ShockandVibration冲击与振动VIP免费

$EVWUDFWThe lecture gives an introduction to vibration through a description of themost common mechanical parameters leading to the behaviour of simplemass-spring systems. Furthermore the different types of signals and theirdescription is treated and the conversion between the different parameters isdescribed mathematically and graphically. Finally the measurement units aredefined.BA 7674-12, 1l Definitionsl What is Vibrationl Mechanical Parametersl Mass-spring Systemsl How to Quantify Vibrationl Signal Typesl Time Signal Descriptorsl Conversions:Acceleration, Velocity, Displacementl Units,QWURGXFWLRQWR6KRFN 9LEUDWLRQ/(&785(127(Copyright© 1998Brüel & Kjæ r Sound and Vibration Measurement A/SAll Rights ReservedEnglish BA 7674-12Page 2'HILQLWLRQVIt is practical to know more precisely what we are going to talk about. Thesedefinitions are adapted from the “Shock and Vibration Handbook” by Harrisand Crede (see literature list).BA 7674-12, 2'HILQLWLRQV9LEUDWLRQ is an oscillation wherein thequantity is a parameter defining themotion of a mechanical system2VFLOODWLRQ is the variation, usually withtime, of the magnitude of a quantity withrespect to a specified reference when themagnitude is alternately greater andsmaller than the referencePage 3:KDWLV9LEUDWLRQ"Vibration is mechanical oscillation about a reference position. Vibration is aneveryday phenomenon, we meet it in our homes, during transport and atwork. Vibration is often a destructive and annoying side effect of a usefulprocess, but is sometimes generated intentionally to perform a task.9LEUDWLRQRIPDFKLQHVVibration is a result of dynamic forces in machines which have moving partsand in structures which are connected to the machine. Different parts of themachine will vibrate...