等离子喷涂的陶瓷涂层的特性

测量分析了三种等离子喷涂的陶瓷涂层 (Al2 O3 、Cr2 O3 、Cr3 C2 +NiCr)的显微组织、孔隙率、显微硬度及结合强度等性能 ,并通过吹砂试验对三种涂层的抗磨损性能进行了比较。结果表明 ,在抗冲蚀磨损方面 ,Cr2 O3 陶瓷涂层优于Al2 O3 及Cr3 C2 +NiCr涂层。     

陶瓷生产车间工艺布置图的CAD系统

本文以AutoCAD为图形核心系统，用C语言开发出了一套陶瓷生产车间工艺布置图的CAD应用软件．文中重点讨论了图形数据库的建立及管理方法，并对图块的存储、删除、检索等库操作功能作了介绍．另外，为了方便用户使用，系统还建立了汉化的人机交互界面，设置了幻灯演示、草图绘制等辅助功能．     

钢筋混凝土的粘结强度理论

从能量原理出发，把钢筋混凝土看成为一种纤维增强复合材料，利用已有的实验回归公式，推导出了钢筋混凝土中钢筋与混凝土的脱开条件，给出了钢筋的拔出长度与拔出载荷的关系。     

A pseudo dual-cavity extrinsic fibre Fabry-Pérot interferometric vibrometer

An extrinsic fibre Fabry-Pérot interferometric (EFFPI) sensor for the measurement of velocity and displacement of a vibrating target has been demonstrated in this work. It operates on the principle of a pseudo-double cavity within a single interferometric or “sensing” arm which, in addition, provides a sense of direction of the moving target. This has been made possible by the introduction of a birefringent film positioned along the optical path between the sensing fibre end and the intended target. Two sets of interference signals are thus propagated and detected along one fibre arm to give robust and repeatable displacement–velocity information which have been found to be relatively independent on other external effects such as minor temperature changes. The sensor has been found to be capable of measuring the desired velocity information of an inclined target while typical excitation frequencies investigated ranged from 2 to 60 Hz. In addition, two sensor configurations have been studied, one based on “conventional” optical fibres at 780 nm while the other employs a polarisation-maintaining (PM) (PANDA type) fibre as the sensing arm and operates at 1310 nm.     

Fabrication process of open surfaces by robotic fibre placement

Composite materials are being used extensively in many industrial sectors. They offer excellent material properties compared to other structural materials available. However, the traditional fabrication process using manual hand lay-up is time consuming and labour intensive. Therefore, robotic fibre placement has been introduced to overcome these drawbacks. This approach may greatly reduce cycle time and manufacturing costs. This paper describes the overall strategy for the establishment of a flexible robotic fibre placement technique. The fabrication process planning of this new technique is presented. Three different types of fibre placement for open surfaces are discussed. These include simulation-based fibre path generation, fibre steering, and sensory-based contour following methodologies. The system architecture for the process control is also presented.     

Diffuse transition and piezoelectric properties of Pb[(Zr1−xTix)0.74(Mg1/3Nb2/3)0.20(Zn1/3Nb2/3)0.06]O3 Ceramics

In this work, the piezoelectric ceramic system of Pb[(Zr_1−xTi_x)_0.74(Mg_1/3Nb_2/3)_0.20(Zn_1/3Nb_2/3)_0.06]O₃, 0.47≤x≤0.57, with composition close to the morphotropic phase boundary, was studied. From the results of X-ray diffraction and piezoelectric measurement, ceramics near x=0.51 were found at the morphotropic phase boundary (MPB) between the tetragonal and pseudocubic perovskite. The planar coupling factor (k_p=0.72) is high at compositions near the MPB, but the mechanical quality factor (Q_m=75) is low. The calculation of the diffuseness of phase transition shows that the region of phase coexistence of this system is broader than that of the ternary system.     

高压架空线路应力测试的光纤传感系统

近年来，光栅传感器的应用得到了很大的发展。本文主要论述了光栅传感系统在电力领域的应用，采用波分／时分复合技术同时检测应力等其他参数。     

Processing of alumina and zirconia nano-powders and compacts

Magnesia–doped alumina and yttria–doped zirconia nano-powders were synthesized using sucrose as a chelating agent and template material from the aqueous solutions of aluminium nitrate, magnesium nitrate, ytrrium nitrate and zirconyl nitrate, respectively. Synthesis parameters were optimized with varying sucrose to metal ion ratio, calcinations time, and temperature to produce these nano-powders. As-synthesized powders were characterized by room temperature X-ray diffraction, BET surface area analyzer and transmission electron microscopy. Y₂O₃–ZrO₂ nano-powders had particle size in the range of 80–200 nm with specific average surface area of 119 m²/g and for MgO–Al₂O₃ powders, particle sizes were 30–200 nm with the specific average surface area of 250 m²/g. Our results indicate that this synthesis method is a versatile one and can be applied to a variety of oxide-based materials to form nano-powders. Nano-powders were compacted uniaxially and densified in a muffle furnace. Sintered discs were used for hardness testing and density measurements, as well as for microstructural characterization.     

Modelling of Bird Strike on an Aircraft Wing Leading Edge Made from Fibre Metal Laminates – Part 2: Modelling of Impact with SPH Bird Model

Fibre Metal Laminates with layers of aluminium alloy and high strength glass fibre composite have been reported to possess excellent impact properties and be suitable for aircraft parts likely to be subjected to impacts such as runway debris or bird strikes. In a collaborative research project, aircraft wing leading edge structures with a glass-based FML skin have been designed, built, and subjected to bird strike tests that have been modelled with finite element analysis. In this second part of a two-part paper, a finite element model is developed for simulating the bird strike tests, using Smooth Particle Hydrodynamics (SPH) for modelling the bird and the material model developed in Part 1 of the paper for modelling the leading edge skin. The bird parameters are obtained from a system identification analysis of strikes on flat plates. Pre-test simulations correctly predicted that the bird did not penetrate the leading edge skin, and correctly forecast that one FML lay-up would deform more than the other. Post test simulations included a model of the structure supporting the test article, and the predicted loads transferred to the supporting structure were in good agreement with the experimental values. The SPH bird model showed no signs of instability and correctly modelled the break-up of the bird into particles. The rivets connecting the skin to the ribs were found to have a profound effect on the performance of the structure.