1992, 14(4). DOI: 10.11835/j.issn.1674-4764.1992.04.001
Abstract:In this paper, the finite element method(FEM) is carried out for the contact pressure under circular foundation with visco-elastoplastic model and a 8 node finite element program determing parameter. In order to prove the reliability of the theoretical analysis, a circular rigid loading plate test on remolded clay is done. Otherwise, a comparison of the measuring contact pressure under box foundations of highrise buildings in Beijing and Shanghai with the calculated value by different method is made. The result shows the calculated value by the method proposed in this paper is more coincident with practical data.
Dai Guoxin Li Jihua Xia Zhengzhong
1992, 14(4). DOI: 10.11835/j.issn.1674-4764.1992.04.002
Abstract:For design purposes, this paper presents performance coefficients for steel structures of tall building, and furthermore design values of strength of heavy plates. The calculated results show that suggested coefficients meet the requirements of probabilistic limit states design method. They can serve as a supplement to GBJ17-88 and the expression of limit states design provided in this paper is available for reference in compilation of concerned standard.
1992, 14(4). DOI: 10.11835/j.issn.1674-4764.1992.04.003
Abstract:Moment slope displacement equations of beams with two end semirigid connection restraints are covered. The evaluation of column effective length factor both braced frames and unbraced frames with flexible joints is derived. Determination of column effective length method proposed herein is. exactly the same as those of rigid frames which was well established in Chineses Specification of Steel Structures, however, the restraining stiffness of girders to columns should be amended semirigid connection is applied.
Liu Xianying Li Shenghe Huang Zhenyi Wang Houhua Lu Jun
1992, 14(4). DOI: 10.11835/j.issn.1674-4764.1992.04.004
Abstract:This paper is a comprehensive report about the research of high efficient energy-saving ammonia air cooler. In the paper, it is introduced that the test of two-side long V-groove finned pipes which are fit for the evaporators of ammonia air coolers, optimum experiments of the finned pipes, and field experiments of contrasting the model machine with the old one in a cold storage. The result shows that the air-side heat transfer performance coefficient and the overall heat transfer performance coefficient of the two-side optimum long V-groove finned pipes are higher from 18.25% and 12.85% than those of conven tional rectangular plain-plate finned pipes respectively. At last, it is introduced the structure design of the high efficient energy-saving air cooler. Used by a few of units, it is proved that this type of air cooler has characteristics of compact structure, less floor area occupied, high heat transfer efficiency, convenient maintenance and management, and is of notable economical effect.
1992, 14(4). DOI: 10.11835/j.issn.1674-4764.1992.04.005
Abstract:本文介绍了一种测量天空亮度分布的新方法。这种方法利用视场角为180°的鱼眼镜头照相机和计算机数字图像处理系统,实现了天空亮度分布的瞬时测取和胶片密度的高效率处理。文中论述了胶片灰度与天空亮度的标定转换实验方法。引用了误差理论中的数据处理方法确定出二者间的函数关系。通过对昆明和重庆地区晴和阴天空下大量实测结果的误差处论和分析,得到了其相关系数和标准偏差的频数分布图,由此证明了这种方法的可靠性。
1992, 14(4). DOI: 10.11835/j.issn.1674-4764.1992.04.006
Abstract:In this paper,the four-moment reliability analysis method for perfopmance function implicit structure is discussed. Discrete formulas expressed by Gauss-quadrature are presented when determine the parameter of probability density function which is established based on maximum entropy theory. The method in this paper is proposed for performance function implicit structure. Particularly, the discrete formulas used in this paper largely reduce calculating work with the same precision, so that the time-consume problem of four-moment reliability anlaysis is solved.
1992, 14(4). DOI: 10.11835/j.issn.1674-4764.1992.04.007
Abstract:This paper solves the geometrically nonlinear problems of symmetric, cross-ply laminated anisotropic rectangular plates subjected to uniformly distributed load by the higher-order shear deformation theory and taking an advantage of the perturbation and the weightedresidual method. First, with the help of the perturbation, the nonlinear partial equations have been changed into linear ones. This paper can solve these linear ones by the weighted-residual method. The combination of quintic B-spline functions are chosen as the basis of trial function and Dirac delta functtion, the weighted function. The method used in this paper is simple, direct and efficient. The numerical results show a good convergence and they are in good agreement with the available data.
1992, 14(4). DOI: 10.11835/j.issn.1674-4764.1992.04.008
Abstract:Gross product of construction industry is total outcome by construction and production of construction industry. This paper analyes and fully evaluates the function and character of gross product of industry and puts forward the necessity and detailed suggestion of reforming the statistics method of gross product of construction industry according to the needs of theroy and practice.
1992, 14(4). DOI: 10.11835/j.issn.1674-4764.1992.04.009
Abstract:混凝土结构设计规范(GBJ10—89)增加了圆形截面偏心受压构件正截面强度计算公式。本文把计算圆形截面的配筋问题视为求解数学方程组问题,分析了α和As的函数关系及变化规律,采用分区间逐次逼近法求解α和As,可获得精度很高的计算结果。按同样思路,结合As的初值估算公式,可得到圆形截面配筋计算的手算方法。
1992, 14(4). DOI: 10.11835/j.issn.1674-4764.1992.04.010
Abstract:Based on Karman's nonlinear foundamental differential equations, the new method combines perturbation method with integral equation method is forward to solve nonlinear bending of a clamped circular plate on Pasternak foundation under a concentrated load at the center. This method is simple and easy to use. The numerical results show that the present solution is reliable.
1992, 14(4). DOI: 10.11835/j.issn.1674-4764.1992.04.011
Abstract:On the basis of analysing problems of conventional fuzzy controller in the design of the structure and algorithm, this paper puts forward a kind of control algorithm that is fuzzy and Adaptive PI coordinate decision controller (FACDC) . It adopts the hierarchial control structure imitating intelligent control and combines fuzzy controller and adaptive PI controller. It takes full advantage of two controllers. Since the algorithm of FACDC in model reference fuzzy adaptive algorithm, it avoids the complexity of conventional adaptive algorithm.
1992, 14(4). DOI: 10.11835/j.issn.1674-4764.1992.04.012
Abstract:In this paper, the concept of basic for linear vector extreme value problem is introduced in the partially ordered vector space. Some properties and results of the linear programming are generalized. And the existaence therom of basic optimal solution is proved.
1992, 14(4). DOI: 10.11835/j.issn.1674-4764.1992.04.013
Abstract:本文针对消防自动监控系统配线工程设计计算时确定∑_(QR),∑_(QC)和∑_(JR)等三组导线总数所存在的无据所依的问题,提出了设计计算它们的通用算式,并通过算例验证其实用性。因而为消防自动监控系统配线工程设计计算提供了理论依据。
1992, 14(4). DOI: 10.11835/j.issn.1674-4764.1992.04.015
Abstract:The volume of supply air of an underground water powerhouse is very large. Three methods of air distribution that do not occupy a lot of useful space, these methods are studied by scale model tests in this paper. The results of the tests show that the thermal environment quality at the far end away from the gate is poor if air is supplied from the gate. The velocity may be too high at some points in occupied zone if air is supplied from an end wall. This problem can be solved by reducing the supply air velocity or using an auxiliary slot. The effect of supplying air from the ceiling is satisfactory. The arrangement of one inlet under the ceiling for each generator's zone is recommended.
1992, 14(4). DOI: 10.11835/j.issn.1674-4764.1992.04.016
Abstract:本文得到了函数f∈L_q(R)在L_(p·q)(1≤p≤q<+∞)尺度下借助于Cardinal样条的最佳逼近的对偶定理。同时得出了用线性集作为逼近集的最佳L_(p·q)逼近元的特征定理。
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