A progressive approach to predict shot peening process parameters for forming integral panel of Al7050-T7451

In this paper, a progressive approach to predict the multiple shot peening process parameters for complex integral panel is proposed. Firstly, the invariable parameters in the forming process including shot size, mass flow, peening distance and peening angle are determined according to the empirical and machine type. Then, the optimal value of air pressure for the whole shot peening is selected by the experimental data. Finally, the feeding speed for every shot peening path is predicted by regression equation. The integral panel part with thickness from 2 mm to 5 mm and curvature radius from 3200 mm to 16000 mm is taken as a research object, and four experiments are conducted. In order to design specimens for acquiring the forming data, one experiment is conducted to compare the curvature radius of the plate and stringer-structural specimens, which were peened along the middle of the two stringers. The most striking finding of this experiment is that the outer shape error range is below 3.9%, so the plate specimens can be used in predicting feeding speed of the integral panel. The second experiment is performed and results show that when the coverage reaches the limit of 80%, the minimum feeding speed is 50 mm/s. By this feeding speed, the forming curvature radius of the specimens with different thickness from the third experiment is measured and compared with the research object, and the optimal air pressure is 0.15 MPa. Then, the plate specimens with thickness from 2 mm to 5 mm are peened in the fourth experiment, and the measured curvature radius data are used to calculate the feeding speed of different shot peening path by regressive analysis method. The algorithm is validated by forming a test part and the average deviation is 0.496 mm. It is shown that the approach can realize the forming of the integral panel precisely.     

Topology optimization in lightweight design of a 3D-printed flapping-wing micro aerial vehicle

Topology optimization is an effective method to obtain a lightweight structure that meets the requirements of structural strength. Whether the optimization results meet the actual needs mainly depends on the accuracy of the material properties and the boundary conditions, especially for a tiny Flapping-wing Micro Aerial Vehicle (FMAV) transmission system manufactured by 3D printing. In this paper, experimental and numerical computation efforts were undertaken to gain a reliable topology optimization method for the bottom of the transmission system. First, the constitutive behavior of the ultraviolet (UV) curable resin used in fabrication was evaluated. Second, a numerical computation model describing further verified via experiments. Topology optimization modeling considering nonlinear factors, e.g. contact, friction and collision, was presented, and the optimization results were verified by both dynamic simulation and experiments. Finally, detailed discussions on different load cases and constraints were presented to clarify their effect on the optimization. Our methods and results presented in this paper may shed light on the lightweight design of a FMAV.     

双模块下颌式内转进气道/圆锥前体一体化布局研究

为实现三维内转进气道的内收缩流场与圆锥前体的外压缩流场的良好匹配，提出了一种双模块下颌式内转进气道/圆锥前体(Double-modules Chin Inward-turning Inlet and Conical Forebody，DCII/CF)一体化设计方法，获得一种新颖的双发并置、侧向安装的DCII/CF一体化布局。针对该布局形式，开展了DCII/CF一体化构型与传统的单模块内转进气道/圆锥前体(Single-module Inward-turning Inlet and Conical Forebody，SII/CF)一体化构型的数值对比研究。结果表明：DCII/CF一体化布局不仅为内转进气道提供了优秀的前体附面层排移效果，还有效避免了传统SII/CF布局中前体附面层与进气道内部流场之间的相互干扰。在Ma∞=6.0设计状态，DCII/CF一体化布局的进气道总压恢复系数相较传统的SII/CF布局有了显著提高，从0.403提高至0.482；但由于前体附面层的排移，该布局的捕获流量略有降低， SII/CF的流量系数为0.956，该布局则为0.917。而在非设计状态，该布局形式同样具备较好的总压恢复性能，在Ma∞=5.0与Ma∞=4.0的总压恢复系数分别达到了0.586和0.682，明显高于SII/CF的总压恢复系数0.507和0.619。     

虚拟环境系统中复杂模型的建立--3D资源在快速开发虚拟环境系统中的应用

对利用3D资源在快速开发虚拟环境系统中的方法进行了研究。在开发虚拟环境系统的过程中，复杂模型的建立是必不可少的，仅仅利用OpenGL函数编程来实现仿真是很困难的，针对该问题提出了利用3D资源进行3D文件读取和转换的两种方案，分析了虚拟环境中复杂模型的建立以及处理的基本方法，并对数控车床的仿真进行了详细介绍。     

Tunnel/predictor display with two-axis control coordination and simplification

A longitudinal-lateral control coordination and simplification concept is considered for a tunnel/predictor display, which presents the command flight path and a specified future aircraft position in a 3-dimensional format to the pilot, for improving flight path control. A basic element of the proposed concept is the generation of common longitudinal-lateral transfer characteristics of the predictor-aircraft system for the crossover frequency region. Control coordination is supported by a dynamics similarity between the longitudinal and the lateral response characteristics of the predictor position in closed-loop pilot control actions. The control coordination and simplification concept is considered to support the pilot in manual flight path control, directed at an enhancement of his control performance and at a reduction of his workload. Results from pilot-in-the-loop simulation experiments support the theoretical findings and show the effectiveness of the proposed predictor concept with control coordination.     

Flutter analysis of an airfoil with bounded random parameters in incompressible flow via Gegenbauer polynomial approximation

The effects of parameter uncertainty on the flutter characteristics of a two-dimensional airfoil in an incompressible flow were investigated through Gegenbauer polynomial approximation. The uncertain parameters, such as the linear and cubic pitch stiffness coefficients are modeled as bounded random variables with λ-PDFs (probability density functions). With the aid of Gegenbauer polynomial approximation, the two-dimensional stochastic airfoil system is transformed at first into its equivalent deterministic one. Then the Hopf-bifurcation point is determined through the equivalent deterministic system, and the onset of the flutter, together with the flutter frequency against the probability density distribution parameter and the intensity of the random variable is explored. In addition, the ranges of the peak pitch and plunge responses against the flight speed and the PDFs of the peak pitch response are obtained. Numerical results show how the probability density distribution parameters and the intensities of random parameters affect the flutter onset speed, flutter angular frequency, the upper and lower boundaries of peak responses, and the PDFs of peak responses.     

基于Pro/E软件的卫星三维建模方法的探讨

主要对基于Pro/E软件的卫星三维建模和高效率、高可靠性、低成本的总装设计方法等进行了初步的研究和探讨。     

域外刑事评议程序之比较研究

刑事评议程序是介于庭审程序和宣告程序之间的一个重要程序,它既是庭审的自然延续,又是裁判结论形成的前提和基础。然而,欲保证刑事评议程序的正常运行,刑事评议主体之独立必须得到保证;刑事评议之客体还应被全面考虑,并对其进行细化,以确保刑事评议的针对性和有效性,防止出现"估堆"现象。本文以域外刑事评议程序为对象,从评议的主体、客体等角度进行梳理,得出规律性的认识,以期对我国关于刑事评议的立法有所裨益。     

炉渣滤床技术处理亚麻生产废水

为了确定处理包头亚麻厂亚麻生产废水的设计方案，设计之前在现场进行了生产试验。在包头亚麻厂污水处理站，模拟炉渣滤床制造了3米高的炉渣滤层，滤渣从工厂锅炉房取用，将实际排放的亚麻煮漂车间、细纱车间、粗纱车间的生产废水混合后，通过炉渣滤层过滤处理，处理后出水由厂化验室和包头环保局化验。试验结果表明，处理后的排水各项指标完全达到国家排放标准。该工艺处理费用低，运行效果稳定，管理简便，具有明显的经济效益、环境效益和社会效益。     

Two years of INTEGRAL observation of the BHC IGR J17464-3213

On March 2003, IBIS, the γ-ray imager on board the INTEGRAL satellite, detected an outburst from a new source, IGR J17464-3213, that turned out to be an HEAO-1 transient, namely H1743-322. The spectral and temporal evolutions of the source were observed by INTEGRAL in different periods. Also RXTE observed the source for the first time on 2003 March 29 during a PCA Galactic bulge scan. The source flux decayed below the RXTE PCA sensitivity limit in November 2003, then in April 2004 it was again detected by INTEGRAL. On July 3, 2004 the source was again detected by RXTE/PCA at a 2–10 keV intensity of 16 mCrab and on July 7, reached 69 mCrab. Recently, a new outburst was observed on August 2005. We briefly summarise here the behaviour of the source observed by INTEGRAL from March 2003 to August 2005. The new outbursts of the source and the analysis of all the data collected (now public) give a global view of the spectral and time behaviour of this X-ray transient.