2017 Fiscal Year Annual Research Report
Development of high-accuracy and large-view-field deformation measurement technique to investigate micro-nano-scale deformation distributions around interfaces
| Project/Area Number |
16K17988
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| Research Institution | National Institute of Advanced Industrial Science and Technology |
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Principal Investigator |
王 慶華 国立研究開発法人産業技術総合研究所, 計量標準総合センター, 研究員 (20726856)
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| Project Period (FY) |
2016-04-01 – 2018-03-31
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| Keywords | Deformation measurement / Strain distribution / Stress concentration / Moire technique / Image processing / Phase analysis / CFRP / Optical method |
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| Outline of Annual Research Achievements |
For understanding the failure mechanisms of laminated carbon fiber reinforced plastic (CFRP), in this year, the full-field deformation distributions of CFRP specimens under three-point bending tests were measured and analyzed. Both the normal and shear strain distributions of CFRP under different loads were investigated under a laser microscope using the moire technique. Strain concentrations were detected around interfaces of the CFRP specimens. The results are useful for evaluating the deformation characteristics and mechanical properties of CFRP.
In the total period of two years, to achieve high-accuracy and large-view-field deformation measurement, the second-order moire method and the reconstructed multiplication moire method have been developed. Two-dimensional strain distributions at the micron and nano scales in a large field of view are able to be accurately measured without rotating the specimen stage or the scanning direction. The microscale strain distributions of laminated CFRP specimens have been investigated under mechanical bending tests. The shear strain concentrations emerged around the interfaces have been used to evaluate the interlaminar shear behaviors, and the tensile strain concentrations along the loading direction have pointed out the micro crack locations of CFRP. This research is able to provide important information for understanding the failure mechanisms and facilitating optimization design of composite materials
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