Publication Date


Date of Final Oral Examination (Defense)


Type of Culminating Activity


Degree Title

Master of Science in Mechanical Engineering


Mechanical and Biomechanical Engineering

Major Advisor

Zhangxian Deng, Ph.D.


Dylan Mikesell, Ph.D.


Mahmood Mamivand, Ph.D.


Nuclear reactors have large needs for in-pile sensors that are durable in high temperature, radioactive, and corrosive environments. With the use of multiphysics finite element analysis (FEA) researchers can speed up sensor prototyping. FEA also allows for a better fundamental understanding of sensors and enables sensor optimization. This research focuses on three types of in-pile sensors developed at Idaho National Laboratory: acoustic sensors, linear variable differential transformers (LVDT), and capacitance based strain gauges (CSG). Two acoustic sensors, magnetostrictive waveguides and piezoelectric surface acoustic wave (SAW) sensors were first modeled. These models showed the acoustic wave patterns and estimated the speed of sound. The modeling results were compared to results from laser Doppler vibrometer testing. The model was implemented to enhance the performance of the sensor designs. This research then modeled a LVDT sensor used to measure fuel rod deformation and structural health monitoring. A parametric FEA study was completed for the purpose of sensor miniaturization. The FEA model was also used to investigate the potential of adding a fiber optic cable through the LVDT core. This research eventually modeled CSGs used in nondestructive structural health monitoring. Multiphysics models were used to investigate the discrepancies in experiments and previous analytical models.