柔性铰链转动刚度计算公式的推导

柔性铰链作为无摩擦的支点有着成千上万的应用，以力学的基本公式和微积分为基础，给出了一般柔性铰链转动刚度计算公式的推导过程。在此基础上，得出了常用的直圆柔性铰链的设计计算公式，计算公式是精确的推导结果，且在表达上较迄今沿用的Paros给出的柔性铰链精确设计计算公式来得简洁，有利于柔性铰链及其机构的计算和分析。当直圆柔性铰链的切割半径与最小厚度相当时，Paros给出的简化公式存在一定的误差，这里的计算公式尤其适用于该类直圆柔性铰链。     

采用柔性铰链实现镜子的四自由度精密调整

设计了一种对镜子进行四自由度精密调整的机构.对其关键零件柔性铰链的设计进行了详细介绍;给出了单边直圆柔性铰链的刚度计算公式;应用有限元软件对柔性铰链进行了应力和变形校核.结果表明有限元分析的结果与理论计算值基本一致,由此表明所设计的镜子调整机构能够满足设计要求.     

三种形状柔性铰链转动刚度的计算与分析

本文针对3种形状的柔性铰链进行力学分析，推导出它们各自绕z轴的转动刚度计算公式；通过计算、比较和分析得出柔性铰链中外形、几何尺寸等设计参数对转动刚度的影响程度。根据分析结果确定3种形状柔性铰链各自的微制造工艺及适用场合，为MEMS中柔性铰链的设计与应用提供一定的依据。     

玻璃静疲劳性能研究

对玻璃静疲劳性能进行分析和研究。试验选用同轴双环弯曲装置,方板试件用V氏压痕裂纹来模拟玻璃中的微裂纹。将疲劳试验数据进行分析,归类,利用自编的Fortran曲线拟合程序,求得裂纹扩展参数n。采用慢裂纹增长模型来解释整个试验结果和断面．讨论试验的各个阶段及分析试验中的某些异常现象。     

Adhesion Science and Surface Analysis. Typical Examples

A number of surface modification methods using mechanical, chemical, electrochemical or physical processes have commonly been employed to treat adherend surfaces and improve adhesion in various bi- or multi-layered systems which play a key role in many advanced technologies. Results reported in this review paper deal more particularly with components of polymer-metal systems and provide typical examples of surface analysis obtained by x-ray photoelectron spectrometry (XPS), ion scattering spectrometry (ISS), low-energy electron induced x-ray spectrometry (LEEIXS), optically stimulated electron emission (OSEE) and Fourier transform infra-red spectrometry (FTIR). These examples concern, on the one hand, metallic adherends (aluminum, stainless steel, zinc-coated steel, gold) the surfaces of which were modified by cleaning, etching, oxidation, conversion or chemical grafting and, on the other hand, bonded joints (polyester-steel and epoxy-aluminum systems) which were delaminated using a peel test and a three-point flexure test, respectively.     

Development of XY scanner with minimized coupling motions for high-speed atomic force microscope

The design and fabrication processes of a novel scanner withminimized coupling motions for a high-speed atomic force microscope (AFM) were addressed.An appropriate design modification was proposed through the analyses of the dynamic characteristics of existing linear motion stages using a dynamic analysis program,Recurdyn.Because the scanning speed of each direction may differ,the linear motion stage for a high-speed scanner was designed to have different resonance frequencies for the modes,with one dominan...     

平面3自由度并联微动工作台的运动学分析

讨论了一种平面3自由度柔性并联微动工作台的运动情况。首先建立了机构的两个闭合回路,简化了Y.Yong,T.Lu和D.Handley[3]提出的3条闭合回路的模型。再根据“伪刚体模型”法建立方程,从而得到各柔性铰链的旋转角度及机构的运动情况。最后根据齐次坐标变换得到机构运动输入与输出关系,有助于得到机构的运动空间和范围。     

Effect of vegetable and synthetic fibers on mechanical performance and durability of Metakaolin-based mortars

The use of vegetable fibers has regained interest in different fields. In fact, fibers may represent an alternative to traditional fibers incorporated in building materials, such as polypropylene fibers. Sustainable development requires the adoption of ecofriendly and natural materials. In this approach, using vegetable fibers as reinforcement for cementitious materials represents an interesting option for concrete industry. Thus, this article studies mechanical performances and transfer properties of cementitious mortars reinforced with vegetable fibers. The used fibers were Dis (DS), Alfa (AF), Date palm (DP) and Hemp (HE). They were subjected to prior treatment with calcium hydroxide. The results show that reinforced mortars with vegetable fibers represent a better deformation capacity than the control mortar without fibers; the best bending strength was recorded for hemp and date palm mortars; the addition of vegetable fibers leads to thermal conductivity decrease by 15% for a content of 0.1%. However, greater carbonation depths were recorded for vegetable fibers based mixes. These findings, for us, are promising for the use of vegetable fibers in cementitious materials.     

倒圆角三角型两轴柔性支撑设计

为提高压电陶瓷驱动的快速反射镜的回转精度,对倒圆角三角型柔性支撑进行研究。首先利用卡氏第二定理推导出倒圆角三角型柔性铰链柔度和回转精度理论计算公式;然后建立倒圆角三角型柔性铰链和两轴柔性支撑的有限元模型,并进行仿真分析得出柔度和回转精度的仿真值。将仿真值与理论值进行比较,其结果表明,最大误差在8%以内,验证了所推导公式的准确性。对比直圆型柔性支撑,在保证柔度的前提下,倒圆角三角型柔性支撑的回转精度提高了40%,具有重要的工程实用价值。     

杠杆放大式双足压电直线电机的建模及优化设计

杠杆放大机构设计对于杠杆放大式双足压电直线电机的性能起决定性作用。该文分析了杠杆放大式双足压电电机的作动机理,建立了基于柔性铰链的杠杆放大机构的动力学模型,对机构放大率进行了理论计算,纵向、横向理论放大率分别为3.12和1.98。利用有限元软件进行仿真分析,理论计算与有限元仿真误差分别为3.1%、14.6%。在此基础上,利用遗传算法对杠杆放大机构柔性铰链结构参数进行优化设计,优化后驱动足纵向、横向位移分别提高了17.6%、8.1%。