عنوان مقاله
میکروساختار کوتیکول حشره و مقاومت کمپوزیت سوراخ تشکیل شده بیومیمتیک
فهرست مطالب
چکیده
مقدمه
مشاهده میکروساختار کوتیکول حشره با تکنیک SEM
ساخت و تست مقاومت کمپوزیت سوراخ اجرا شده بیومیمتیک
نتیجه گیری
بخشی از مقاله
ساخت و تست مقاومت کمپوزیت سوراخ اجرا شده بیومیمتیک
ازساختار چین منحصر به فرد فیبر و توزیع فیبر نزدیک سوراخ مشاهده شده در کوتیکول حشره (شکل 5) برای طراحی ساختار چین بیومیمتیک استفاده گردید. در این تحقیق، سوراخ اجرا شده با استفاده از پارچه شیشه ای/ اپوکسی بافته شده با 〖0/90〗^° فیبر به جای نوار یکسویه تولید گردید. دلیل انتخاب این ماده استفاده گسترده از پارچه شیشه ای و اپوکسی ها در ساختارهای صنعتی و داخلی بود.
کلمات کلیدی:
Research on the microstructure of insect cuticle and the strength of a biomimetic preformed hole composite B. Chena *, X. Penga , W. Wangb , J. Zhanga , R. Zhangc a 'Department of Engineering Mechanics, Chongqing University, Chongqing 400044, People's Republic of China Department of Applied Physics, Chongqing University, Chongqing 400044, People's Republic of China c Department of Physics and Materials Science, City University of Hong Kong, Hong Kong, People's Republic of China Abstract The insect cuticle is a typical natural composite with excellent strength, stiffness, and fracture toughness. Scanning electron microscope observation of the microstructure of Hydrophilidae (an insect) cuticle showed several unique plies and structural characteristics, which may provide available information to the design of advanced composites. The microstructure found in the vicinity of pore canals in the insect cuticle was used for the design of the composite laminate with a hole. Compared with the composite laminate with a normally drilled hole, it was found that the strength of the specially designed composite laminate increases markedly, which is of important significance to the design of high-performance composites. © 2002 Elsevier Science Ltd. All rights reserved. Keywords: Insect cuticle; Composite; Microstructure; Bionics; Preformed hole; Strength 1. Introduction Insect cuticle is a typical example of a natural composite, the microstructure of which endows it very good mechanical properties, such as excellent strength, stiffness, and fracture toughness. Insect cuticle is, in nature, a composite of fiberreinforced laminate. The fibers, a high-molecular weight polysaccharide called chitin, are embedded in a proteinaceous matrix (Rudall and Kenchington, 1973). Although the components of the cuticle, sugar and protein, in general, possess poor mechanical properties, the insect is able to combine them in a unique way to produce a high-performance material with highly optimized microstructures (Hepburn and Ball, 1973). The research on these microstructures and the corresponding characteristics may provide valuable information for improving current composites and developing high-performance materials. An insect cuticle can be divided into two primary sections: epicuticle and procuticle (Hadley, 1986) (Fig. 1). Epicuticle is the outer layer, consisting mainly of wax, lipid, and protein without chitin fibers. This layer, being 0.1 - 0.3 |xm in thickness, acts as an environmental barrier and contributes little to the shape or the strength. The procuticle, the structural division, about 10-100 |xm in thickness, provides shape and mechanical stability. It can be further divided into the exocuticle and the endocuticle, both of which contain chitin fibers and a protein matrix. The chitin fibers, containing bundles of microfibers, are embedded in a proteinaceous matrix and arranged in a series of thin lamina with various orientations. The fiber ply orientation in the cuticle received much attention. Several theories have been proposed for specific orientation of these fiber plies, among which the most widely accepted one is the helicoidal model proposed by Bouligand (1965). It takes the structure as a series of thin unidirectional lamellas stacked one by one with the orientations rotated by a small and nearly constant angle between lamellas. The model modified by Neville (1970) involves the same stacking sequence, but curve-fibers were assumed in each lamella. Several other models were also proposed, including the screwcarpet model by Weis-Fogh and the cross-hatch model (Hepburn, 1983), which used the form of a woven cloth or fabric. Another model receiving extensive attention is the dual helicoidal model proposed by Schiavone and Gunderson (1989), which describes the structure as two alternating helicoids rotating in a clockwise direction from the outside to the inside of the cuticle. One of the purposes of this study is to obtain more information about the microscopic structure of insect cuticle with scanning electron microscope (SEM) techniques, and find the relation between the microscopic structures and macroscopic mechanical behavior of insect cuticle. other purpose of this study is to explore the possible
