OPTIMUM DESIGN OF ONE-STAGE DESENDING LIFELINE

The desending lifclinc is a new type of lifesaving device used in high buildings.Based on the principlc of opcration and structure,the mathematical model for the optimum design of one-stage desending lifeline is cstablished in this paper.A practical de-riga example is calculated with a mcthod of discrete variablc optimum design.Some prob-lems in design arc discussed briefly.     

THE PRACTICAL METHOD FOR STRUCTURAL FUZZY RELIABILITY ANALYSIS

Structural fuzzy reliability an alysis is to calculate the reliability of structureconsidering random and fuzzy of structural variables simultaneously.The method used needs multi-dimensional integration,the qtiantity of calculating is too large when there are more random vari-bles,so that not easy to use in practice. This paper presents the firstorder second -moment method andfour-moment method for structural fuzzy reliability analysis and provides favourable factors for ap-plication of fuzzy reliability methed.     

STUDY ON THE OPTIMUM DISTANCE BETWEEN CUTTING SLOTS FOR WEDGE PICKS

r The effect of the distance between cutting slots on the cutting specific energy consumption experimentally through cutting artificial coal samples with wedge picks is discussed in this paper. The optimum distances between cutting slots in different cut depths are presented, and the theoretical values are in good agreement with the experimental resurts.     

THE DECENTRALIZED LOAD FREGUENCY CONTROL FOR MULTI-AREA POWER SYSTEMS

A decoupled load-frequency control model of a multi-area interconnecting power system is presented and a practical and effective decentralized control method is developed, which needs only its own state information and the information measured in it. It can also improve the stability and dynamic characters of the system. The dynamic simulation of the numerical example of a three-area interconnecting system with this controller showes the dynamic characters are almost the same as the centralized full state feedback optimal control.     

A PRIMARY STUDY ON A LIFTING PERFORMANCE CURVE ADAPTED FOR THE MECHANICAL LOAD MOMENT LIMITER

The condition when forces are applied to load mechnical mornent limiter of tow-er cranes is analysed and disctissed in this paper.A lifting performance curve adapted for the me-chanical load moment limiter is also obtained.And finally,the curve drawing method is explainedthrough the practical example.     

PRACTICAL DESIGN OF PROBABILISTIC LIMIT STATES FOR STEEL STRUCTURES OF TALL BUILDING

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.     

粮仓应用铝箔空气层隔热冷负荷的计算

本文详细介绍了粮仓应用铝箔空气层隔热冷负荷的计算方法.为经济、合理地选择冷源设备提供了可靠的依据.     

AN EFFECTIVE DESIGN METHOD FOR PREVENTING COL LAPSE OF MULTI-STORY BUILDINGS TAKING ACCOUNT OF STRUCTURAL LOW-CYCLE FATIGUE CHARACTER

In this paper, through the theoretical analysis and a number of calclating, the statistic regression about the parameters in the failure criteria for aseismic structures presented by the authors are made. Based on this work, a simplified method for preventing collapse of multistory buildings taking account of structural low-cycle fatigue character is proposed.     

THE COMPUTER AIDED DESIGN SOFTWARE SYSTEM FOR THE STEEL STRUCTURE OF TOWER CRANE

This paper introduces the main structure and function,the theor-etical basis and the main features of the computer aided design software system QT-SCAD for the steel structure of tower crane.The QT-SCAD is suitable for allkinds of movable or fixable tower crane with level arm which rotates above thecrane body,and has single or double hanging points.It can be used for the stre-ngth,stiffness and stability analyses of the structure,the vibrative and dynamiccalculation of mechanisms and structure,and the optimal design of the structureof tower crane or its components.     

A SYSTEMATIC EVALUATION METHOD BUILDING DESIGN PLAN

This paper discusses the evaluation method of building design plan with the view of systematization and presents factors concerning building design plan. According to characteristics of multifactor, multipurpose, multifunction and multi-administrative levels in building design system, this comprehensive evaluation method provides a scientific basis for policymakers.     

A PRACTICAL METHOD FOR SELECTING STEEL USING COMPUTER AIDED DESIGN(CAD)SYSTEM FOR REINFORCED CONCRETE FRAME

How to select automatically the disposition of steel bar in a computer aided design(CAD)system for reinforced concrete frame structure is aproblem relatedt ot he practicality and increasing capacity of the CAD system.This paper suggests a practical method for selecting steel bar of beam in framestructure with the application of knowledge and experience of the experts forreasoning and judging.The method is convenient for calculation.The results ofcalculation are in agreement with detailing requirement and usual engineeringpractice.The method has great practical value.     

TO SOLVE PROBLEMS OF STRUCTURAL RELIABILITY BY MONTE CARLO METHOD

This paper uses simple and clear mathematical proving to expound the fundamental principle,usage and prospect of Monte Carlo method. This paper also gives an example which explains how Monte Carlo method is used for analysing structural reliabilty of engineering.     

THE STUDY OF DELAMINATION IN THE STRUCTURAL STEELS

The influence of temperature and stress state on delamination in the pipe-line steel has been studied by tensile tests at different temperature and stress states. It is found that the' delamination always takes place along the centerline segregation band in pipe-line steel produced by continuous casting and then controlled rolling. At room temperature, the delamination appears to be caused by micrbvoid nucleation and coalecence. And the delamination appears to be caused by the cleavage cracking along (100) plane at low temperatur.e. The best way to eliminate the delamination is to reduce the degree of centerline segregation.     

中国典型储粮生态区低温储粮的优化集成方案

根据储粮生态环境,将我国分为三个典型的低温储粮生态区域,即低温区、中温区和高温区。提出了三个储粮生态区域低温储粮对仓房隔热条件和气密条件的要求及不同地区低温储粮的优化集成方案。低温区最佳的低温储粮模式是:冬季通风降温 夏季隔热 适当控温;中温区最佳的低温储粮模式是:冬季机械通风降温 夏季严格隔热 必要的控温;高温区最佳的低温储粮模式为:冬季机械通风降温或谷物冷却机降温 夏季严格隔热 谷物冷却机降温。同时给出了三个储粮生态区域低温储粮优化方案的工艺流程图。     

A NEW METHOD FOR DESIGN OF PSS PARAMETERS

The eigenvalue sensitivity methods is very useful not only in analysis of electric power system stability but also in design of the controllers. In this paper a new optimal method is proposed to design the parameters of PSS. Using this method the PSS is designed for a single machine-infinite bus system, and the results of digital simulation show that this method is very effective and useful.     

FUZZY DISCERNMENT METHOD FOR WALL CLASSIFICATION IN AIR CONDITION LOAD CALCULATION

The building cold and hot loads calculation method for design-ers is spread and used in our country.There are total 301 kinds of commonwalls and roofs,which are classified as 6 types respectively.The cold loadtemperature tables are compiled for designers.With the development of build-ing science,there will be many new types of wall construction without classi-fication.This is inconvenient for fhis new calculation method to be spread.Inthis paper,a new method of wall classification is developed according to theprinciple of fuzzy colony discernment.We have got satisfactory result in com-parison with the result gained by load calculation method.This method invo-lves only algebra calculation and comparison calculation,such as taking bigger,taking smaller etc.,so it is simple and easy for designers to use.     

COMPUTER-AIDED ANALYSIS AND DESIGN FOR THE BASE STRUCTURE OF A MOVABLE TOWER CRANE

This paper is one of the achievements of the researchitem for computer-aided design of tower crane's steel structure.In thepaper,taking the well-base structure as an example,first the method establishing the mechanical model is explained for the base structure ofa movable tower crane.Then the math model of its optimal design andthe N-S figures for the computer program is described and calculatedusing discrete optimal technology.Finally the problems related to thedesign for the base structure of a movable tower crane are briefly illu-strated.