共查询到19条相似文献,搜索用时 265 毫秒
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对于纳米压入法,在加载过程中,压头尖与试样表面的初始接触点必须判断准确,初始接触点判断的精度将对测量结果产生很大的影响.本文利用西安交通大学精密工程研究所研制的微力微位移测试仪,对初始接触点判断的相关问题进行了深入研究.在压头尖与试样表面接触前,由电容测微仪测得的位移值是加载装置空载下的输出值;而当压头尖与试样表面接触后,压头与试样之间将产生作用力,使电容测微仪的测量值偏离加载装置空载下的输出曲线趋势.分别用一直线和一多项式曲线对压头无载荷和有载荷作用时测得的电压位移曲线进行拟合,拟合直线和曲线的交点即可作为初始接触点.大量的实验表明,运用上述方法可使初始接触点的判断精度在±10nm. 相似文献
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测量多层膜结构中薄膜厚度的一种新方法 总被引:2,自引:1,他引:1
提出一种基于平行板电容测微原理进行多层膜材料的测厚方法。该方法用有效电极直径西3mm电容传感头,通过变化空气隙△h进行多次测量,对输出电压V值进行线性拟合,得到空气隙与测量电压的关系,计算出被测厚度,测量精度达0.01μm。若采用有效电极直径西1mm传感头,测量精度可达0.001μm。通过理论分析和实验证实,该方法不需对被测材料提前标定相对介电常数,不需特殊制备样件,是非接触测量,测量方法简单、成本低。因此适用于各种薄膜、特别是多层结构膜的无损膜厚测量及平面度测量。 相似文献
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材料微观力学性能测试以纳米压痕和划痕最具代表性,通过连续记录载荷-深度关系曲线,进而分析获取被测材料的硬度、弹性模量及粘附性等参数。该文提出一种压头固定,试件运动的纳米压痕加载装置,以压电叠堆驱动、柔性铰链传动,实现压入与压出过程。首先讨论了两种用于纳米压痕/划痕的直角式柔性铰链方案,进行了静力和模态分析;其次对精密加载单元进行具体结构设计和有限元分析;最后试制了加载装置样机并进行压痕实验。研究结果表明,该装置可较准确测取材料硬度,且具有较好的稳定性。 相似文献
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为了研究单晶SiC的微观力学性能和加工方式,开展了单晶6H SiC(0001)的微纳米压痕试验,并采用ABAQUS软件对纳米压痕过程进行了数值仿真及完成了试验验证。结果表明,单晶SiC在加载阶段的变形机理与压入载荷无关;硬度和弹性模量表现出了明显的尺寸效应;球形压头作用下的应力值最小,玻氏压头和维氏压头作用下的应力值相同,大于圆锥压头的应力值;压痕裂纹类型有主裂纹、侧向裂纹、主次型裂纹、平直型裂纹、间断型裂纹,裂纹的平均长度随着加载力的增加而逐渐增加。 相似文献
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微小位移测量在工业控制、机械制造等领域应用广泛。本文提出了一种基于电压积分翻转电容法的微位移测量方法,该方法利用平行板电容器充放电的特性,使输出电压根据电容的不同容值而发生周期性的反转,产生相应频率的输出波形。该系统由位移测量电极板、电压积分翻转电路、低通滤波电路和MCU模块组成。位移测量电极板位移变化时其电容发生相应改变,电压积分翻转电路将电容变化值转化为输出信号的频率变化值。低通滤波电路将输出信号滤波,降低高频噪声的影响。MCU模块计算出频率变化值对应的微小位移变化值。实验结果表明:由线性回归分析,基于电压积分翻转电容法的微位移测量,其线性度误差为2.16%,相对误差为0.06%,与其他基于电容的位移测量方法相比,线性度误差比基于电容式传感器的微位移测量法小0.09%,比ZNXD型电容式传感器位移测量法小0.64%;相对误差比基于电容式传感器的微位移测量法小0.26%,比ZNXD型电容式传感器位移测量法小0.14%,比平板式电容器位移测量法小0.36%。相比之下,本文的具有较好的线性度误差和相对误差。 相似文献
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设计了一种复合模式界面开裂测试装置,通过改变加载臂长来实现作用在试样裂纹尖端的不同应力模式。以试验测得的临界载荷及对应位移、裂纹扩展长度为条件,建立与测试装置对应的有限元模型,计算裂纹尖端模式角及在此模式角下的临界能量释放率。结果表明,装置所测试的模式角为7°~78°,以此为参数,可预测微电子封装界面强度。 相似文献
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压电陶瓷微位移特性的电脑接触式干涉测量法 总被引:5,自引:1,他引:4
介绍了压电陶瓷微位移器的工作原理,在此基础上提出了一种用由立式接触式干涉仪改造的电脑接触式干涉仪测量微位移特性的方法。其完善的测试软件系统,实现了对压电陶瓷微位移量的自动化、智能化精密测量。并对自行设计的压电陶瓷微位移装置进行了测试,得出电压-位移的关系曲线和迟滞曲线,精度和重复性值达0.01μm。 相似文献
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为了进一步减小基于相位凝固技术的激光反馈干涉系统测量运动物体微位移时的测量误差,采用MATLAB数值仿真及曲线拟合的方法,对移相间隔和外腔反射面振动幅度引起的系统误差进行了理论分析。在系统实验中依据相位凝固原理对物体运动产生的干涉信号进行采样,获取多组光功率曲线,在光功率曲线上实时判向并标记特征点。根据特征点重构被测物体的微位移曲线,对重构得到的微位移台阶曲线进行多项式拟合以提高测量精度。结果表明,在固定移相间隔为/5、激光器波长为1550nm的情况下,测量分辨率优于/20(77.5nm),实际测量的绝对误差最大值为47.98nm,峰峰值误差平均值小于1nm。相位凝固技术调制解调干涉信号为微位移的方向辨识和高精度测量提供了新的解决方案。 相似文献
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Roland Biberger Guenther Benstetter Holger Goebel 《Microelectronics Reliability》2009,49(9-11):1192-1195
In this study a displacement current capacitance sensor (DCCS) for scanning capacitance microscopy (SCM) is introduced. It can be used for both intermittent contact (IC) and contact-SCM operation. Based on I/V conversion and subsequent lock-in amplification a displacement current can be detected and used as a measure for dopant concentration. Therefore a periodic variation of the AFM tip substrate capacitance is required. This can be achieved either by a periodic tip oscillation (IC-SCM) or an applied AC voltage between tip and sample (contact-SCM). The advantage of the DCCS is the linearity, which makes it possible to detect absolute dopant concentrations. 相似文献
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M.L. Chan Francis E.H. Tay V.J. Logeeswaran K.Y. Zeng Lu Shen F.S. Chau 《Analog Integrated Circuits and Signal Processing》2003,37(1):45-56
A rapid and accurate static and quasi-static method for determining the out-of-plane spring constants of cantilevers and a micromachined vibratory sensor is presented. In the past much of the effort in nanoindentation application was to investigate the thin-film mechanical properties. In this paper, we have utilized the nanoindentation method to measure directly some micromachined device (e.g. microgyroscope) spring constants. The cantilevers and devices tested were fabricated using the MUMPS process and an SOI process (patent pending). Spring constants are determined using a commercial nanoindentation apparatus UMIS-2000 configured with both Berkovich and spherical indenter tip that can be placed onto the device with high accuracy. Typical load resolution is: 20 N to 0.5 N and a displacement resolution of 0.05 nm. Information was deduced from the penetration depth versus load curves during both loading and unloading. 相似文献
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《Mechatronics》2020
Soft robots and manipulators with inflatable links possess inherent safety characteristics that make them a very interesting choice for tasks requiring human-robot interaction. However, they may face important challenges in their performance due to low structural stiffness. Accurate positioning of the end effector may prove a difficult task due to limitations in gravity compensation, or due to the occurrence of oscillations during motion, especially in the absence of precise information about the payload that is being manipulated. In this paper a novel approach to the design and control of a robot with an inflatable link is proposed, where the link assumes the triple role of compliant structural element, touch sensor, and active mechanism to adjust the performance of vibration control algorithms. For this, a vision sensor is placed inside the link to provide information about the structural deformation. The sensor is used to measure the tip displacement, and also to detect contact of the link surface with the surrounding environment. The concept was implemented on a two-joint rigid manipulator with a single inflatable link. Experiments on vibration control and contact detection of the inflatable link are reported where the control system was able to significantly reduce tip oscillations, including when a payload was added to the tip. The robot was also able to make binary detection of contact between the inflatable link and the user, and change its operation mode accordingly. 相似文献
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Young Ok Lee Minseok Jang Wongoo Lee Choong Woo Lee Chung Choo Chung Young Seop Son 《Mechatronics》2011,21(7):1156-1162
In this paper, we present a novel control method with clamping force estimation for an electric parking brake system. This simple control structure can be implemented at low cost as it does not require a clamping force sensor. The characteristic curve is conventionally used to estimate the clamping force through the angular displacement of the DC motor; however, this can result in error because of the dependence of the curve on the brake clearance between the brake pads and brake disk at release. We solve this problem by approximating the initial contact point using the angular velocity of the motor. We then propose a novel on–off control method to avoid excessive clamping forces by predicting the additional angular displacement after power-off caused by the inertia effect. Finally, we experimentally validate our proposed control method. 相似文献
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面向大型薄壁构件自寻位加工检测一体化测控原理,研发了一种小型化多维压电力传感器并进行标定研究。分析静态标定时,偏载对压电传感器多维力测试精度的影响。通过对静态标定加载有偏差时传感器受力的理论推导得到,加载偏差使传感器的转换系数改变,导致向间干扰补偿系数失真,影响了横向干扰输出,降低了测试精度;分析了偏载程度对传感器测试精度的影响,提出了衡量加载点偏差程度的判别方法,发现微小加载偏心带来的附加干扰会超出传感器自身向间干扰指标规定的5%;针对机械连接偏载不可避免事实,找到了克服偏载对转换系数影响的输出比例归一化法,将向间干扰降到5%内。 相似文献
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