Post on 28-Mar-2018
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Jean-Claude Luneno, PhDDynamics of Rotating Machines
Modeling the torsional dynamics of reciprocating machines: “Pitfalls and Challenges”
ÅF-Sound & Vibrations
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MITT I CENTRALA BORÅSCitycampus - plats för möten
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CRANK SHAFTS
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TORSIONAL ANALYSIS: Modeling
Lumped-parameters model:Moment of inertia per cylinder lineincludes contributions fromreciprocating and rotating parts at thecorresponding cylinder position.
Rotating parts: Crank pin, crank web,balance weight, connecting rod (lowerpart)
Recip parts: Piston, connecting rod(higher part)
Handbooks provide expressions to evaluatethese concentrated moments of inertia for well-defined crankshaft geometries
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Crankthrow equivalent stiffness (Ke):Observe that the crankpin is twisted while thecrankweb is bended (Analytical method)
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Inclusion of journal inertia and stiffness (FE modeling)
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Hybrid model: Lumped and descretized system“Case Example modelled in DyRoBeS”
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Typical reported Data for torsion analysis
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CASE1: GIVEN ”JP 4 CYLINDERS”
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Reported results
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CASE1: GIVEN ”JP 4 CYLINDERS”
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CASE1: GIVEN ”JP 4 CYLINDERS”
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CASE1: GIVEN ”JP 4 CYLINDERS”
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CASE2: GIVEN ”RECIP MASS”
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CASE2: GIVEN ”RECIP MASS”
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CASE2: GIVEN ”RECIP MASS”
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CASE2: GIVEN ”RECIP MASS”
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HB has started partnership with AVL (Excite & Fire)
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AVL excite + Ansys/Abaqus: Stress analysis