A Novel Experimental Strategy for In situ SR-CT Mechanical Loading Test

Abstract

In synchrotron radiation computed tomography (SR-CT) of mechanical loading process, accurate reconstruction of finite angle projection information shielded by mechanical loading devices is a bottleneck problem. For accurate characterization, an experimental strategy for in situ SR-CT mechanical loading test was proposed in this manuscript, which was called "finite angle CT reconstruction method based on tilted sampling information recovery" or TSIR-CT. Effectively recovering the information lost in finite angle CT is a fundamental solution. From the new perspective of the frequency domain, the tilt sampled projection information was utilized to recover the missing angle information. A series of numerical reconstruction experiments were carried out to verify the new method. It was indicated that the reconstruction results of TSIR-CT method have been improved quantitatively comparing with filtered back projection (FBP) and algebraic reconstruction technique (ART) method. For the 506th layer from top end of the 3D test model, the standardized covariance criterion for evaluating similarity was increased from 0.8400 of FBP and 0.9148 of ART to 0.9357, respectively. Finally, this new method was validated using actual SR-CT data and demonstrated effective improvement of reconstruction quality. This new method is suitable for in situ SR-CT mechanical loading test.