@phdthesis{oai:tokyo-metro-u.repo.nii.ac.jp:00004579,
 author = {ヘルワン, ジョニー and Herwan, Jonny},
 month = {Mar},
 note = {Carbon fiber reinforced plastics (CFRP) possess a superb strength and stiffness to weight ratio, thus have been used increasingly for light weight structures. However, conventional CFRP are very weak in the thickness direction and prone to be delaminated on interlaminar surfaces. To overcome this issue, stitching technique has been attracted a lot of attention. This dissertation aims to evaluate mode II (shear mode) delamination of stitched composites through experiment and finite element simulation. Based on literature review, evaluating mode II delamination behavior of stitched composites is facing a serious problem. The testing specimens were failed before crack propagation. Considering this issue, a modified method called tabbed end notched flexure (TENF) test is proposed and the effects of stitching parameters are investigated. It is found that the laminate with maximum stitch density and stitch thread thickness in this study have energy release rate 2.4 times of those unstitched one. To understand the crack bridging mechanism, a single stitched laminate under shear loading has also been investigated using a novel test called interlaminar shear test (IST). Based on this test, finite element simulation of TENF test has been developed. Using cohesive element (to simulate crack propagation plane) and spring connector element (to present the stitch thread), high accuracy of finite element modeling was achieved. Finally, the finite element model is extended to understand stitched laminate behavior under four point end notched flexure (4ENF) and quasi static indentation test., 首都大学東京, 2016-03-25, 博士（工学）},
 school = {首都大学東京},
 title = {Experimental and Numerical Study on Mode II Delamination Behavior of Stitched CFRP Laminate},
 year = {2016}
}