Numerical Evaluation of Displacement and Acceleration for a Mass, Spring, Dashpot System - 2004 ASEE Conference

P.Avitabile, J.Hodgkins

A laboratory project requires measurements for the displacement and acceleration of a simple mass-spring-dashpot system.  Students acquire digital data using an LVDT (linear variable differential transformer), accelerometer and other transducers to obtain this displacement and acceleration data.  The data acquisition system and transducers are intentionally selected such that the majority of possible errors exist in the data (drift, bias, offset, quantization, etc).  This data is integrated and differentiated to compare displacement measurements to acceleration and acceleration measurements to displacement through numerical processing of the measured data via spreadsheet calculations.  Students struggle with this “less than perfect” data to emphasize the importance of good measurements.

 In order to firmly instill these concepts, this laboratory exercise is revisited later in the semester to re-measure the mass-spring-dashpot system with improved instrumentation and better understanding of the problems that need to be addressed.  The students are better equipped to revisit this laboratory at the end of the semester after having been exposed to a wide variety of different measurement problems.

 In addition to a detailed evaluation of the data, each student is required to write a final report addressing all aspects of the test and analysis of the data.  The report must address the data with summary, conclusions and, most importantly, recommendations for future improvement of the test/analysis process.   The project is discussed in this paper and the overall project is described.

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In the meantime, e-mail Peter_Avitabile@uml.edu for copy of paper