军用多媒体通信

本文主要介绍军用多媒体通信网络的系统要求、网络结构和链路结构、网络寻路和网络模拟以及多媒体技术对增强军事通信网络的抗毁性所起的重要作用。     

Finite shear-band buckling of a fiber-reinforced slab

Summary An equilibrium solution was obtained for the finite shear-band buckling of a fiberreinforced slab under axial compression, using the idealized theory of continua with the kinematical constraints of incompressibility and inextensibility. It was found that the critical buckling load wasGH, the infinitesimal shear modulusG times the thicknessH of the slab. The solution, involving discontinuities in deformation gradients at the shear-band edges, was proven to conform of the dissipation inequality (under a certain restriction on the material response), which implies the energetical admissibility of the solution obtained. Furthermore, compression tests of beechwood blocks proved that their buckling patterns of shear band type were similar to the theoretical ones. The experimental and theoretical load-shear curves showed good agreement.With 6 Figures     

Forecasting compensatory control (FCC) of machining flatness

Forecasting Compensatory Control (FCC) was implemented to improve the flatness of three dimensional prismatic workpieces in an end-milling operation. The basic logic of the strategy is based on inprocess error measurement, stochastic modelling, and prediction and compensation of the cutting errors.The proposed FCC system consisted of a newly developed laser-based in-process flatness error measurement system, a hydraulic positioning servo system, and a digital microcomputer control system. Through the application of the FCC system to on-line cutting experiments, the workpiece flatness error was reduced by up to 80% during machining.