基于航空运输性要求的汽车固定装置设计

特种车辆常用于公路以外的特殊使用环境如抢险救灾,需要通过航空或铁路实现远距离运输。为满足航空运输的要求,在有限元软件中建立车辆运输过程中限动卡套的仿真模型,依据国家军用标准GJB 3369-98《航空运输性要求》,做结构强度仿真分析,实现其结构优化及可靠性提升。

Study on anti-faulting design process of Urumqi subway line 2 tunnel crossing reverse fault

For the tunnel crossing active fault,the damage induced by fault movement is always serious.To solve such a problem,a detailed anti-faulting tunnel design process for Urumqi subway line 2 was introduced,and seven three-dimensional elastic-plastic finite element models were established.The anti-faulting design process included three steps.First,the damage of tunnel lining from different locations of fault rupture surfaces was analyzed.Then,the analysis of the effect on tunnel buried depth was given.Finally,the effect of the disaster mitigation method on the flexible joint was verified and the location of the flexible joint was discussed.The results show that when the properties of surrounding rock at the tunnel bottom grows soft,the tunnel deformation curve is smoother and tunnel damage induced by fault movement is less serious.The vertical displacement change ratio of secondary linings along the tunnel axis may be the main factor to cause shear damage to the tunnel.The interface between the hanging wall and fracture zone is defined as the most adverse fault rupture surface.The tunnel damage was reduced with the decrease in the tunnel buried depth as more energy was dissipated by overburden soil and the differential uplift zone of soil became more diffuse.The method of the flexible joint can reduce the tunnel damage significantly and the disaster mitigation effect of different locations on the flexible joint is different.The tunnel damage is reduced by the greatest degree when the flexible joint is located on the fault rupture surface.

Low-complexity systolic architecture for inversion

A modified extended binary Euclid＇ s algorithm which is more regularly iterative for computing an inversion in GF（2^m） is presented. Based on above modified algorithm, a serial-in serial-out architecture is proposed. It has area complexity of O（m）, latency of 5m - 2, and throughput of 1/m. Compared with other serial systolic arehiteetures, the proposed one has the smallest area complexity, shorter latency. It is highly regular, modular, and thus well suited for high-speed VLSI design.

FEM for Design of Balloon Expandable Stent for Coronary Artery Using Co-Cr Alloy

Lately, cardiovascular diseases are becoming a critical issue to human health and patients suffer from such a disease tend to be increasing throughout the world due to the changes in lifestyle. As the remedies to cardiovascular diseases, a coronary artery bypass graft surgery （CABG） and a stent implantation have been widely used. In order to achieve successful results through these treatments, a stent must fulfill the certain conditions with its design and mechanical properties. A stent must have sufficient stiffness to secure the strength of narrowed blood vessel and sufficient fatigue strength against the pulsatory motion of the blood vessel. Also its high flexibility is mandatory not to damage the vessel wall while it is being transferred to the lesion through the blood vessel. A design of stent has considerable influence upon the performance of stent. Thickness, curvature and connection method of strut are main variable factors in stent design.

Optimal design of V-type ultrasonic motor

V-type ultrasonic linear motor fabricated using a simple punching technique was proposed to utilize as an actuator of small precision machine.The stator of the motor is composed of a thin elastic body and four ceramics attached to the upper and bottom areas of the body.The ceramics have each direction of polarization.When two harmonic voltages with a 90° phase difference are applied to the ceramics,symmetric and anti-symmetric displacements will generate at the tip to produce an elliptical motion.A finite element analysis(ATILA) was conducted to simulate the motion pattern for the contact tip of the stator.To develop a model that generates the maximum displacement at contact tip,the FEM program was used for various lengths.In addition,an optimal model was chosen by considering the magnitude and shape of the displacement according to changes in frequency.The maximum elliptical displacement is shown by W2L11 model,which has a ratio of ceramic width to length of 1:5.5.However,the displacement of the contact tip is reduced by the bucking phenomenon if the ratio is larger than 1:6.

Compressor and Turbine Multidisciplinary Design for Highly Efficient Micro-gas Turbine

Multidisciplinary design optimization （MDO） is widely employed to enhance turbomachinery compo- nents efficiency. The aim of this work is to describe a complete tool for the aero-mechanical design of a radial in- flow turbine and a centrifugal compressor. The high rotational speed of such machines and the high exhaust gas temperature （only for the turbine） expose blades to really high stresses and therefore the aerodynamics design has to be coupled with the mechanical one through an integrated procedure. The described approach employs a fuUy 3D Reynolds Averaged Navier-Stokes （RANS） solver for the aerodynamics and an open source Finite Element Analysis （FEA） solver for the mechanical integrity assessment. Due to the high computational cost of both these two solvers, a meta model, such as an artificial neural network （ANN）, is used to speed up the optimization design process. The interaction between two codes, the mesh genera- tion and the post processing of the results are achieved via in-house developed scripting modules. The obtained results are widely presented and discussed.