An Elasticity Approach to the Solidification of Fibre-Reinforced Shells

This paper presents a model of solidification for a fibre-reinforced circular cylindrical channel section under plane strain. Cooling from the inside surface of a cylindrical section of the liquid phase causes a solidification front to move radially through the thickness until solidification is complete. The principal area of interest is the mechanism by which the nature of the temperature field during solidification affects the shape and residual stresses in the final solid part. A special case of the solution is presented and compared with an equivalent result in which solidification of the whole section occurs instantaneously. The mechanism is also relevant to microstructural wrinkling. This revised version was published online in August 2006 with corrections to the Cover Date.     

圆筒形件多次拉深不用压边时的皱曲判定

在分析多次拉深变形特点的基础上,本文建立了塑性失稳皱曲的计算模型。运用压缩塑性失稳理论导出了变形区边缘塑性失稳皱曲的临界切向压应力的表达式,进而得出了圆筒形件多次拉深不用压边时变形区不会皱曲的条件,并以08钢为例进行了对比论证,绘制了拉深塑性失稳皱曲的临界曲线,得到了比较满意的结果。     

空间薄膜结构的褶皱形变预测

空间充气结构技术是一项全新的空间结构构建技术,基于该技术的空间充气结构是未来空间任务的主要需求对象．该结构主要由薄膜构成,因此结构形面精度的保持是关键问题．褶皱是薄膜特有的现象,它的存在会严重影响结构形面精度,因此进行褶皱研究很有必要．根据屈曲理论联合薄膜褶皱的实际构型建立了薄膜结构褶皱的预测模型,分析了矩形平面薄膜受面内水平剪切情况下的褶皱,得到了褶皱幅度和褶皱波长以及薄膜结构产生褶皱时的临界压缩应力,通过与已有文献结果及本文实验结果的比较验证了该分析方法的有效性和结果的正确性．     

Light-Responsive Polyblend Films with Reconfigurable Surface Micropatterns as Rewritable Information Storage Media

Stimulus-sensitive surfaces with tunable morphologies exhibit a wide range of applications in the fields of surface science and engineering. Herein, a cost-effective yet practical strategy is proposed to fabricate photo-sensitive patterning surface on film/substrate wrinkle system based on an azo-containing polyblend. By manipulating the stress field of the bilayer system globally and/or locally upon the stress relaxation triggered by the reversible cis-trans isomerization of the azobenzene, heating/cooling triggered surface wrinkles on the polyblend films could be tailor-made with visible-light-irradiation. Notably, upon selective photo-irradiation, bespoke surface patterns may be cyclically generated or eliminated, allowing these reconfigurable patterned polyblend surfaces to be used as rewritable information storage media for non-ink printing. The as-prepared photo-printed information patterns with high-resolution are shown to be rewritable for multiple cycles and legible for over 90 d in dark ambient conditions. This study not only provides a versatile strategy for flourishing the stimulus-sensitive systems, but also sheds light on the stress relaxation-triggered morphological evolution of the wrinkling polyblend films.