Research on force-sensing element's spatial arrangement of piezoelectric six-component force/torque sensor

This paper proposes a novel piezoelectric six-component force/torque sensor with four-point supporting structure, and makes research on force-sensing element's spatial arrangement of the novel sensor. Two kinds of different spatial arrangements are advanced, lozenge and square arrangement. The mathematical models are built and calculated. The influence on using performance of the two kinds of different spatial arrangements of the sensor is analyzed by FEM (ANSYS software). In order to investigate the validity of the proposed method, a prototype of piezoelectric six-component force/moment sensor is developed with two kinds of different spatial arrangements, and characteristic tests of the piezoelectric six-component force/moment sensor are performed. The test shows that both of the different spatial arrangement sensors could be used to measure six-component force/torque, but the square arrangement piezoelectric six-component force/moment sensor is more suitable for measurement of six-component force/torque on axis. The interference errors of square arrangement sensor are less than 5%, which are lower than those of the lozenge arrangement sensor. The natural frequencies in six directions are analyzed and discussed.     

SSJ1200/2×200型伸缩带式输送机设计

介绍了SSJ1200/2×200型伸缩带式输送机工作特点及其设计计算过程,并通过对其设计过程的详细阐述,从而反映了皮带机在工作过程中的特性并为其制造提供了理论依据。     

小型振动电容式静电传感器的设计

文中介绍了一种基于振动电容式静电传感器的设计原理,以S08处理器为控制核心,利用静电场对电荷产生静电场力以及振动电极在激励电压下产生虎克弹力的合力作用下建立了数学模型,在经过对原始信号的运算放大,A/D转换以及嵌入式μC/OS多任务操作系统的管理下,提高了单片机的工作效率.通过将被测物理量可以转化为微弱电流变化的特点,实现了以非接触式的测量方法来标定所在区域的静电场强度.     

斜置变截面抛物线坡拱桥的内力计算

本文简要介绍了斜置坡拱桥的计算方法,给出了正拱斜置变截面抛物线无铰坡拱桥,在水平荷载分量作用下,主拱内力影响线的闭式解,为该类型坡拱桥的设计计算提供了方便。     

静定平面刚架剪力图和弯矩图画法研究

针对静定平面刚架剪力图和弯矩图常用绘制方法,如方程式法、简捷法及叠加法等,存在计算量大、比较抽象、易于出错等缺点,根据荷载、内力之间的微分、积分关系,分析荷载形式、大小与剪力图、弯矩图的曲线形状、数值之间的关系,编制了剪力图和弯矩图的绘制口诀,据此,做到直观、快速、准确绘制静定平面刚架的剪力图和弯矩图。     

支挡结构中锚杆(锚索)极限抗拔力研究

该文以支挡结构中锚杆(锚索)为研究对象,介绍了现有锚杆(锚索)抗拔承载力计算方法,分析了统一强度理论的锚杆(锚索)极限抗拔力计算方法,并作了在实际工程中应用算例的分析,进一步明确了影响支挡结构中锚杆(锚索)极限抗拔力的因素及力学状态,为支挡结构在工程建设中的设计与施工提供参考。     

Numerical investigation of the drag closure for bubbles in bubble swarms

The present paper describes an Euler–Lagrange model utilizing a drag closure derived from direct numerical simulations (front-tracking model) for (i) single isolated bubbles and (ii) bubbles rising in bubble swarms, expressed as a function of the local gas fraction. The model is applied to the prediction of an air/water system in a bubble column and for which experimental data is available. The effect of variation in size of the mapping window for the interphase coupling between the Eulerian and Lagrangian framework is investigated for both closure relations. It is found that the drag closure as a function of the local gas fraction is an improvement over the use of the drag closure for isolated single bubbles for the prediction of bubbly flow.     

轿车子午胎聚酯胎体胶配方的研制

聚酯帘线是取代人造丝帘线用于轿车子午胎体的理想材料,但在胶料配方设计时必须解决聚酯帘线的降解和与胶粘合力较低等问题。     

溶液中金刚石晶体生长的第三种驱动力

溶剂作用下金刚石晶体生长的驱动力通常有两种。它们分别取决于过剩压和温度差。但金刚石烧结体中出现的异常粒成长现象却不能用这两种驱动力来解释。介绍和分析了自己实验结果的主要规律和典型例证,说明金刚石微粉与粗晶粒之间的表面自由能之差是异常粒成长的驱动力,提出利用这种驱动力来生长金刚石大单晶的设想,并对这种驱动力在天然金刚石生长过程中的作用进行了讨论。