Plane steady vibration of an elastic wedge

The problem of plane steady vibration of an elastic wedge of arbitrary angle (less than 180 degrees) subject to harmonic normal and shearing tractions on its faces is reduced to a system of singular integral equations by the superposition of two half-plane solutions. The integral equations have kernels with Cauchy singularities of a non-translation type, except for the 90 degree wedge. The locations of these singularity lines are shown graphically as a function of wedge angle.     

GPS误差模型参数估计的Hopfield神经网络方法

本文首先建立了ＧＰＳ误差模型。然后，利用Ｈｏｐｆｉｅｌｄ神经网络（ＨＮＮ）方法对误差模型参数进行了估计，并给出了其硬件实现方法。将估计结果与传统的最小二乘（ＬＳ）估计进行比较，证明了神经网络方法的有效性。     

Regularity of Potential Functions of the Optimal Transportation Problem

The potential function of the optimal transportation problem satisfies a partial differential equation of Monge-Ampère type. In this paper we introduce the notion of a generalized solution, and prove the existence and uniqueness of generalized solutions of the problem. We also prove the solution is smooth under certain structural conditions on the cost function.     

Torsional buckling of an elastic thick-walled tube made of rubber-like material

The elastic stability of a rubber-like, thick-walled tube which is subjected to finite torsional deformation is investigated both theoretically and experimentally. The analysis is based on the theory of finite elastic deformations, in cojunction with the method of small displacements superposed on large elastic deformations. The governing field equations are solved by a numerical scheme which determines the critical buckling torque and the associated buckling mode of the tube. The predicted results compare closely with the experimental measurements of the buckling of thick-walled silicone rubber tubes tested under finite twist.     

有限元法在三轴转台机械系统设计中的应用

本文探讨了三轴转台机械系统的设计与计算问题，以惯性三轴测试转台和三轴模拟台为例，确定了多种运转状态下的有限元法计算模型，并对其进行了静、动态特性计算，比较分析了计算结果，为合理结构的设计提供了重要数据，说明了在三轴转台机械系统设计中有限元法的重要性     

Stoßwellen in Gas-Partikel-Gemischen mit Massenaustausch zwischen den Phasen

Zusammenfassung Die Nichtgleichgewichts-Austauschprozesse, die in einem Gas-Partikel-Gemisch hinter einer Stoßwelle ablaufen, werden in dieser Arbeit untersucht. Sie werden sowohl mit den Erhaltungsgleichungen für zwei interaktive Kontinua als auch mit den vereinfachten Gleichungen für Einzelpartikel in einem Gaskontinuum beschrieben. Der besondere Akzent liegt auf den Transportvorgängen sehr kleiner Partikel, die im Übergangsbereich zwischen Kontinuumsbedingungen und freier Molekülströmung stattfinden. Sie werden durch einfache Knudsenzahlansätze berücksichtigt. Beispiele zeigen die Geschwindigkeits-, Temperatur- und Partikelgrößenrelaxation hinter Stoß-wellen in Argon mit DOP-Tröpfchen und mit festen NaCl-Salzpartikeln.

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Shock waves in gas-particle mixtures with mass transfer between the phases

The nonequilibrium transfer processes, which take place in a gas-particle mixture behind shock waves, are investigated in this study. They will be described both by the conservation equations of two interactiv continua and by the simplified equations of a single particle in a gas continuum. The special accent is on exchange processes of very small particles, which take place in the transition regime between continuum and free molecular conditions. They are taken into account by simple Knudsen number corrections. Examples show the velocity, the temperature and the particle size relaxation behind shock waves in argon containing DOP droplets or solid NaCl particles.

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Die Arbeit entstand im Rahmen des Sonderforschungsbereiches SFB 209 Stoff- und Energietransport in Aerosolen der Universität — GH — Duisburg. Die Autoren danken der Deutschen Forschungsgemeinschaft für die finanzielle Unterstützung     

结构优化设计的KFD方法及其在电除尘器本体结构优化中的应用

电除尘器本体结构优化设计是一个规模大,设计变量数多而具有相当难度的几何可调和拓扑可调优化设计问题。对这样一个大型复杂的结构优化问题,本文在文[1]的工作基础上,充分利用结构的力学特性,应用有效设计变量的概念,建立了不用求偏导数且不必解线性规划的可行方向法—KFD方法。该方法具有收敛速度快、占用内存少的优点,比通常ε有效约束可行方向法提高速度数十倍。实际应用的结果表明文中的方法是很有效的。     

DYNAMIC SIMULATION ANALYSIS OF CAPTURE AND BUFFER SYSTEM BASED ON CLAW-TYPE DOCKING MECHANISM

现有在轨服务的对接机构由于其尺寸大、结构复杂、对接目标单一等局限性因素,无法很好地为后续我国探月工程任务提供有力支撑,且受限于运载能力,对接机构的轻量化也是必不可少的一项环节.为研究可服务于未来月球空间站以及载人登月等高轨道任务的对接机构,设计了一种新型抱爪式对接机构,其采用异体同构周边式构型,可以实现主/被动飞行器之间的互换.利用 V 型槽与爪钩等结构部件实现飞行器对接过程中的捕获以 及能量消耗功能,从而实现两飞行器之间的稳固联接.该对接机构具备尺寸小、重量轻、结构简单、功能易实现等优势. 对其捕获缓冲系统进行了动力学分析,计算了缓冲元器件的参数对其捕获性能的影响,在 ADAMS 完成了数字虚拟样机的建立,结合实际两种典型的对接初始条件工况进行了仿真研究.研究结果表明,两种工况下的对接过程能量消耗满足设计要求,能够以较小的 V 型槽的碰撞力完成捕获,结果证明了捕获缓冲系统的可行性以及该构型对接机构具备较好实现任务的能力.     

Shear flow over a rotating plate

A shear flow interacts with a rotating boundary. The three dimensional Navier-Stokes equations reduce to a set of ninth order, nonlinear, ordinary differential equations which are partially decoupled. Universal similarity velocity profiles are found by numerical integration. If the shear is high enough, reverse flow occurs and the mean drag may be negative. The solution is a rare exact similarity solution of the Navier-Stokes equations.