Integrated development of CFRP structures for a topless high performance vehicle

When modern saloon cars are re-engineered as convertibles (or roadsters) it is typical for them to lose 50% or more of the body’s torsional rigidity. Consequently the vehicles rarely handle quite as crisply, nor do they ride as well as the coupes from which they derived. This paper highlights the fundamental contributions of advanced composites in achieving the desired value of handling of the Murcièlago Roadster without penalizing the overall weight of the vehicle. To compensate for the absence of the roof structure, the vehicle was strongly redesigned by introducing new structural members and reinforcing existing critical components. A new all-carbon/epoxy composite sub-frame, which spans the entire engine bay, is comprised of elliptical tubular members, and it is the first of its kind in a production vehicle. Engineering of the sub-frame, from preliminary design to manufacturing decisions, is the focus of this paper, and is achieved through a Building Block approach that sets the program within the Integrated Product Development (IPD) strategy that the Advanced Composites Division of Automobili Lamborghini S.p.A. employs for its technology demonstrators. The strategy consists in a concurrent analytical and experimental development of the product, from the initial conceptual design and coupon testing, through the stages of element and subcomponent engineering, to final component manufacturing.     

我国纳米科技的现状与展望

本文概述了纳米科技的沿革，及其在国内外发展的情况，并就我国如何进一步发展纳米科技提出了自己的想法。     

天铁炼铁技术进步

近十年来，天铁集团炼铁厂通过改善原燃料条件；优化炉料结构，提高入炉品位；采用提高炉顶压力、富氧喷煤、低硅冶炼、炉顶气象系统等多项先进技术，使高炉各项经济技术指标逐年提高。     

网络技术在中州分公司计量管理工作中的应用探讨

本文通过对中州分公司正在考虑建设的信息网建设实际情况，结合山东分公司、广西分公司取得的经验，对计量管理信息网的应用进行了探讨。     

复合绝缘子耐电腐蚀特点及其电蚀老化区域性的差异

为了了解复合绝缘子外绝缘材质电蚀老化状态和区域性的差异,对Al(OH)3耐电腐蚀机理、外绝缘材质中Al(OH)3颗粒分布状态和环境污湿因素的实际情况进行了研究。Al(OH)3颗粒分解成水蒸气、析出白色粉末状氧化铝,并催化生成二氧化碳,将使外绝缘材质逐渐微观减薄和加大表面的粗糙度,而引起电蚀老化的污湿环境因素,近期不可能得到改善,因此必然引起其电蚀老化出现区域性差异。此外,外绝缘憎水表面污珠场强变化引起的电晕也是促使电蚀老化的重要因素。     

两栖装甲装备新型防腐材料的研究

沿海地区特殊海洋环境造成装甲装备的严重腐蚀,为了研制一种新型的耐蚀有机涂层,该文作者研究了有机硅改性环氧树脂的化学反应,并对改性树脂的性能进行了测试分析.结果表明,改性树脂克服了环氧树脂的耐温性差、亲水性强以及盐水渗透率高的性能缺陷,为进一步制备该地区装甲装备防腐涂料奠定基础.     

环氧基的PCB对无铅组装的兼容性

综述了环氧树脂基的PCB与无铅化组装的兼容性问题。经过大量试验表明,常规的FR-4基材和双氰胺固化的高Tg基材是不能满足无铅化组装要求的,而采用酚醛固化的中等-Tg的环氧树脂基材是可能成为无铅化组装用基材的。同时,PCB制造过程也起着重要的作用。PCB设计和再(回)流焊的加热梯度也影响着无铅化的性能。     

纳米材料的力学性能

综述了纳米晶体材料和纳米碳管材料的力学性能研究的最新进展。实验数据表明纳米晶体材料的强度与其晶粒尺寸大小的关系并不遵循Hall-Petch方程。相对于常规晶体材料 ,纳米材料的超塑性发生在更低的温度和更高的应变速率下。理论计算和实验数据表明 :纳米碳管是一种有着高刚性、高强度、高韧性和低密度的材料。纳米晶体材料和纳米碳管的异常的力学性能已经有了一些应用实例     

Possibilities and extension of XRD material response analysis in failure research for the advanced evaluation of the damage level of Hertzian loaded components

Due to clearly distinguishable damage symptoms, it is differentiated between the surface and sub‐surface failure mode of rolling bearings. Material states red out by X‐ray diffraction (XRD) residual stress measurements point to a variety of loading conditions especially at raceway surfaces that are associated with several competing failure mechanisms. The corresponding lifetime reduction can range from the lower fatigue strength region to material ratcheting in extreme cases. Relevant position of the microstructural changes and nature of the failure mechanisms are characterized. The time alteration of the XRD material parameters measured at or near the surface and at the depth of the maximum equivalent stress correlates, in a different manner, with the statistical parameter of the 10 % bearing life. Both failure modes are illustrated by concrete examples. Contaminated lubricant and boundary lubrication, which represent practically important surface‐induced failures, are discussed in more detail. Gray staining, i.e. shallow pitting, often occurs without distinct indication of global material aging by means of XRD characteristics. Here, scanning electron microscopy observations and electron microprobe analyses point to corrosion fatigue as acting surface failure mechanism. The interaction between material and lubricant under complex loading regimes particularly of mixed friction and corrosion opens further failure research areas in the field of tribology.     

半金属摩阻材料中铜纤维摩擦磨损行为的研究

用扫描电子显微镜(SME)和X-射线能谱分析法(EDX)对铜纤维增强的半金属摩阻材料与灰铸铁对偶滑摩后的摩擦表面进行了分析,研究了摩阻材料中铜纤维的摩擦磨损行为.结果表明,在摩擦磨损过程中,摩阻材料摩擦表面上铜的分布更加弥散化,并且铜纤维具有集铁作用,因而摩阻材料摩擦表面上形成了富铁贫铜表面工作层;铜能从摩阻材料摩擦表面转移到对偶摩擦表面,故对偶摩擦面上分布一定量铜,这是摩擦副具有稳定摩擦系数和良好耐磨性的关键因素;铜纤维取向对摩阻材料摩擦磨损行为有显着影响.