The linear dynamics of a microsensor accelerometer modeled as a cantilever beam with an end mass
Abstract
Two classes of accelerometers are being developed using silicon microsensor technology. One class of accelerometers will be used to measure accelerations on the order of 10(exp 6)g range. A dynamic model of these devices is derived in order to aid in their design and characterization. Both types of accelerometers axe modeled as a flexible cantilever beam that is fixed at one end and has a mass attached to the free end. Linear motion about a (straight) horizontal equilibrium shape is considered. The natural frequencies and mode shapes of the model are calculated in terms of the system geometry and material properties. With these results, the continuum model is discretized into a set of modal equations. The responses of the discrete model subject to an impulsive force, a step force, and a singlefrequency harmonic external excitation are determined. A comparison between the characteristics of a lumped mass model and a onedegreeoffreedom modal model is presented. Finally, numerical values are given for an example case of a beam without the end mass.
 Publication:

NASA STI/Recon Technical Report N
 Pub Date:
 August 1994
 Bibcode:
 1994STIN...9517963L
 Keywords:

 Accelerometers;
 Cantilever Beams;
 Dynamic Models;
 Microelectronics;
 Sensors;
 Silicon;
 Continuum Modeling;
 Harmonic Excitation;
 Mathematical Models;
 Resonant Frequencies;
 Vibration Mode;
 Instrumentation and Photography