"A new way of biomometic processing for composites" were successfully appraised

八五重点项目“复合材料仿生制备的新途径”通过评议复合材料是新型材料的一个重要分支,具有多种优良性能但由于复合工艺复杂和传统设计思想的束缚,研制工作往往达不到预期效果.天然生物材料经过亿万年的选择进化,造就了优异的结构形式,具有优良的综合性能.这些事实启发人们从材料科学的观点去观察分析天然生物材料的结构机理和组合形式,以期从一个崭新的角度去改进复合材料的研究状态.在国家基金委七五重大项目的支持下,中科院....     

八五重点项目“复合材料仿生制备的新途径”通过评议

八五重点项目“复合材料仿生制备的新途径”通过评议复合材料是新型材料的一个重要分支，具有多种优良性能但由于复合工艺复杂和传统设计思想的束缚，研制工作往往达不到预期效果．天然生物材料经过亿万年的选择进化，造就了优异的结构形式，具有优良的综合性能．这些事实...     

基于仿生技术的高强度复合材料的研究进展

自然界造物的方式是人们制备高强度复合材料的榜样,自然材料的优异特性可以归结为长期自然进化和自然选择条件下所形成多尺度的多级组装结构。阐述了目前研究较多的仿生技术的特点,挖掘了这几类仿生材料的主要组成成分和多级结构实现高强度的机制,重点论述四大类仿生高强度复合材料:基于植物的仿生复合材料、基于动物的仿生复合材料、基于细菌的仿生复合材料、基于天然矿石的仿生复合材料的制备过程和增强机制的研究;揭示了通过仿生手段实现复合材料高强度的原理,并指出其应用领域和目前研究中存在的问题。     

自组装制备有机/无机层状复合材料

自然界中形成的生物材料在结构和性能上具有优异的配备性。模仿生物矿化的形成机制,利用自组装原理能够仿生合成出性能优良和具有多级结构特点的有机/无机界面层状复合材料。本文在总结近年来最新研究的成果上,简要介绍了自组装和生物矿化的机理,重点阐述了基于无机相层的自组装和以有机大分子为模板自组装制备有机／无机层状复合材料两种合成连径,并对未来的发展趋势做了展望。     

生物自然复合材料的结构特征及仿生复合材料的研究

经过若干世纪的选择进化, 生物自然复合材料昆虫外甲壳的细观结构高度优化, 使其具有种种优良的性质。本文研究了昆虫外甲壳的细观结构特征, 这些结构特征为人工合成复合材料提供了一些有益的启示。按在昆虫外甲壳中发现的双螺旋铺层结构和纤维绕孔铺层结构, 用玻璃纤维和环氧树脂制备了仿生铺层复合材料, 比较实验表明, 仿生铺层复合材料比常规铺层复合材料有更高的强度和断裂韧性。      

甲虫鞘翅结构仿生复合材料研究进展

甲虫鞘翅是微细结构高度优化的自然结构复合材料,具有优良的力学性能。对甲虫鞘翅的微细结构和力学行为进行研究并用于复合材料,将对复合材料的开发提供有益的设计思想。本文综述了关于昆虫鞘翅的微细结构、力学行为和仿生复合材料方面的研究现状。     

天然和仿生柔性生物结构的设计

自然界中生物材料表现出的力学性能与其结构设计形式紧密相关。柔性生物材料多为多级结构设计,其独特的功能梯度特征使其具备优异的变形能力及良好的断裂韧性。本文借鉴工程结构设计基本单元的思想提出柔性结构仿生元素理念,根据几何形态将结构仿生元素分为：线元素、梁元素、柱元素、板壳元素、薄膜元素及组合元素。根据系统论的观点建立仿生柔性结构设计体系,归纳总结出柔性仿生结构的设计准则,并基于鱼鳞梯度结构设计新型仿生功能梯度板。通过有限元的方法对功能梯度板归一化自然频率进行分析。结果表明,类鱼鳞功能梯度板具有柔韧性及刚度软化特性。阐述了仿生柔性结构的设计方法,包括模仿设计、组合设计及选择匹配设计。     

功能梯度骨质生物材料的研究进展

功能梯度骨质生物材料为根据人体自然骨的特殊结构,结合金属材料和生物陶瓷材料各自的优点而制备的一类既具有仿生孔隙分布,又具有良好力学性能的骨质生物复合材料.简要介绍了功能梯度骨质生物材料的研究背景,评述了Ti基、316L不锈钢基、Co-Cr-Mo基、Ti4Al6V基四大类功能梯度骨质生物材料的研究进展.同时指出,相比其它制备方法,粉末冶金法由于其近净成形的特点在制备功能梯度骨质生物材料时具有更大的优势.     

非贯通球形空腔型轻质仿生结构的设计及其力学性能

为设计并开发轻量型仿生复合材料,分析了东方龙虱鞘翅断面的微观结构,发现龙虱鞘翅的内部空腔结构为非贯通球形空腔。受龙虱鞘翅独特结构的启发设计了一种轻质仿生结构,球形空腔以正六边形的形式分布于该结构内部。为考察该仿生结构的力学特性,引入了两种常见的中空结构,并借助有限元分析软件ANSYS分别对该仿生结构和其他两种常见的中空结构的压缩、拉伸及弯曲性能进行了有限元分析和对比研究。结果表明:该仿生结构较其他两种常见的中空结构具有更强的抗压能力、抗拉能力及更高的屈服强度,力学性能优异。该仿生结构在材料结构方面为研制新型仿生复合材料提供了仿生学参考。     

冷冻铸造技术制备仿贝壳层状结构陶瓷复合材料研究进展

贝壳珍珠层是一种天然的层状结构复合材料,类似"砖和泥"的软硬相交替的层状分级组装结构赋予其优良的力学性能。通过对贝壳的珍珠层进行仿生研究,人们已利用不同技术如冷冻铸造技术等,制备了一系列仿生高强超韧层状复合材料,并且这些材料在航空航天、军事、民用及机械工程等领域表现出广阔的应用前景。首先介绍了贝壳珍珠层的结构性能,并对其断裂机制进行了阐述;然后综合介绍了冷冻铸造技术的发展历程、作用机理、控制因素、装置设计和总体工艺流程。在此基础上,对制备仿贝壳层状结构陶瓷复合材料的表观密度、多孔陶瓷的孔隙率进行介绍,综述了多孔陶瓷的性能、陶瓷/金属层状结构复合材料以及陶瓷/聚合物层状结构复合材料的特点和应用,最后分析和总结了在研究仿贝壳层状结构陶瓷复合材料过程中出现的问题,并对该复合材料的未来发展趋势做了一定的预测。     

利用木材介孔结构制备新型复合材料研究进展

综述了近年来关于木材多孔结构的新概念以及利用木材多孔结构制备新型复合材料和功能材料的新方法、新技术．重点介绍了陶瓷化木材、金属化木材的制备和应用以及以木材为多孔模板的新材料的合成。利用木材独特的多孔结构和介孔结构，设计、制备结构和功能独特的新材料是仿生材料科学和介孔材料科学一个非常值得关注的研究领域。     

A dual-functional polymeric system combining shape memory with self-healing properties

With the aim of seeking a convenient way for integrating functional materials, a polymeric system, presenting both self-healing property and shape memory behavior, was proposed and constructed based on epoxy based shape memory polymer (ESMP) and poly (ε-caprolactone) (PCL). The synthesis principle of PCL–ESMP composite was based on phase separation phenomenon between the two ingredients. Such phase separated PCL–ESMP composite reserved melting transition of PCL and glassy transition of ESMP, respectively, which was the crucial mechanism for achieving self-healing performance and shape memory behavior. A bending-recovery experiment demonstrated that PCL–ESMP composite possessed excellent thermal-induced dual-shape memory effect. Meanwhile, single edge notched bend testing revealed that such composite exhibited desirable self-healing performance as well. This article introduced a simple contrivable concept and exhibited some experimental results of the PCL–ESMP dual-functional composite system. The promising applications are expected to more widely, such as functional composite matrix and intelligent structures.     

Biomimetic Design and Test of Composite Materials

A series of superior properties will make composites the most important structural materials in thenext century.But they are difficult to design owing to the complexity of structure and processing.Biomaterials had been naturally selected and evolved for millions of years,a great variety of their ra-tional composite structures could be taken as our reference in the biomimetic design of compositematerials.There are many difficult problems in the current study on composite materials such as:brittleness of continuous fibers and difficulties in interface design;easy pull-out of short fibers frommatrix causing failure in reinforcing;being less easy in selecting the aspect ratio of whiskers and dif-ficulties in finding the way of toughening composites of ceramic matrices as well as the way of heal-ing inner damages.After describing the distinct composite features,the functional adaptability andself-healing ability of biomaterials,several examples o.f biomimetic design of composite materialshave been listed in this paper:the optimum design of composites simulating bamboo structure;thefine structure of bamboo fibers;the dumb-bell model simulating animal bone;the model on thepull-out of fiber with fractal-tree structure and some tentative works on the healing of inner damagein composite materials The methodology of biomimetic design and its future have been given at theast part of this paper.     

Mechanical adaptation of biological materials — The examples of bone and wood

Many biological materials have the property of being responsive to their environment combined with the ability to adapt to possible changes in this environment. Two prototypical responsive biological materials are presented and confronted with each other: bone and wood. These biomaterials have attracted research interest of materials scientists mainly investigating structure–property relationships. Ageing and diseases of bone and the widespread use of wood as construction material, fuel research from a medical and technological perspective. After describing the structure of bone and wood, the mechanisms of adaptation – adaptive growth and remodelling – are introduced, which allow structural changes in these biomaterials. Four examples are presented how these mechanisms are used for adaptation on different length scales starting from the shape at the macroscopic scale to the composite structure at the nanoscopic scale. In all these examples the biomaterials respond to mechanical stimuli and try to improve their mechanical performance. While some of the embarked strategies are very similar in bone and wood, like the arrangement of fibres and the architecture of the nanocomposite, differences can be observed in other situations like growing a supportive cylindrical structure or in the reorientation of structures. At the core of these differences is the capacity of living bone to deposit material where needed, but also to remove superfluous material. In contrast, a tree can only grow by adding new material.     

Self-healing of mechanical damage of polyethylene/microcapsules electrical insulation composite material

Polyethylene (PE) cable has become an important carrier of the modern power grid due to its excellent electrical insulation performance. However, small damages can inevitably occur during the preparation and operation of the materials, which can distort electric field and trigger discharge, seriously threatening power supply safety. The self-healing of insulation materials by doping microcapsules is a new research innovation. In this paper, the self-healing PE/microcapsules insulation composite material was prepared, and the self-healing behavior of mechanical damage was emphatically analyzed by scratch damage test and crack propagation simulation. The results show that the composite material with 1 wt% microcapsule has better insulation strength. Moreover, the composite material can fill the defective structures, restore local electrical properties, and reverse the deterioration process of the material. The properties of PE/microcapsules composite material are mainly related to the characteristics of the microcapsule itself and the interface introduced by the microcapsules. The properties of the repaired product can directly affect the recovery degree of the damaged area. The stress action during damage can smoothly trigger its self-healing behavior. In conclusion, the PE composite material doped with 1 wt% microcapsules can achieve a good self-healing effect on mechanical damage.

     

一种在细观尺度上仿生的复合材料模型

本文分析了自然界常见的生物复合材料的结构,找出了有共性的规律,提出了双重螺旋的仿生复合模型。对该模型进行了理论分析,在细观尺度上将仿生学运用于复合材料的设计与制备。用碳纤维/Sn 复合材料对该模型进行了检验,结果发现,与均匀排布的单向长纤维复合材料比较,其抗拉强度显著提高(超过了40%)。     

微胶囊型自愈合聚合物基复合材料研究进展

自愈合材料是一种可以模仿生物体自行愈合的新型智能材料,具有广泛的应用前景。微胶囊型自愈合聚合物基复合材料是近年来复合材料自愈合方法领域内的研究热点之一。本文对目前聚合物基复合材料自愈合方法进行了综述,着重介绍了微胶囊型自愈合聚合物基复合材料的自愈合概念和机制、微胶囊结构及其技术发展状况,并详细介绍了微胶囊的芯材、壁材、自愈合基体材料及微胶囊临界应力等因素对复合材料自愈合性能的影响,以及自愈合效率的评估方法。最后讨论了微胶囊型自愈合聚合物基复合材料的发展趋势和面临挑战。     

聚合物基复合材料自修复的研究进展

复合材料的自修复功能已成为智能材料研究的重点之一。自修复主要包括外援型自修复和本征型自修复,外援型自修复种类主要包括微胶囊型、中空纤维型以及微脉管型自修复;本征型自修复主要包括可逆共价键和可逆非共价键自修复。系统地阐述了这几种典型自修复方法的研究进展及其优势和不足,展望了自修复复合材料的发展及应用前景。     

基于混合单元建模的复合板热诱导结构振动研究

针对复合板的热诱导结构振动问题，提出一种新的混合单元计算模型，将三维和二维单元组成混合单元，利用不同类型单元体现复合结构中不同的材料特性，实现对真实复合结构物理特征的高精度模拟。在此基础上基于虚功原理建立了三维形式的复合板瞬态热弹性动力学方程，利用该方法对空间大尺度复合薄板的热诱导扰动进行研究。仿真结果表明，结构固有频率和热容是决定热诱导振动发生的主要内囚，对于一些刚度较大的空间复合薄板，由于空间约束环境弱，整体频率低易发生热诱导结构振动。本研究对于空间大尺度复合平板结构的工程设计具有一定的参考价值。     

Fibre/resin composites for aircraft primary structures: a short history, 1936–1984

The origins of composite materials, in the widest definition of this term, occurred long before recorded history and may be traced through examples of clay reinforced with wood and other natural fibres, the papier mâché of the ancient Egyptians and numerous combinations of wood with leather or metal. The technology behind some of these materials and their applications was no less ingenious than that for today's high performance structural composites, the origins of which can be pin-pointed with accuracy to the concepts and work of N.A. de Bruyne and J.E. Gordon in the late 1930s. In this article a broad-brush outline is given of the history of the development of composites for use in aircraft primary structures, beginning with gelatin and starch reinforced with cellulose fibres and ending with the invention of carbon fibres and their use as a reinforcement for epoxy resins.