Assessing the Applicability of Digital Image Correlation (DIC) Technique in Tensile Testing of Fabric Composites

Abstract

Approved for public release; distribution unlimited. ii REPORT DOCUMENTATION PAGEForm Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. REPORT DATE (DD-MM-YYYY) February 20132. REPORT TYPE ARL-TR-6343 SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR'S ACRONYM(S) SPONSOR/MONITOR'S REPORT NUMBER(S) DISTRIBUTION/AVAILABILITY STATEMENTApproved for public release; distribution unlimited. SUPPLEMENTARY NOTES ABSTRACTPerforming mechanical characterization of novel structural materials and accounting for the types of failures observed and the heterogeneous nature of fiber-reinforced composites (FRCs) require non-contact strain measurements such as Digital Image Correlation (DIC), a photogrammetric technique that relies on a series of digital images taken during mechanical testing to calculate displacement within a local field. This work assesses the applicability of DIC in determining strains in thick fabric composites by examining two different engineering strain measurement methods available in DIC: (1) the average strain of the full strain field of the tensile specimen and (2) the strain between two gauge points. The results indicate that the difference between the two strain measurement methods is minimal until near the point of failure. However, the full strain fields of the front and back surfaces of the tensile specimen differed significantly during the initial loading. The usage of a single camera DIC system that records only one side of specimen does not accurately capturing bending behavior in the specimen and may inaccurately report the mechanical properties. The DIC technique has to be applied properly in mechanical testing to assure compliance with American Society for Testing and Materials (ASTM) testing methods and other test standards. iii SUBJECT TERMS

A comparative study on the electromechanical properties of 3D-Printed rigid and flexible continuous wire polymer composites for structural health monitoring

“…This can be done by measurement of both axial and transverse to fully understand the mechanical behaviour of the composite. The method used is called two-dimensional digital image correlation (2D-DIC) [14]. DIC has been commonly used to detect surface deformation of composites.…”