Colloque International RILEM-A.B.E.M.

Sans résumé

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RILEM-A.B.E.M. International Symposium Brussels, August 30th–September 1st 1967

     

Monitoring the E.D.M. process by radio signals

Experimental studies are described to show that high-frequency radio observations provide a simple way to monitor the E.D.M. process and to distinguish between the effective spark and arc discharges. The paper also describes how radio frequency emitted during machining could be used to optimize the E.D.M. process.

It was found that radiation from the region of the gap between the electrode (tool) and the workpiece are significantly different when the following conditions occur: open voltage, sparking (effective machining), arcing and short circuit. However, a reliable technique was developed to monitor the rate of metal removal and machining efficiency during the E.D.M. process     

Wear and T.E.M. Studies of P.E.C.V.D. Diamond-like-Carbon Films

Diamond-like-carbon (D.L.C.) films are characterized by a low friction coefficient, a high wear resistance and a high corrosion resistance. D.L.C. films can be obtained by P.V.D., C.V.D. and duplex techniques with solid or gaseous precursors. Depending on the processing, hydrogen concentration ranges between 0 and 60%

In this study, hydrogenated D.L.C. has been deposited with a radio frequency system (13.56 MHz) onto a steel substrate. Wear was studied by pin-on-disc testing at room temperature with an alumina counterpart. Interrupted tests were carried out to go into wear mechanisms. Debris were collected after various given sliding times for transmission electron microscopy (T.E.M.) in addition to scanning electron microscopy (S.E.M.) applied to the wear tracks.     

A modification of the iteration method of M. E. Shvets

A modification of the well-known method of M. E. Shvets [1, 2] is proposed, whereupon the method becomes iterational — interpolational.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 19, No. 1, pp. 84–93, July, 1970.     

边界元与有限元的耦合法分析弹性地基梁与框架结构的协同工作

本文首先利用功的互等定理导出了弹性地基梁的四组基本解,建立了求解弹性地基梁的边界方程,进而由边界元及有限元的耦合理论对弹性地基梁及上部框架结构的协同工作进行了一系列的探讨。     

S.E.M. and castaing microprobe studies of undoped and doped polyacetylene films

Polyacetylene (CH)_x is actually a very studied material due to its remarkable semiconducting properties. In particular, its electrical conductivity increases of more than twelve orders of magnitude by doping processes. (CH)_x can be doped both p-type (e.g., with halogens, SbF₅, AsF₅) and n-type (e.g., with alkalis). We present here: i) qualitative studies, by scanning electron microscopy, on film morphology as a function of the preparation process and the dopant concentration, and ii) quantitative analysis, by Castaing microprobe, of dopant concentration profile in a cross-section of the film.     

Inelastic dynamic response of R.C. beam column joints by using B.E.M.

A BEM formulation to obtain the inelastic response of R.C. Beam-Column joints subjected to sinusoidal loading along the boundary is presented. The equations of motion are written along with kinematical and constitutive equations. The dynamic reciprocal theorem is presented and the temporal dependence is removed by assuming steady state response.     

Balancing Single Model Assembly Lines: Comments on A Paper by E. M. Dar-El (Mansoor)

In this brief note, we comment upon a statement made by E. M. Dar-El on the “computational impracticality” of a precedence matrix, enumeration method for balancing assembly lines,and show through an examination of several randomly generated, large problems, that the technique involved may indeed be quite effective in balancing assembly lines involving numerous individual work elements in a reasonable amount of computation time.