applied t tackle the physics at stake in the case f impact n water f a ship bw (a) r the stress-state f a submerged shell subjected t an underwater explsin (b). In bth examples, the simulatin strategy is a unique cmbinatin f numerical and semi-analytical methds aimed at enhancing the physical accuracy f the simulatins. Frm R&T t industrial applicatins These researches are geared tward industrial applicatins; t name but a few, they are f engineering relevance in the fllwing instances: safety f critical installatins (such a cmpact nuclear prpulsin reactr in exceptinal cnditins) [2]; ptimisatin f marine energy harvesting devices, such as tidal turbines r thermal energy, Fig. 4; reductin f nise radiated by structures, at glbal (eg. a ship) r lcal scale (eg. a prpeller), Fig. 4; cntrl f structural vibratins, such as shaft lines and geared transmissin; durability f structures in marine envirnment, such as lifting devices. The researches have cntributed t enhance the design prcess f cmplex naval structures since sme f the prpsed innvatins in cmputatinal mechanics have been implemented in the numerical tls made available t the practitiner.

5 (a) Finite element mdel f a surface ship at full scale (b) Finite vlume mdel f a tidal turbine Fig. 4 The industrial applicatins f the researches in finite element-based methds cver a wide range in naval shipbuilding. Over the past years, the calculatins perfrmed within the design prcess f naval structures have benefited frm researches in fluid-structure interactin mdelling. As a result, a better understanding f cmplex phenmena is accessible t the practitiner, resulting in ptimisatin f structures and enhancement f their perfrmances. Selected references J.F. SIGRIST, S. GARREAU. Dynamic Analysis f Fluid-Structure Interactin Prblems with Spectral Methd Using Pressure-Based Finite Elements. Finite Element Analysis in Design, 43, , J.F. SIGRIST, D. BROC. Fluid-Structure Interactin Mdeling fr the Mdal Analysis f a Steam Generatr Tube Bundle. Jurnal f Pressure Vessel Technlgy, Paper n , 131, A. DUCOIN, F. DENISET, J.A. ASTOLFI, J.F. SIGRIST. An Experimental and Numerial Investigatin f Flw Over a Hydrfil in Transient Pitching Mtin. Eurpean Jurnal f Mechanics. B/Fluids, 28, , C. LEBLOND, J.F. SIGRIST. A Versatile Apprach t the Study f Submerged Tw-Dimensinnal Thin Shell Transient Respnse. Jurnal f Sund and Vibratin, 329, 56-71, A. TASSIN, N. JACQUES, A. NÊME, A. EL MALKI ALAOUI, B. LEBLÉ, Assessment and Cmparisn f Several Analytical Mdels f Water Impact, The Internatinal Jurnal f Multiphysics, 4, , A. DUCOIN, F. DENISET, J.A. ASTOLFI, J.F. SIGRIST. Numerical and Experimental Investigatin f Hydrdynamics Characteristics f Defrmable Fils. Jurnal f Ship Research, 53, , L. ROULEAU, J.F. DEÜ, A. LEGAY, J.F. SIGRIST. Vibr-Acustic Study f a Viscelastic Sandwich Ring Immersed in Water. Jurnal f Sund and Vibratin, 331, , A. DUCOIN, J.A. ASTOLFI, J.F. SIGRIST. An Experimental Analysis f Fluid-Structure Interactin n a Flexible Hydrfil in Varius Flw Regimes Including Cavitating Flw. Eurpean Jurnal f Mechanics. B/Fluids, 36, 63-74, A. TASSIN, N. JACQUES, A. NEME, A. EL MALKI ALAOUI, B. LEBLE. Hydrdynamic lads during water impact f three-dimensinal slids: Mdelling and experiments, Jurnal f Fluids and Structures, 28, , S. IAKOVLEV, C. SEATON, J.F. SIGRIST. Submerged Cylindrical Shell Subjected t Tw Cnsecutive Shck Waves: Resnance-like Phenmena. Jurnal f Fluids and Structures, 42, 70-87, J.F. SIGRIST, D. BROC. Mdelling Inertial Effects in Peridic Fluid-Structure Systems with an Hmgenisatin Apprach: Applicatin Seismic Analysis f Tube Bundles. Jurnal f Fluids and Structures, 49, 73-90, 2014.

6 S. IAKOVLEV, J.F. SIGRIST, C. LEBLOND, H. SANTOS, C. T. SEATON, K. WILLISTON. Efficient Semi-Analytical Methlgy fr the Pre-Design Analysis f the Shck respnse f Marine Structure. Offshre and Arctic Engineering, Nantes, 9-14 June F. GAUGAIN, A. ASTOLFI, J.F. SIGRIST, F. DENISET. Numerical and Experimental Study f the Hydrelastic Behaviur f an Hydrfil. Flw Induced Vibratin, Dublin, 2-6 July R. FARGERE, P. VELEX. Influcence f Clerances and Thermal Effect n the Dynamic Behaviur f Gear- Hydrdynamic Jurnal Bearing Systems. Jurnal f Vibratin and Acustics, Paper n , 135, M. CHEVREUIL C. LEBLOND, A. NOUY, J.F. SIGRIST. Mdel Reductin Methd fr the Cmputatin f a Lw- Frequency Randm Vibracustic Respnse, 11 th Wrld Cngress n Cmputatinal Mechanics, Barcelna, July 20-25, E. VERON, J.F. SIGRIST, D. BROC. Implementatin f a Stuctural-Acustic Hmgenized Methd fr the Dynamic Analysis f a Tube Bundle with Fluid-Structure Interactin Mdeling within ABAQUS: Frmulatin and Applicatins. Pressure Vessel and Piping, Anaheim, July C. LEBLOND, J.F. SIGRIST. Parametric Reduced Order Mdeling fr the Lw Frequency Respnse f Submerged Viscelastic Structures. Internatinal Jurnal fr Numerical Methds in Engineering (submitted fr publicatin). A. TALLET, C. LEBLOND, C. ALLERY. POD-based Reduced Order Mdels fr the Quasi Real-Time Optimal Cntrl f Incmpressible flws. Jurnal f Cmputatinal Physics (submitted fr publicatin)