Advances in measuring rotation with MEMS accelerometers

Model space, sensor frequency bandwidth, and sensor inventory limitations create challenges in capturing both the dynamic and static response of specimens in physical modeling. Micro-Electro Mechanical Systems (MEMS) based accelerometers are an attractive choice in centrifuge testing because of their small sensor size, robustness, and simplification of the sensor reference frame. In addition to capturing dynamic accelerations, MEMS at steady state measure the static component of centrifuge acceleration (an). Therefore, the change in an is directly related to the residual angle of the MEMS sensor after shaking. The process for combining MEMS inclination and acceleration measurements to obtain dynamic and static rotation is outlined. Results from two centrifuge tests are presented where MEMS were designed to capture rotations during foundation lateral slow cyclic testing, and post-event residual rotations of rocking structures. This method will help improve result accuracy while simplifying sensor configuration in centrifuge testing.