包缠结构预混料热压过程中树脂浸渍分析

建立了包缠结构顸混料热压过程中树脂的浸渍模型。结果表明,实验值和模型的预测值吻合较好,该模型可以用于包缠结构预混料热压过程中浸渍时间的预测。利用该模型对混合结构预混料的进一步研究发现,包缠结构预混料中丝束的完全浸溃时间仅略长于混合结构预混料。     

等离子体处理对炭黑/硅橡胶压阻特性的影响

利用等离子体对炭黑进行表面处理,比较不同气体等离子体处理前后炭黑/硅橡胶的压阻性能.试验表明,炭黑经氩气等离子体处理后,所制备的试样电阻减小;而经氮气等离子体处理后,试样的电阻增大,同时提高了电阻的变化范围.原子力显微镜(AFM)测试表明,等离子体处理后的炭黑表面产生明显的凹凸;由扫描电子显微镜(SEM)图像可知,炭黑在硅橡胶中的粒径较小,分散较均匀,这些均有利于提高炭黑/硅橡胶压阻灵敏性.等离子体处理对于发黑/硅橡胶的压阻重复性和迟滞性能等影响不大.     

基于频谱分析的织物粗糙感

传统研究一般通过测试织物表面的几何粗糙度和摩擦性能来预测粗糙感,而认知科学家发现,栅栏粗糙性的辨别取决于表面纹理波动曲线的谐波成分及纹理间距.为深入揭示织物粗糙感的形成机制,基于织物的表面形貌曲线,计算平均粗糙度,统计不同波动高度下的纹理间距,并采用傅里叶方法提取频域内谐波特征,比较分析这些特征值与粗糙感之间的关系.研究表明,织物的粗糙感差异取决于表面波动曲线频域内谐波的最高峰高度,而粗糙感不仅与平均粗糙度有关,也与表面纹理间距有关.     

Dependence of Softness on Fabric Surface Quality and Compressibility

The term ＂softness＂ is loosely used to describe the physical as well as sensory attributes of fabric and other textiles, and several psychophysicai evaluation methods as well as its predicting equations exist. However, the information for physiological mechanism of fabric softness is lack. To explain the blomechauical and the potential neurophysiologicai phecnomenon for exploring fabric softness, accompanying to the procedures in manual exploration for softness and the anatomical multllayor structures of human finer, a contact finite dement （FE） model between finger and fabric is made to conduct an active contact analysis. In present FE model, the effect of surface friction index, compression modulus, Poisson＇s ratio of fabric on softness dlscrimination is Investigated. The interests are in the contributlons of these fabric property variables to contact area, Interracial friction shear stress and contact pressure distributions, which arc significant cognitive variables or stimulus parameters in peripheral neural levels. The mechanistic data for fabric specimens indicates that the basis for the perception of softness of flexible and bulk fabric is likely on the spatial variation of pressure on the skin （or, equivalently the skin displacement and its derivatives） resulting from surface friction phenomenon and compression property of fabric. In present model, however, the effect of Poisson＇s ratio on the total force exerted by fingertip is not significant statistically. Therefore, compression modulus of fabric is, not the only underlying physical variable accounting for peripheral neural response, and also the surface friction phenomenon plays an important role in feeltouch softness of fabric, i.e. the compressibility and surface properties of fabric arc the necessary physical variables involved for the haptic rendering of its softness.     

On the Representation of Multi - layer Woven Structure

A quantitative method is developed to identify the structures of multi-layer woven fabric in this study. Six structural parameters are selected to represent the fabric structure. With some design criteria for the reinforcement of textile composites, the relationships among the structural parameters are derived for different binding patterns of the fabric structure. The conditions, which meet the requirements of structural cell stability,are also discussed.     

Psychometric Properties of Geometrical Texture Features for Tactile Roughness Sensation of Fabric Surfaces

The lack of understanding of the psychometric properties on the basic texture features forming tactile texture sense hinders the development of haptic rendering technology of textiles. The differential threshold and Weber fraction were investigated for a deep understanding of how surface texture features of fabrics affect the perceived roughness sensation by the constant stimulus method and the paired comparison method. The results showed that the differential threshold for the mean deviation of surface profile was0. 86 μm,and that the differential threshold of texture spatial period(TSP) was 2. 48 mm. And also,the difference thresholds and Weber fraction were affected by the reference stimulus intensity. As there is a significant interaction between four extracted texture feature indexes,any of the indexes alone cannot represent roughness sensation of fabrics.     

Effects of Polyethylene Oxide Concentration on the Size of Beads in Electrospun Beaded Nanofibers

Embedding particle drugs in beaded nanofibers by electrospinning has been shown a potential approach to control drug release in tissue engineering. The bead size is one of the critical parameters in controlling the drug release rate. In this study,the relationship between polymer concentration and beads size was investigated. Aqueous polyethylene oxide（ PEO） solutions with different concentrations were prepared to obtain various beaded nanofibers by electrospnning. Optical microscope and scanning electron microscope（ SEM） were used to observe the variation tendency of bead size. With an increase in the polymer concentration,the diameter of fibers between beads became bigger,while the fiber uniformity improved. In addition, the polymer concentration influenced the distribution of bead diameter. Higher polymer concentration would reduce the possibility of small-sized beads formation and improve the uniformity of bead diameter. The study provides a possible way to control the size of beads,which is helpful for further research on the control of particle drug release.     

Anthropomorphic Classification of Tactile Qualities of Woven Fabrics Based on Skin/Textile Friction-Induced Vibrations

The common method classifying tactile qualities of fabrics is indirectly based on their difference of purely mechanical and physical properties. When human skin slides across fabric surfaces, the friction interaction between fabrics and skin will occur and trigger the cutaneouS tactile receptors, which are responsible for perceived tactile sensation. By the extracted features from friction- induced vibration signals, this paper presents an anthropomorphic classification method classifying tactile qualities of fabrics. The friction-induced vibration signals are recorded by a three-axis accelerator sensor, and the entice testing procedure is conducted in an anthropomorphic way to obtain vibration signals. The fast Fourier transform （FFT） is applied to analyzing the recoded signals, and then the classification features are extracted from the FFT data by the neurophysiological properties of tactile receptors. The extracted features are used to classify fabric samples by the softness sensation and the roughness sensation, respectively, and the classification performance is checked by a comparison with those in a sensory evaluation procedure. The results showed that the anthropomorphic objective classification method was precise and efficient to clarify tactile qualities of woven fabrics.     

三维编织复合材料抗侵彻性能--准静态侵彻实验与弹道侵彻有限元计算的对比

用钢制圆柱锥体对四步法三维编织芳纶／环氧复合材料在MTS材料试验机上作准静态侵彻测试，得到准静态侵彻载荷一位移曲线，并由此计算得到侵彻功一位移曲线。在对复合材料侵彻破坏的细观观测中发现，复合材料主要以拉伸断裂方式为主并在受侵彻面伴有压缩和剪切破坏。由于弹道侵彻破坏很难测量侵彻过程中的侵彻功随侵彻位移的变化，这里用有限元程序LS—DYNA960并结合由准静态得到的破坏判据、复合材料力学性质常数模拟动态侵彻，对比准静态侵彻功一位移曲线和弹道侵彻模拟曲线，两者有较好的一致性，表明用该类复合材料的准静态侵彻性能模拟弹道侵彻性能有一定的可行性。     

织物手感的认知原理及其研究

织物手感是纺织品十分重要的性能之一．经过近一个世纪的研究，随着科学技术的发展，对织物手感的表征和评价取得了不少成果．但由于人们对大脑认知行为的认识尚不成熟，对织物手感的神经认知原理还处于探索阶段，导致对织物手感形成机制的理解不深入，从而限制了该方面研究的进展．通过分析织物手感形成的生理基础，归纳了探索织物手感方面的研究工作，试图从认知心理学角度澄清以往在该领域研究工作的模糊认识，分析传统上从认知心理学角度研究织物手感认知属性空间的不足．同时，结合认知神经科学最新的研究结果，寻求织物手感定量表征的发展方向．