Abstract: A shear strength criterion of jointed rock masses, taking the contribution of joints, the contribution of rock bridges and the contribution of undutant angle made by adjacent joints into account, is developed. Further, some phsical constrants at extreme stress levels are discussed during the shear failure process of joints and jointed rock masses. Moreover, the parameters of the criterion may he random variables, so it can be used to analyze the failure probability of random models and the risk of rock engineerings.
Abstract: It was found that the unstability was caused by the blocking of tuyere for the overdeveloped mushroom and annulus for carbon deposition produced from oil. Based on the experiment results, the reasons and Conditions about this phenomena was discussed in detail, and a qualitative account of the safe cooling operation was also presented.
Abstract: The molten iron is solidified out into white iron by using whiting elements. It changed the cooling curve of molten iron, and lost some important special points in cooling curve of thermal analysis. When the molten iron solidifys grey iron, the five special points of cooling curve can be used to forecast composition C and Si exactly. The linearity of special points is different. The other compositions and molten number affect accuracy of forecasting. This paper proposes the whitening compensation equivalent.
Abstract: By using magnetic sputtering disposition four films were made by sputtering two iron target materials and two nickel target materials on a base material (1Cr18Ni9Ti). Corrosion resistances of these films, target materials and base material mentioned above were studied in various H2SO4 concentration solutions and the pitting resistance of the film were also investigated in 0.05mol/L H2SO4 solution. It has been found from the Tafel Plots, the cyclic polarization measurements and the microscopic internal analysis that sputtered films are microcrystal organization and have better corrosion resistances including pitting resistance than the target material without sputtering.
Abstract: An elasto-plastic model for the thermal stress during solidification in strand is applied to the horizontal continuous casting of steel in Maanshan Iron and Steel Company. Calculation and analysis of the heat transfer, stress and strain for the strand have been made. The distribution of thermal stress for strand has been quantitively given. It has been indicated that because the surface reheating of stand is very large after the strand leaves the mould, the internal cracks will be formed.
Abstract: The investigation on rolling texture of commercially pure aluminium without initial texturo shows, that the orientation space, orientation distribution function, Gauss model and orientation fibre analysis are more powerful and easier methods for texture research and have many advantages. During the rolling of polycrystal aluminium the β fibre in the orientation space is the stable fibre. With increasing deformation the accumulation of grain orientations on β fibre keeps rising. The main rolling texture components are the C {112} <111>, S {123}<634>, B{110}<112> and G {110}<001>. Their stability during deformation is also analysed and discussed.
Abstract: The functions onf superalloy mechnical database system is introduced, Logical Data Structure (LDS) is used for database design. The system can collect, arrange and store variety of the mechnical feature data of superalloys, and supply varieties of output data needed. The system can supply someuseful extemsional data by means of regression treatment program in FORTRAN.
Abstract: The dual-stream functions method is improved and applied to establish the velocity field which strictly satisfies velocity boundary conditions of arbitrary caliber configurations. The rigid-plastic interface at the entrance is replaced by several planes so that the velocity discontinuity condition at the entrance is satisfied. Penalty function algorithm is applied to make the incompressibity condition be satisfied. Then, in complex caliber rolling, a general method for the simulation of three dimensional metal deformation is found and a general velocity field which can be used in arbitrary three dimensional metal flow is formulated.
Abstract: A simplified solution to the point contact elastohydrody-namiclubrication is presented in this paper. By simultaneously solving the energy equation and the surface temperature equation temperature distributions of three dimensions in contacts are obtained based on pressure and film thickness determined in calculations of isothermal EHL. A group of formulas of the maximum rise in temperature of film and contact surfaces is proposed, which has been verified by experimantal results.
Abstract: In this paper, with the method of geometric conversion, thefirst contact point and it's characteristic aagle are determined when the roller gripping the stock. At the same time, an approximate formula has been studied out for engineering application. As a result, the calculating formula of the gripping force of skew-rolling processes can be put into use.
Abstract: MESH module is developed to improve the data preparation of the SAP5 program by using the of the Finite Element Analysis programs based on micro-computer. The 2-d or 3-d node information is generated by using mesh generating. According to the input reguirements of the SAP5 program the information is edited to form a complete input file which can be accepted by SAP5 as well as the drawing data file of mesh generating is generated. The paper introduces the struction of MESH and the details of mesh generating, man-machine dialogue designs and the drawing of mesh graph.
Abstract: The growth mechanism of anodic films in the mixture of sulphuric and oxalic acids were studied. It was found that double peaks appeared in voltage-time transits during anodizing at constant current density in exalic acid with small addition of sulphuric acid. With increase of sulphuric acid concentration, the second peak gets closer to the first continuation period shortens. An adsorption competition mechanism was proposed to explain the effect of the amount of ox-alic concentration on the voltage-lime transits, the film growth rate, the hard-ness and abrasion resistance of the film. The mechanism can also explain the reason lor the appearance of the double peaks.
Abstract: In the research of corrosion electrochemical characteristics ofalloys, the transient electrochemical responds on sample surface is important, especially the potential distribution. One of the effective tool is collccted-microele-ctrode method, which is newly developed, In this method, a multi-channel data collecting system is necessary. In this paper, the structure and principle of the system is discussed.
Abstract: The activities on the boundaries of the two-phase rigion in CaO-CaF2-SiO2 ternary system at 1450℃ have been obtained by using the formula presented before and the primary data given by Xu Yuaasen. All these results can be extrapolated to the boundaries of the two-phase rigion in a binary system. This method can also be widely used for other ternary system.
Abstract: By means of X-ray diffraction, electron microprobe and mine-ralographic Lest the ingredient of Z-type mold coating used for making centrifugal cast steel pipe has been analysed. The results show that the coating consists of zircon (ZrSiO4), bentonite, oxide ferric and a little high polymer. After sintering at high temperature high polymer decomposes or volatilizes, zircon and bentonite remain in a crystal state and the grains of bentonite refine. On the surface of the bentonite a thin layer of liquid film forms and then strenth of the coating decreases.
Abstract: This paper makes use of Bellman dynamic programming principle and Lyapunov function to solve the problem of stochastic optimal stability of general stochastic system. By using this method the a determine theorem on optimal exponent stability for a class of liner stochastic system is established.
Monthly, started in 1955 Supervising institution：Ministry of Education Sponsoring Institution：University of Science and Technology Beijing Editorial office：Editorial Department of Chinese Journal of Engineering Publisher：Science Press Chairperson：Ren-shu Yang Editor-in-Chief：Ai-xiang Wu ISSN 2095-9389CN 2095-9389
