The competition between crack penetration and crack kinking is addressed for a mode I macroscopic crack in an orthotropic elastic solid. Cohesive zones of finite peak strength and finite toughness are placed directly ahead of and orthogonal to the plane of the parent crack. The cohesive zone ahead of the crack tip is tensile in nature and leads to crack penetration, whereas the inclined zones slide without opening under a combined shear and normal traction, and give crack kinking. Thereby, the competition between continued crack growth by penetration ahead of the crack tip versus kinking is determined as a function of the relative strength and relative toughness of the cohesive zones. This competition is plotted in the form of a failure mechanism map, with the role of material orthotropy emphasized. Synergistic toughening is observed, whereby the parent crack tip is shielded by the activation of both the tensile and shear (kinking) cohesive zones, and the macroscopic toughness is elevated. The study is used to assess the degree to which various classes of composite have the tendency to undergo kinking.
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http://dx.doi.org/10.1007/s10704-017-0227-x | DOI Listing |
Anal Chem
January 2025
College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
The development of a sensory signal amplification approach is very crucial for rapid and precise detection of aflatoxin B (AFB). However, such approaches remain scarce due to the weak interactions between AFB and the sensing probes. Herein, the first example of a dual-excitation fluorescent platform for antibody-free AFB detection is reported, which is assembled by an ordered π-π stack of cationic perylene derivative (PTHA) and tris(2,2'-bipyridine)ruthenium(II) [Ru(bpy)].
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January 2025
School of Civil Engineering and Communication, North China University of Water Resources and Electric Power, Zhengzhou, 450045, China.
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Department of Orthopaedic and Traumatology, Trabzon Kanuni Training and Research Hospital, Trabzon, Turkey.
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ACS Omega
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