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81.
以Ti/V/Cu、V/Cu为中间层的TiAl合金   总被引:1,自引:0,他引:1       下载免费PDF全文
用真空扩散连接方法对TiAl/Ti/V/Cu/40Cr钢及TiAl/V/Cu/40Cr钢进行了研究。结果表明,以Ti/V/Cu作中间层的接头拉伸强度高于以V/Cu作中间层的接头强度。界面分析显示,Ti/V、V/Cu、Cu/40Cr钢的各个结合界面处未形成金属间化合物,而TiAl/Ti的结合界面上有Ti3Al产生;在TiAl/V的界面上有Ti3Al、Al3V两种金属间化合物产生;界面上脆性金属间化合物的产生是接头发生断裂的原因。  相似文献   
82.
碳纤维韧化涂层处理对复合材料性能的影响   总被引:1,自引:0,他引:1       下载免费PDF全文
选择高韧性环氧树脂作为碳纤维表面涂层处理剂,研究了碳纤维表面聚合物涂层韧化处理对其复合材料性能的影响,探讨了界面韧化的作用机理。结果表明:高韧性环氧涂层能提高单向复合材料的层剪、拉伸及冲击等性能,且处理工艺简单;涂层处理后Φ150mm复合材料压力容器强度转化率由81%提高到86.4%。  相似文献   
83.
介绍铝-铜复合薄板材的超声波检测方法。论述了采用界面回波相位判断法和幅度C扫描检测法确定该种复合板中脱接缺陷的要点,并对各种方法的检测结果进行了分析。  相似文献   
84.
近年来高能离子辐照引起的薄膜附着力增强现象及其应用受到了广泛的重视。由于高能离子一固体相互作用的复杂性,目前对附着力增强的物理机制的认识还不清楚。文章基于高能离子辐照引起界面原子化学结合键增强的思想,建立了薄膜附着力增强的理论模型,并由此得到辐照离子阈剂量与离子能量损失(电子阻止能力)及其界面原子结合键能的分析表达式,计算结果与实验结果很好吻合。理论分析表达式说明,膜附着力增强的阈剂量受界面原子结构、元素种类、电子阻止能力及其形成固体径迹所损失的能量等多种因素有关。  相似文献   
85.
The construction of a solar sail from commercially available metallized film presents several challenges. The solar sail membrane is made by seaming together precut lengths of ultrathin metallized polymer film into the required geometry. This assembled sail membrane is then folded into a small stowage volume prior to launch. The sail membranes must have additional features for connecting to rigid structural elements (e.g., sail booms) and must be electrically grounded to the spacecraft bus to prevent charge build up. Space durability of the material and mechanical interfaces of the sail membrane assemblies will be critical for the success of any solar sail mission. In this study, interfaces of polymer/metal joints in a representative solar sail membrane assembly were tested to ensure that the adhesive interfaces and the fastening grommets could withstand the temperature range and expected loads required for mission success. Various adhesion methods, such as surface treatment, commercial adhesives, and fastening systems, were experimentally tested in order to determine the most suitable method of construction.  相似文献   
86.
This paper deals with the modelling and simulation of aircraft systems, in particular for power transmission and control. It is intended to review, propose and disseminate best practices for making model-based/simulation-aided engineering more efficient at any phase of the system life cycle. The proposals are aimed at creating value, not only by increasing the performance of the product under study but also by shortening the time to market, capitalizing knowledge, mitigating risks and facilitating concurrent engineering. The needs associated with the engineering activities are firstly identified to define a set of requirements for the models. Then, these requirements are used to drive the considerations leading to model development, focusing in particular on the process, modelled physical effects, modelling level, model architecting and concurrent engineering. The third part deals with the model implementation, giving special consideration to the different types of models, causalities, parameterization, implementation and verification. Each part is illustrated by examples related to safety critical actuators.  相似文献   
87.
《中国航空学报》2020,33(12):3564-3574
In this paper, a novel 2-DOF rotational pointing mechanism (RPM) is designed inspired by the guidelines of the graphical approach. The mechanism integrates with a fast steering mirror (FSM) for compensating pointing errors of a laser beam. The design intends to achieve an angular travel of ±10 mrad and steers a 25 mm mirror aperture. A planar flexure with beam flexures accompanied in parallel with an axial flexure build-up mechanism configuration. Compliant mechanism-based RPM ensures high precision and compactness. Compliance characteristics are established based on the stiffness matrix method for four different planar flexure layouts. One layout with best in-plane rotational compliance is then assessed for performance sensitivity to mechanism dimension parameters and parasitic error, thus informing the design space. Rotational stiffness in both the in-plane rotational axes and stress is determined based on finite element analysis (FEA). The wire electrical discharge machining (EDM) is employed for developing the proof of concept for the RPM and is then assembled in FSM. Experiments are conducted to determine the rotational stiffness and angular travel about both in-plane rotational axes. Comparison among theoretical, numerical and experiments reveal excellent linearity of rotational stiffness along the rotational travel range. The maximum theoretical error is less than 5.5% compared with FEA while, the experimental error has a mean of 5% and 3% for both rotational axes thus satisfying the intended design requirement.  相似文献   
88.
针对传统金属探测方法的缺点,提出数字电感探测法。基于电涡流原理,采用先进的数字电感转换器LDC1000做为传感器,通过前端自制印制板电感线圈检测金属,通过计算将测量结果转换为数字量,经串行外设接口(以下简称SPI)与高性能ARM处理器Cortex-M4相连,可实现高速、高精度金属测量。实测结果表明:本传感器克服了传统电感测量方法抗干扰能力差、模拟接口、精度低的缺点,实现了数据采集的高速、可靠,并使测量精度提高到亚微米级,可实现对金属物距离、角度、运动、位移、压缩等的高精度测量。  相似文献   
89.
指挥调度ISDN数字用户接口设计   总被引:1,自引:0,他引:1  
提出指挥调度系统数字用户接口的实现方案,详细介绍了2B D接口的软硬件设计方法,为开发新型、全数字、大容量的指挥调度系统做了充分的技术准备。  相似文献   
90.
基于从事COM相关开发和研究的实际经验,本文对于Microsoft公司和Borland公司对于Sparse V-Tables的处理方式进行了研究和实验,并提出了解决此类意外AV问题的方法.  相似文献   
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