This paper addresses the issue of intermittent data loss during transmission of wireless network sensors and the
application of the reconstruction signal for damage detection with the damage locating vector (DLV) method. The
algorithm makes use of frequencies which contribute significant amount of energy in the signal based on Fourier
transform. As the amplitudes are uncertain due to lost data, the Fourier amplitudes are estimated based on least-square fit
of only the measured portions of the signal. The lost portions are reconstructed through inverse Fourier transform. The
procedure is iterated until the discrepancy between estimated lost portions of two consecutive iterations is below a set
threshold. This threshold and the power spectral threshold to demarcate the significant frequencies are selected based on
results from numerically simulated signals. The reconstructed signals are used with the DLV method for damage
detection to investigate the practicality of this procedure. A cantilever truss structure with a pre-stressed cable was
monitored using six wireless sensors. The pre-stressed cable was cut mid-way during random load application and data
collection. The results obtained support the use of the reconstructed signal within the framework of the DLV method.
In this paper, a finite element method to simulate the overall behavior of ultrasonic motor (USM) is proposed. Firstly, an iterative algorithm using ABAQUS® version 6.4 to solve the contact problem with piezoelectric actuation is presented. In each iteration, the dynamic responses of stator actuated by piezoelectric force and updated contact force are solved, from which static (or steady state) contact between deformed stator and rotor are estimated. For the dynamics of stator, three dimensional solid elements are adopted and direct integration method is used because modal-based procedures do not adequately transform the electric loads into modal loads. Rayleigh damping is adopted with the ratio set to 0.5%. For the contact between deformed stator and rotor, Lagrange multiplier method is used to impose the normal and tangential contact constraints between the stator and rotor respectively. Based on the proposed procedure, given the applied torque, axial force, and piezoelectric drive voltages as inputs, the general measures of motor performance are obtained and compared with published numerical and experimental results. The approach presented here provides a more accurate framework with moderate computational cost for modeling USM and serves as a design tool for optimizing prototypes.