DEFINITION AND SELECTION OF THE PROPER FLEX COUPLING FOR AN EXHAUST SYSTEM Mauricio MONTEAGUDO

Transcription

1 DEFINITION AND SELECTION OF THE PROPER FLEX COUPLING FOR AN EXHAUST SYSTEM Mauricio MONTEAGUDO 4th European HTC- Versailles, France October 27-29, 2010

2 Content 1. Abstract 2. Introducing Faurecia 3. Problem Definition 4. Solution Analysis 5. Summary & Prospects for the future 2

3 Abstract Currently the Automotive industry is exposed to an enormous pressure of competition, dealing with high levels of warranty claims, due to the aggressive time-frame for the development of new products in the market as well as the inappropriate simulation and experimental use of development procedures or methods to define and select properly vehicle components or sub-components. The present document has the objective to propose a CAE (Computer Add Engineering) methodology to define and select the proper flex coupling for an Exhaust System under engine roll & road excitations. Road & Engine roll excitations are gotten from the Road Load Data Acquisition (RLDA) experimental campaign. This loads are used to design, develop and validation of exhaust system. Since the length of the exhaust flex coupling has an import role in the structural durability behavior of the complete exhaust system and their sub-components, is necessary to know the correct length before to build of prototypes for DV gate. The length of the flex couplings is deduced from the post processing of relative displacements between the inlet & outlet side of the flex coupling. Is presented a TCL scrip to speed up the relative displacements of the different lengths and compare them to select the proper one according the damage of the line. The information from the better will be provided to the Flex coupling Tier II supplier to determinate its fatigue life, and release a design more robust to be validated during experimental tests according the Durability workflow. 3

4 Introducing Faurecia 4

5 Leader in four core Business 2009 sales by Business Group No.1 in Europe 12% 35% No.3 worldwide 23% No.1 worldwide 30% No.1 worldwide 5

6 Emissions Control Technologies 13,000 employees 12 R&D centers Annual production figures: 66 plants 23 countries Complete line Manifold Catalytic converter Complete exhaust systems: 10 million units Manifolds: 3 million units Catalytic converters: 20 million units Diesel particulate filters: 3 million units Mufflers: 20 million units Diesel particulate filter Muffler 6

7 Problem Definition 7

8 CONCEPTS COLD END HOT END Flexible The main function of a flex coupling are: 1. Isolate high frequency engine vibrations 2. Reduce structure borne noise and vibrations 3. Decouple low frequency gross engine motions 4. Provide a leak free duct for the exhaust gas 5. Reduce the operating stresses and increase fatigue life of exhaust and engine system components as measured on a representative vehicle by the supplier 6. Possibly make vehicle assembly installation of the exhaust system easier where unavoidable build variations are present 8

9 COMPONENTS (BOM) Outer braid or Outer wire mesh Endcaps Bellows Interlock or Innerbraid 9

10 Engine Rock & Road load (0-20 Hz) Engine Rock excitation Flex Coupling Isolator s Road Load excitation 10

11 Engine rock angle ( ) Engine Rock & Road load (0-20 Hz) ,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1, ,5 1 1, Time [s] 11

12 Force [N] Displacement [mm] Force [N] Moment [N.m] Engine Rock & Road load (0-20 Hz) Engine Rock &Road excitation Results Displacement FLEXIBLE out 1,5 Ux_FLEX_out Uy_FLEX_out 1 Uz_FLEX_out 0, ,2 1,4 1,6 1,8 2 2,2 2,4 2,6 2,8 3 Force ISOLATORS 400 Fx_SAVD 300 Fy_SAVD Fz_SAVD ,5 2 2, M MUFFLER in 50 Mx_SILEN_in 40 My_SILEN_in 30 Mz_SILEN_in ,2 1,4 1,6 1,8 2 2,2 2,4 2,6 2, , ,5 Time [s] Time [s] -50 Time [s] Force ISOLATORS Fx_SARD Fy_SARD Fz_SARD Necessary to Change of Flex length to see impact in Bending moments 0 1 1,5 2 2, Time [s] 12

13 % RLDA results for component validation (example) Damages : Rear_Muffler_Inlet 12,00 Equivalents : Converter_Inlet [N.m] Equivalents : Converter_outlet [N.m] 10,00 9,41 10,34 9, ,00 14, ,00 18, , ,00 10,00 8,00 6,00 4, ,00 14,00 12,00 10,00 8,00 6, ,00 6,00 7,43 5,95 7, ,00 0, ,00 2,00 0, ,00 4,23 3,96 3,75 3,28 4,68 2,84 3, ,00 1,35 0,00 1,09 1,07 0,65 0,85 0,50 0,39 1,17 0,99 1,28 1,90 1,24 0,46 0,54 0,80 0, BELGIAN_BLOC_L1O_2 BELGIAN_BLOCK_HO BELGIAN_BLOCK_L1O_1 BELGIAN_BLOCK_L2O BELGIAN_BLOCK_LI BELGIAN_BLOCK_M2O BELGAIN_BLOCK_MI BELGIAN_BLOCK_SO BRAKE_MODULE CHUCK_HOLE CITY_SIMULATION COBBLE_STONE_MO_1 COBBLE_STONE_MO_2 CONCRETE_ROAD_1 CONCRETE_ROAD_2 DRVIEWAY_RAMP_13DEG DRVIEWAY_RAMP_16DEG FLAT_ROAD GEAR_BOX_MODULE GRAVEL_ROAD_SAND HIGH_G_A L_TURNS POTHOLE_1_2 SINEWAVE_ROAD_1 SINEWAVE_ROAD_2 SQUARE_TURN_MODULE STONE_ROAD TEST_HILL TWIST_ROAD WASH_BOARD_ROAD_HO Equivalents : Front_Silencer_Outlet [N.m] Equivalents : Rear_Muffler_Inlet [N.m] , , , , , , ,00 12, , , , ,00 6, ,00 4, , , , , ,

14 SOLUTION ANALYSIS 14

15 Engine Rock & Road load (0-20 Hz) Start Geometrical Flex Definition using Flex macro Data Base / OEM data 4DOF(Axial, Bending,Shering,Torsion) Mesh for mechanical analysis (structural mesh) Export equivalent beam properties results into Abaqus format Create the Very Low Frequency step cards in Abaqus format Launch VLF getting Flex relative displacements vs. Bending Moments Launch TCL scrips for n interactions Visualize the results in HyperView Re-launch this CAE workflow according Tier II Flex supplier feedback to pass acceptance criterion No Relative Displaceme nts meet target Yes Export relative displacements results into RFQ sheet format for the Flex supplier END 15

16 Faurecia scrip Length : 160 mm Flex Length Length : 220 mm Length : 180 mm 16

17 Comparison 17

18 Compare Min Max Values 18

19 SUMMARY & PROSPECTS FOR THE FUTURE 19

20 Summary & Conclusions A CAE methodology has been developed for selection of flex couplings for Exhaust Systems in Very low frequency domain (0-20Hz). An case study was presented here and proved the relative displacements approach can speed up the definition and selection of Flex coupling in the earliest virtual development stage. The compromise of decreasing hanger forces and keeping lower stress values and bending moments is possible, after getting the different flex couplings lengths. The predicted results were correlated reasonably with observed results from Faurecia decoupling elements data base assuring the steadiness of results. The present method can be also apply under Force Response Frequency (FRF) excitation. 20

21 Thank you for your attention! References Mauricio Monteagudo Galindo, Science and Technology Designing Exhaust Systems. SAE 2003 Noise & Vibration Conference, M. Monteagudo, J. Clavier, T. Lauwagie, J. Strobbe, E. Dascotte, Optimization of the Dynamic Response of a Complete Exhaust System, ISMA2008. Mauricio Monteagudo Galindo, Size Optimization process of an Exhaust System. 2nd European Hyperworks Technology Conference 2008 Strasbourg, France. OptiStruct, User s Manual, version 10. Contact Mauricio Monteagudo Galindo R&D Exhaust Durability Manager Faurecia R&D / France. Tel: +(33) mauricio.monteagudo@faurecia.com 21

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