文档介绍：RandomRandom VibrationVibration SolutionsSolutions
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RandomRandom VibrationVibration
ANSYSANSYS WorkbenchWorkbench v11v11
StephenStephen ScampoliScampoli
TechnicalTechnical SolutionsSolutions SpecialistSpecialist
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WebExWebEx AgendaAgenda
• Random Vibration Overview
– PSD Analysis
– Applications
• Workbench Capabilities
– Loading
– Solution
– Postprocessing
– Workflow Overview
• Demonstration
• Conclusions
• Questions & Answers
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RandomRandom VibrationVibration
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WhatWhat isis RandomRandom Vibration?Vibration?
• Determines the response of a structure to
vibration loads that are random in nature.
• Intended loads for that produce different time
histories during every loading.
Reference: Random vibrations in mechanical systems by Crandall & Mark
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What is Random Vibration?
• Transient analysis is not an option since the time
history is not deterministic.
• Instead, the sample time histories are converted to
Power Spectral Density function (PSD), a statistical
representation of the load time history.
Image from “Random Vibrations Theory and Practice” by Wirsching, Paez and Ortiz.
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What is a PSD?
• A PSD records the mean square value of the
excitation and response as a f