Modeling and Analysis of a High Performance Engine Cranktrain

Transcription

1 Modeling and Analysis of a High Performance Engine Cranktrain Michele CALABRETTA Automobili Lamborghini, S.p.A. Peter NGUYEN Gamma Technologies, Inc.

2 Correlation to Lamborghini Bearing Tool Bearing Orbit Bearing Load Map Failure Criteria Correlation to Lamborghini Torsional Vibration Tool Lightweight Crankshaft Study Development of GT-SUITE 3D-Beam Model FEA inputs Correlation to rigid bearing results Correlation to torsional results Fast GT-SUITE analysis of counterweight under-balance

3 Bearing Orbit Correlation Peak Power RPM Lamborghini Tool GT-SUITE

4 Bearing Load Correlation Peak Torque RPM Lamborghini Tool GT-SUITE

5 Bearing Failure Criteria Correlation

6 Correlation to Lamborghini Bearing Tool Bearing Orbit Bearing Load Map Failure Criteria Correlation to Lamborghini Torsional Vibration Tool Lightweight Crankshaft Study Development of GT-SUITE 3D-Beam Model FEA inputs Correlation to rigid bearing results Correlation to torsional results Fast GT-SUITE analysis of counterweight under-balance

7 Torsional Vibration Correlation Calculated crank nose torsional vibrations (red lines) plotted on the experimental measured signal shows good correlation.

8 Lightweight Crankshaft Study Crankshaft Geometry Modified in CAD/FEM Reduced Stiffness, Lower Eigenfrequencies Torsional vibration most severe in Journal 3 but only over overspeed condition

9 Lightweight Crankshaft Study Significant excitation of the 2 nd Eigenfrequency.

10 Correlation to Lamborghini Bearing Tool Bearing Orbit Bearing Load Map Failure Criteria Correlation to Lamborghini Torsional Vibration Tool Lightweight Crankshaft Study Development of GT-SUITE 3D-Beam Dynamic Model FEA inputs Correlation to rigid bearing results Correlation to torsional results Fast GT-SUITE analysis of counterweight under-balance

11 Construction of Beams 2, 3, or 4-noded Beam FE primitives are used to model different crankshaft components such as Journals, Crankwebs and Crankpins. Elements Nodes

12 Bending Stiffness Analysis

13 Animation of the deformed crankshaft

14 Validation of Dynamic Beam Model Energy decaying scheme for non-linear beam models Bauchau, O.A. and Theron, N.J. Computer Methods in Applied Mechanics and Engineering. Vol. 134, no. 1-2, pp

15 Typical Bearing Result Rigid vs. Dynamic

16 Bearing Failure Criteria Rigid vs. Dynamic

17 Correlation of Pure Torsion and Dynamic Bending Low RPM

18 -Possible combination of bending and torsional modes Correlation of Pure Torsion and Dynamic Bending High RPM

19 Additional Vibration Modes present in Dynamic Bending

20 Correlation to Lamborghini Bearing Tool Bearing Orbit Bearing Load Map Failure Criteria Correlation to Lamborghini Torsional Vibration Tool Lightweight Crankshaft Study Development of GT-SUITE 3D-Beam Dynamic Model FEA inputs Correlation to rigid bearing results Correlation to torsional results Fast GT-SUITE analysis of counterweight under-balance

21 Current crankshaft design is overbalanced From classical engine theory, overbalance allows for lower peak bearing forces Axial crank-slider reciprocating forces reduced Some tangent centrifugal forces added Optimization of counterweight size allows lower crankshaft inertia and mass Faster engine response *Norton, Robert L. "Balancing the Single Cylinder Engine." Design of Machinery: an Introduction to the Synthesis and Analysis of Mechanisms and Machines. 2nd ed. Boston, MA: McGraw Hill, Print.

22 Effect of Counterweight Reduction Minimum Oil Film Thickness Peak Oil Film Pressure

23 Future Collaboration Work Combined stress analysis from Dynamic model Development of reduced finite element model in GT- SUITE v7.1 Thank you to primary contact at Lamborghini, Dr. Michele CALABRETTA