INVESTIGATION ABOUT DETERMINATION OF COLUMN EFFECTIVE LENGTH OF STEEL FRAMES WITH FLEXIBLE JOINTS

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.     

THE STUDY OF ANTI-SEISMIC BEHAVIOR OF THE TOP CORNER JOINTS OF REINFORCED CONCRETE FRAME WITH THE INCLUSION OF STEEL FIBRES

This paper first discusses the limited effect of steel fibre reinforcement on plain concrete and reinforced concrete. Then, making a comparison among the test results of three full-scale top corner joint assemblies of frame, in which only two of them are added with steel fibres in joint zone. The advantageous and disadvantageous influence in anti-seismic aspect is investigated after adding steel fibres in the joint zone. Finally, this paper gives an overall comment on the application future of using the steel fibres in every kinds of joint of anti-seismic reinforced concrete frame.     

BEHAVIOR OF THE REINFORCED CONCRETE FRAME CORNER JOINTS SUBJECTED TO CLOSING LOADS

In this paper, experimental results on the tests of 15 full-scale reinforces concrete frame corner joints subjected to closing loads arereported. The primary variables are the compressive strength of eoncrete, thesteel ratio and the ratius of main bar bend. In order to investigate the stressdistributiens of the concrete in the cores of the joints, a nonlinear finiteelement analysis of the frame corner jonts is carried out. Possible damage andfailure modes of the frame corner joints are discussed herein. Based on observedand computed results, the formulae in terms of the steel ratio and the ratius ofmain bar bend and the corresponding useful recommendations are made for thedesign of the frame corner joints.     

PROBABILISTIC EVALUATION FOR STEEL FRAME COLUMNS OF TALL BUILDINGS

Based on properties of parameters and test data of dom-estic steel,this paper analyses the reliability and partial coefficient forresistance of steel frame columns of tall builings.The result may serveas a scientific basis.It is not only for domestic steel instead of importedsteel in building tall steel structures,but also for compiling concerendstandards.     

TENTATIVE INVESTIGATION OF THE BEHAVIOR OF REINFORCED CONCRETE FRAME CORNER JOINTS UNDER LOW CYCLE LOADING

In this pager, four full-scale corner joint assemblies of reinforced concrete frame beam and column with different detail structure are tested under low cycle loading, The process of damage development and the characteristics of break of the assemblies in the course of alternately increasing positive and negative bending deformation are learned Strength, stiffness and ductility of assemblies and the various regulations of energy consumption are also studied. Compared with these properties, the anti-seismic behavior is tentatively commented. Besides, the test results of the strain distribution of beam and column longitudinal bars and stress state of joint stirrups are analyzed.     

AN EXPERIMENTAL STUDY ON THE ANTISEISMIC BEHAVIOR OF THE BRICK BUILDING WITH FRAME ON THE GROUND FLOOR

A two-story and two-space structure model (1/4 scale) is tested under low-cyclic loading for studying the antiseismic behavior of the brick building with frame on the ground floor. This paper presents mainly the development and pattern of cracks, failure mechanism,hysteresis behavior, strength and stiffness, ductility and energy dissipation. The calculated results by elastic finite elemet method are also compared with the results of test.     

THE EFFECTS OF RESTRAINT STRESS ON PHASE TRANSFORMATION AND FRACTURE TOUGHNESS IN WELD HAZ OF 15MnMoVNRE STEEL

The effects of restraint stress on phase transformation and fracture toughness COD in weld HAZ of 15MnMoVNRE steel were studied by means of weld thermal simulation and COD testing. The results show that restraint stress accelerates phase transformation and makes the fracture toughness COD higher.     

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.     

EFFECT OF HIGH LOADS IN THE BRIDGE LOAD SPECTRUM ON FATIGUE CRACK GROWTH OF 16 Mn STEEL

This paper studies an effect of high loads in Rayleigh distribution random load-ing on fatigue crack growth wi th 16 Mn steel compact tenion specimen,The results show that thehigh loads in the load spectrum close to service load of steel bridges accelerate crack growth and re-duce crack growth life,Lives predicted with constant amplitude da/dn data and equivalent loads arequite in agreement with test lives.     

EXPERIMENTAL STUDY ON STATIC ANCHORAGE BEHAVIOR OF BEAM BARS WITN 90-DEGREE HOOK IN EXTERIOR JOINTS OF R/C FRAMES

In order to investigate the influence of concrete strength,horlzontal and verticalportions of anchorage length and cover thickness etc,upon the mechanical performance of 90-degreehooks of beam upper bars in exterior joints,static experiments of 40 beam- column subassemblagesare carried out. This study emphasizes the damage characteristics of the anchorage zone,measures thestrains of the bars along the anchorage length and analyzes the special anchorage mechanism of suchhooks of beam bars.     

FREQUENCY CALCULATION OF SPACE FRAME STRUCTURE BY A WAVEFRONT AND AN ITERATED POWER METHOD

In this paper,the frequency of space frame structure is obtained by a wavefront and an iterated power method.The computer internal storage is greatly saved.The solution so obtalned is quite in agreement with the finite solution.     

间断热辐射对钢板仓中稻谷温度和水分影响的模拟研究

运用远红外电热幕对装有0.8m3稻谷的钢板仓进行热辐射,研究太阳辐射对钢板仓中粮温传递的影响。稻谷初始湿基水分含量为14.75%±0.35%,辐射时控制模拟仓辐射面温度分别为30℃、45℃和60℃,每个条件试验周期为6d,辐射时间为8:00到20:00。结果表明,距辐射面相同粮层温度上升速率随辐射温度上升而增大;相同辐射条件下升温速率随粮层厚度增大而下降。距辐射面5cm和15cm粮层受环境温度影响,粮温白天上升夜间下降;25cm、35cm和55cm粮层在整个试验过程中粮温持续缓慢上升;75cm粮层从第36h开始温度缓慢上升,相同辐射条件下不同粮层升温速率差异性显著(p0.05)。拟合得到时间(T)和粮层厚度(S)的二元二次粮温上升速率方程:V=a-bT-cS+dT2+f(T-72)(S-0.35)-g(S-0.35)(T2-6336),a、b、c、d、f、g为常数,R2≥0.832,该方程可预测不同时间、不同粮层厚度的升温速率。     

大豆主要品质指标对其力学特性的影响

为研究大豆主要品质指标与大豆机械力学特性的关系,探讨用于评价大豆机械性能的理化特性指标。以5种大豆为原料,分析了不同大豆品种的水分含量、籽粒大小、化学品质与大豆长轴、短轴挤压力学特性的相关性。结果表明:随着含水率的增加,大豆籽粒的破裂力均逐渐减小,压缩功则逐渐增大;长轴和短轴的挤压力学特性参数不同,短轴压缩时大豆的总体力学特性参数更大;籽粒的尺寸、形状与大豆的挤压力学特性关系密切,籽粒大小与大豆的挤压力学特性呈正相关;粗蛋白含量与大豆挤压力学特性呈正相关,粗脂肪含量与大豆挤压力学特性呈负相关。研究结果可为大豆储运、加工设备设计的优化以及大豆的品质评价提供一定的参考。     

RATIONAL DETERMINATION OF TNE BEAM AND COLUMN CROSS-SECTIONAL SIZES OF THE FRAME STRUCTURE IN A EARTHQUAKE ZONE

At the preliminary design stage of a building, it is neccssary to determine thebeam and column cross-sectional sizes of frame strtictures.According to some provisions of the"Building Aseismatic Design Code"(GBJ 11-89),main factors having influence on the beam andcolumn cross-sectional sizes are analyzed.and calculating formulas for the determination of the beam and column cross-sectional sizes which are satisfied the restrained condition of horizontal dis-placement of a building are derived in this paper.     

EXPERIMENTED INVESTIGATION OF EFFECT OF THE INCLINATION ON HEAT TRANSFER ON TUBE

The present paper discribes experiment research of effect of the inclination on heat transfer on 9 kinds of plain tubes in atomosphere, working fluids are distill water and ethanel. Experinent result show very obvious effect of inclination of pool boiling heat transfer. The larger heat transfer increases, the larger the inclination does. The correlation obtained on 524 experiment data can be used for reference to engineering design in prospect of heat transger coefficient.     

不同破损粒含量玉米陈化试验

将破碎粒分别为0%、4%、8%和12%的四组样品同时置于恒温恒湿的培养箱内进行陈化试验。分别于试验开始后的第0天、第7天、第15天、第22天、第30天、第49天、第59天取出实验样品采用GB/T 20570-2006方法检测各组玉米的脂肪酸值。结果表明：随着玉米破损粒含量的增加,玉米脂肪酸值随储藏时间的变化速度加快,即玉米破损粒含量与玉米脂肪酸值递增的速率呈正相关。     

THE INFLUENCE OF MANGANESE ON STRAIN-AGING BEHAVIORS OF REINFORCING STEEL BARS

The influence of different manganese contents on strain-aging behaviors of C-Mn-Si reinforcing steel bars are investigated. With the increase of manganese, the sensibility of strain-aging is decreased to somg extent. The experimental methods of strain-aging are also dicussed.