Authors: N Li M A Sutton H W Schreier J L Turner N Mani
Publish Date: 2016/05/16
Volume: 56, Issue: 7, Pages: 1281-1291
Abstract
An optimized particle tracking methodology using rigid spherical markers embedded within a material is developed for use with volumetric images Using synthetic volumetric images with additive Gaussian intensity pattern noise in both the undeformed and deformed states numerical simulations are performed to quantify the positional errors that accumulate at each marker position during the optimal tracking process To quantify the positional errors Monte Carlo simulations are performed to obtain the marker position variability for a range of key parameters including marker radius image intensity noise level and marker spacing Using theoretical analyses to quantify strain metric variability results show that a without intensity noise there is a “sinusoidal” bias trend for subvoxel displacement that is maximum at 04 and 06 subvoxel positions b with intensity noise up to 10 the standard deviation range is a nonlinear function of marker radius decreasing to 003 voxels when the marker radius is 9 voxels and rising to 025 voxels for markers with a radius of 1 voxel c standard deviation in the line strain is approximately 2σC /L where σC is the standard deviation in marker centroid position and L is the distance between markers and d the standard deviation in shear strain is approximately 8σC /LTechnical and computer support provided by the Department of Mechanical Engineering at the University of South Carolina is gratefully acknowledged In addition the financial support provided through NASA Cooperative Agreement NNX13AD43A and by the State of South Carolina NASA EPSCoR program office are deeply appreciated
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