A multi-purpose vibration experiment using labview

Abstract

The response of an aluminum cantilever beam under harmonic excitation is simultaneously measured using a strain gage, a linear variable differential transformer and an accelerometer, and compared with the real time theoretical response. All data acquisition and analysis is done using a custom built Labview virtual instrument. This fundamental experiment from the vibration area is used at McNeese State University in many different ways throughout the mechanical engineering curriculum. First, it is used in the freshman level Introduction to Engineering course as an example of a typical modern engineering laboratory set up. Second, it is a very popular demonstration used in the sophomore level Strength of Materials course during the discussion of stress-strain relations and how strain measurements are used to derive information about stress. Third, it serves as an example of transducer integration in the junior level Engineering Measurements Laboratory, illustrating operational principles of three transducers and the potential of mathematically deriving the same information from different transducers. Fourth, being a common application described in almost every mechanical vibrations textbook, it serves as a very effective demonstration in the Mechanical Vibrations senior level course emphasizing vibration measurement devices and the agreement between theory and experiment. Finally, it is a moderate difficulty example used in the senior level Virtual Instrumentation course that involves data acquisition, data processing and analysis as well as an elaborate human-machine-interface. Even though students encounter the same experiment in many different courses, each presentation of this experiment satisfies different learning objectives, complements and expands the previous presentation and illustrates the open-ended aspect of quality engineering education.