High accuracy machines on factory floors
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Missie en Visie TU Delft
High accuracy machines on factory floorsAnthonie Boogaard#Challenge the futureWhat are high accuracy machines?
Photolithographic toolsHealthcare machinesLarge printers#Challenge the futureWhat is the problem?Electronic products getting smallerProduction technique of desktop processors by Intel3 m in 197832 nm in 2010Disturbances from the floorDynamic couplingFloor vibrations
#Challenge the futureResearch topicsInvestigate the dynamic behavior of factory floors and propose a method to properly predict the dynamic coupling between the machine and the floor it is placed on.
Develop a method to predict the new vibration level of the floor, based on the dynamic response and the free vibration level.#Challenge the futurePresentation outlineIntroductionExisting methods for floor disturbancesFrequency Based SubstructuringGround Vibration TransmissionExperimental validationResultsComparisonConclusion and recommendationsQuestions
#Challenge the futureExisting methodsDynamic coupling
FixedSimpleOnly true for infinitely stiff floorsFloor stiffnessMore advancedResemblance of reality?SDOF floorAdvancedNeeds more information about the floor#Challenge the futureExisting methodsFloor vibrations
Directly on the mountsSimpleOnly true for infinitely stiff floorsOn the fixed worldTakes floor stiffness into accountMore realistic?#Challenge the futureFrequency Based Substructuring
floorCompatibilityEquilibrium#Challenge the futureFrequency Based SubstructuringDynamic equilibrium of the machine:
Interface forces defined with Lagrange multiplier
Dynamic flexibility#Challenge the futureFrequency Based SubstructuringSummarizing:
Solving this set of equations and neglecting the applied forces on the floor yields
#Challenge the future10Frequency Based SubstructuringDynamic flexibilityFor the machineFull matrix is needed, as if it is floating freeCan be easily obtained from the modelFor the floorCan be obtained from a model of the buildingDifficult to model a building accuratelyOnly interface flexibility is neededSolution: dynamic measurements#Challenge the futureGround vibration transmission
floor#Challenge the futureExperimental validationTest case model
Coupling with rotationsCoupling with translations#Challenge the futureExperimental validationTest case construction
#Challenge the futureExperimental validationMeasurementsFloor measurementImpact measurement on a flexible floorTest case measurement on a very stiff floorAssume fixed responseObtain free description from fixed measurementValidation measurementTest case measurement on the flexible floor of step 1
#Challenge the futureFloor measurement
#Challenge the futureExperimental resultsCoupling
#Challenge the futureExperimental validationVibration measurementMeasure vibration level of the flexible floor with and without test case.Shaker with a small mass to provide equal excitations for both measurementsShaker excitation: 12 and 16 Hz
floor#Challenge the futureExperimental resultsGround vibration transmission
#Challenge the futureComparison coupled responseRecap
FixedFloor stiffnessSDOF floor
#Challenge the futureComparison coupled response Fixed and floor stiffness
#Challenge the futureComparison coupled response Fixed and SDOF floor
#Challenge the futureComparison coupled response SDOF floor measurement
#Challenge the futureComparison floor vibrations Vibrations of the tool
#Challenge the futureWhen should this method be applied?
#Challenge the futureConclusionsIt is possible to predict the coupled response of a machine using the FBS technique and dynamic floor measurements.Single driving point coupling is a very good approximationSimple SDOF floor is a good approximation.Assuming a linearized floor stiffness is not always a good approximationIn most cases it is no better approximation than assuming an infinitely stiff floor.Ground vibration transmission technique was not validated.
#Challenge the futureRecommendationsAlways use the FBS method for floors with a low eigenfrequency, or when the mounting stiffness is equal to the floor stiffness.Specify a floor stiffness and a fundamental frequency for the floor, to ensure proper operation of the machine.Build a database with floor measurements.Perform a model study with typical machinery.Validate ground vibration transmission technique on a much simpler test case.Design a test case where one has more control over the test conditions.#Challenge the futureThank you
#Challenge the future