Shear behavior and strain transmission mechanism in bonding interface of robust toughened epoxy/flattened bamboo composites

IF 12.7 1区材料科学 Q1 ENGINEERING, MULTIDISCIPLINARY

Composites Part B: Engineering Pub Date : 2025-02-22 DOI:10.1016/j.compositesb.2025.112334

Qingdi Jia , Mingjie Guan , Shuai Qian , Mengyu Wu , Pulin Che , Xu Liu

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引用次数: 0

Abstract

To improve the brittle bonding interface of epoxy/flattened bamboo composite (EFB) and expand its application in bamboo buildings, the effects of bonding structures, alkali-treated surface, and toughened epoxy on shear bonding behavior of EFB were systemically investigated to completely understand bonding interface mechanism and novelly simulated models was analyzed. The microstructure and chemical bonding group of the EFB bonding interface were characterized to reveal the toughening bonding mechanisms. The tensile shear behavior of the bonding interface was analyzed by digital image correlation (DIC) and the strain transfer mechanism was simulated by finite element analysis (FEA). Results indicated that the bonding interphase between epoxy and flattened bamboo primarily involved mechanical interlocking in the bonding interface and chemical bonding in the parenchyma cells. The alkali-treated surface and toughened epoxy group (ATEG) improved epoxy penetration on flattened bamboo surface changing the interphase between epoxy and bamboo interface. Alkali-treated surface and toughened epoxy significantly enhanced shear strength and fracture energy of EFB. The maximum dry shear strength of ATEG was higher than control group, with increases varying across the three bonding structures. Under hygrothermal conditions, ATEG achieved the highest wet shear strength in core-reinforced structure with bamboo failure of 60 %. DIC analysis revealed the improvement of strain continuity and dispersion in ATEG under dry conditions, while strain concentration occurred mainly in interphase of EFB bonding interface under hygrothermal conditions leading to the debonding failure. FEA illustrated that alkali-treated surface and toughened epoxy reduced strain concentration in the interphase of bonding interface and improved strain distribution of EFB, consistent with DIC analysis.

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来源期刊

Composites Part B: Engineering 工程技术-材料科学：复合

CiteScore

24.40

自引率

11.50%

发文量

784

审稿时长

21 days

期刊介绍： Composites Part B: Engineering is a journal that publishes impactful research of high quality on composite materials. This research is supported by fundamental mechanics and materials science and engineering approaches. The targeted research can cover a wide range of length scales, ranging from nano to micro and meso, and even to the full product and structure level. The journal specifically focuses on engineering applications that involve high performance composites. These applications can range from low volume and high cost to high volume and low cost composite development. The main goal of the journal is to provide a platform for the prompt publication of original and high quality research. The emphasis is on design, development, modeling, validation, and manufacturing of engineering details and concepts. The journal welcomes both basic research papers and proposals for review articles. Authors are encouraged to address challenges across various application areas. These areas include, but are not limited to, aerospace, automotive, and other surface transportation. The journal also covers energy-related applications, with a focus on renewable energy. Other application areas include infrastructure, off-shore and maritime projects, health care technology, and recreational products.