具有库仑摩擦的非线性单摆运动过程的数值分析

文章研究了具有库仑摩擦的非线性单摆的运动过程数值分析方法,即将随运动量变化而变化的库仑摩擦力矩含在状态的程序数值积分过程中,给出了自由摆动过程和强迫摆动过渡过程的一般分析思想;并给出了具体算例,以表明分析结果的可行性,为精确系统模型中阻尼系数的确定提供了一种计算方法。     

碳纳米管及其在摩擦材料中的应用

本文介绍了碳纳米管的力学性能和独特的孔隙结构，分析了碳纳米管作为摩擦材料添加剂的可行性和近期碳纳米管摩擦材料发展情况，为工业用材的发展提供了可供参考的新方向。     

对华纺织品贸易保护措施及保护国别的特征研究

纵观这几年我国纺织品的外贸发展历程，持续两位数的高速增长确实令人鼓舞，但是，国际社会针对我国纺织品的贸易摩擦也层出不穷，并且已经成为影响我国纺织产业健康有序发展的一大障碍，为此，本文主要围绕对华纺织品贸易保护措施特征及保护固别特征进行深入分析。从而揭示我国纺织品贸易摩擦多发的国别原因，为建立纺织品进出口贸易分类监测系统和风险预警系统奠定了一定的基础，同时也克服了利用同一指标、同一标准去监测不同固别的缺点，使预警信号具有更强的针对性和实用性。     

Static load test and load transfer mechanism study of squeezed branch and plate pile in collapsible loess foundation

As a special geological phenomenon, the character of collapsible loess foundation is collapsible when penetrated by water. This character leads to the soil losing load bearing capacity largely and may lead to foundation failure. Pile is a popular foundation used in collapsible loess. The squeezed branch and plate pile is a new type of pile developed in recent years and has not be used in a project before. In this paper three squeezed branch and plate piles are tested in collapsible loess after immersion processing. The results may be used for reference in similar construction project, and to provide theoretical references for de- signing of the squeezed branch and plate piles in engineering practice.     

基于有限元分析的纳米级微进给平台设计

设计了一种利用弹性铰链作为预紧机构、高精度滚动导轨作为导向机构的单PZT驱动的微进给平台。利用有限元方法对微进给平台的结构和静、动态特性进行了研究。在静态特性中着重分析了微进给平台的静态刚度,得出整个动平台的工作平面上的刚度分布图。在动态特性分析中着重研究了微进给平台的模态振型、固有频率和谐波激励响应,得出了激进给平台在动态激振力作用下的特性。最后分析了微进给平台工作平面上静态刚度和动态刚度变化很大的原因,并提出一些改进的措施。     

轧机提速对四列圆柱滚子轴承的影响和优化措施研究

国内某钢厂轧机进行了提速,导致支承辊上四列圆柱滚子轴承出现温升过高情况。针对此问题,对该轴承提速前后的摩擦力矩和发热量进行了计算比较,显示速度对摩擦力矩的影响不明显,与发热量近似成正比例关系。对轴承进行了降低温升优化。采取的主要措施为减少相互滑动部位接触面积,增设散热油路;降低接触面粗糙度;优化轴承油孔改善散热效果。提出了滚子端面和挡边点接触的简化计算方法。优化后的轴承经应用后温升明显减缓,提高了使用寿命。     

钢筋混凝土预制方桩静压施工质量监理

通过工程实践 ,提出钢筋混凝土预制方桩采用静力压桩施工质量监理工作方法     

Exact Computation of Parallel Robot''''s Generalized Inertia Matrix

According to the definition of the new hypothetical states which have obvious physical sig-nificance and are termed as no-gravity static and accelerated states, a method for exact computa-tion of the parallel robot's generalized inertia matrix is presented. Based on the matrix theory, the generalized inertia matrix of the parallel robot can be computed on the assumption that the robot is in these new hypothetical states respectively. The approach is demonstrated by the Delta robot as an example. Based on the principle of the virtual work, the inverse dynamics model of the robot is formulized after the kinematics analysis. Finally, a numerical example is given and the element dis-tribution of the Delta robot's inertia matrix in the workspace is studied. The method has computational advantage of numerical accuracy for the Delta robot and can be parallelized easily.     

静电场的描绘实验方法对比分析

通过对静电场描绘实验两种方法的对比分析，指出其优缺点，并给出提高测量精度的方法。     

Transitions in Wear and Friction of Carbon Fiber Reinforced Copper Matrix Composite Sliding Against AISI-1045 Steel

Carbon fiber reinforced copper matrix composite is anewtype of material that can be used in an unlubricatedfriction pair because it has a good self-lubricating perfor-mance in dry sliding against the steel[1 ,2].The wear char-acteristics of composites int…