THE STUDY OF STRAIN FATIGUE CRACK PROPAGATION BEHAVOURS OF VANADIUM BEARING HSLA STEEL

In this paper, the strain fatigue: crack propagation rates of vanadium bearing HSLA steel with different micro-structures are measured under constant load conditions, and the relationship between the crack propagation rate and the microstructures of steel is also studied.     

A SIMPLIFIED PLASTIC ZONE METHOD FORSECON DORDER ELASTICPLASTIC ANALYSISOF STEEL FRAMES

This paper presents a simplified plastic zone method with consideration of the in-fluences of the PDelta. residual stress ,degradation of crosssectional stiffness and plastic zone lengthon the stiffness matrix for second-order elastic-plastic analysis of steel frames. The method not onlymakes up for a insufficiency which is that the degradation of crosssectional stiffness and plasticzone length in a member ean not be considered by a plastic hinge method but also overcomes a defectwhich is very costly and time-consuming because a fine mesh discretization across the crosssectionand along the member length is required by a plastic zone methed. Analysis result Shows proposedsimplified rnethod is simple and practical.     

THE METHOD AND ITS APPLICATION FOR COUPLED ANALYSING PLASTIC DEFORMATION OF ROLLING WORKPIECE AND ELASTIC DEFORMATION OF ROLLS

A method for coupled analysing plastic deformation of rolling workpiece and elastic de'formaticn of rolls is developed. The interaction of plastic defo rmation of rolling workpice and elastic deformation of rolls is considered. The couple is formulated by setting up force equilibrium equation at the interface of the rolling workpiece and tne rolls. The plastic deformation of rolling workpiece is treated by the rigid plastic finite element method and the elastic deformation of rolls is treated by the boundary element method. The rolling presure, perunit. forward slip, neutral from angle obtained from coupled analysis are lower than those obta-ined rigid rolls. The results obtained from analysis show that the analytical accuracy can be heightened using the coupled ana-ytical methcd dveeloped for treatng rolling3proccss.     

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.     

THE METHOD OF THE MEASUREMENT OF THE WORMWHEEL PROFILE ERROR WITH THE THREE-COORDINATE-MEASURE-MACHINE

In this paper we explain the method of the measurement of the wormwheel profile error with the three coordinate measuring machine. We first establish the wormwheel theoritical tooth profile equation according to the gear engage principle, then write the computing program and calculate the wormwheel theoritical profile, next analyse and calculate the error of the gage head interference. At last, we work out the measuring program and get the wormwheel profile measured with the three-coordinate measuring machine.     

MEASUREMENT OF THE DISTRIBUTION OF HUMAN FOOTSOLE PRESSURE WITH SHADOW MOIRE METHOD

The distribution of human footsole pressure are measured with the shadow moire method and the force-displacement transducer array is designed,the latter of which is in the form of extension springs,one in every 0. 49cm2. Because hundreds of transducers are arranged in the area of the footsole,the pressure distribution of the human footsole could be exactly responded.     

DETERMING THE RELIABILITY OF A MEMBER WITH CRACK ACCORDING TO THE INFORMATION FROM FLAW-DETECTION WITH ULTRASONIC WAVE

Using the flaw-detecting with ultrasonic wave one may know the equivalant area of a crack that burys in the member. If the crack is ellipse shaped, the equivalant area is constant, and the distribution function of its major semiaxle and the plane strain fracture toughness of the material are given, then we would get the probability of reliability of the member under the uniform tension. In this condition, a formula of calculating the probability would be provided in this paper. Because a simple and enough precise approximate function has been introduced the formula in the paper is simple in shape and easy to use.     

AN ENTHALPY METHOD OF SOLVING PHASE CHANGE PROBLEMS BY COUPLING THE ENTHALPY AND THE MOVING BOUNDARY

A numerical enthalpy method is proposed for solving the multi-dimensional phase change problem by coupling the enthalpy and the moving boundary. Its basic feature is to sepasate appearent and latent heat terms by transforming the standard enthalpy relation and to couple them into the latent heat term by introducing the idea of phase change rate between the axes and simultaneously to correct the heat flux of the inflowing/outflowing phase change control volume element , so that the accuracy of numerical solution is improved and the moving boundary can be accurately followed.     

THE APPLICATION OF MULTIBODY DISCRETE METHOD IN RING''S VIBRATION ANALYSIS

A ring's muJtibody discrete model is discussed in this paper. The ring's plane geometric nonlinear vibration equations are derived. Compared with the finite element and lump mass methods, this method is better. In the last pa it of the paper, the eigenvalues, the first 9 modes of the ring, the geometric nonlinear dynamic responses of the ring are calculated.     

THE ARC-LENGTH METHOD OF SECANT RIGIDITY IN FRAME ANALYSIS

The secant rigidity is used for the are-length method to solve the nonlinear finite elements problems. The advantage of this method is unnecessary of calculating the initial resistance term caused by the incremental step. The computational work is less and the programing is easier as compared with initial are-length method. This method can be widely used to solve nonlinear problems.     

OPTIMAL SELECTION ON THE INTERVALS FOR HANDLIND THE RHYSICAL EXPERIMENT DATA BY THE METHOD OF DIFFERENCE WITH DATUM BY DATUM

This paper discusses the mechanism and reason for decreasing the handling polynomial function data on difference with durum by datum.From the error theory,some exemples are analysed and the equivalent principle for the intervals on datum by datum is presented.The optimal number for intervals is analysed in detail and shown by some examples for the correct result.At last,by making comparison between some methods for handling the physical experimental data to show the advantages of them,the proper condition and range in use for every method is also presented.     

THE METHOD OF FORMING HOURLY OUTDOOR TEMPERATURE BY SPLINE FUNCTIONS AND ANAYSIS OF ERRORS

It is necessary to input the hourly meteorological data in order to analyze building annual energy consumption and to simulate dynamically air-conditioning systems.The hourly outdoor temperature constituted by cubic splineinterpolation when forming meteorological data is used for building energy anal-ysis.This paper analyzes the theory of spline function interpolation errors affe-cted by boundary conditions and introduces the methods to decrease interpolationerror.     

A NEW METHOD OF RESEARCHINE THE SITE DUPLE FACE DYNAMIC BALANCE OF MACHINE RIGID ROTATOR BASE DON AMPLITUDE MEASUREMENT

In this paper, a new method of researching; the site dupleface dynamic balance of machine rigid rotator, namely duple test weightmethod is presented. Weight the new method against the existing method,namely single test weight method [1], both the efficiency increasing and theenergy-consumming dicreasing would be forty percent and over, with thebasic points of vibration theory, the formula of calculating weight andposition of the duple face dynamic unbalance of a rotator by means ofapplying the duple test weight is developed in detail. The method in handll-ing distinct bearing form is also discussed. Rightness of the new method isproved out by the living example of the simulant contrast testing carried outn the dynamic balance test machine and the site balance for a rotatorsystem of motor.     

毛细管气相色谱内标法测定防霉剂中富马酸二甲酯

建立了巴豆酸为内标物,用毛细管气相色谱快速测定防霉剂中富马酸二甲酯含量的方法.样品用乙酸乙酯提取,以DM-FFAP毛细管柱分离,火焰离子化检测器检测.结果表明,在0.25～3.0 mg/mL浓度范围内,富马酸二甲酯和巴豆酸的浓度比与峰面积比的回归方程为y=-0.0009 0.7174x,相关系数r=0.9996,检出限为5.0 mg/L;样品加标回收率(n=6)为97.0%～104.0%,相对标准偏差为3.26%.该方法简单、快速、准确度好,可用于测定防霉剂中的富马酸二甲酯含量.     

A BOUNDARY ELEMENT METHOD FOR THE NEUMANN PROBLEM OF HELMHOLTZ EQUATION BY USE OF A DOUBLE LAYER POTENTIAL IN R~3

This paper presents a new numerical solution for Neumann problem of Helmholtz equation in R~3. The expression of the solution for this problem is obtained by use of a double layer potential and it leads to a Fredholm boundary integral equation of the first kind. Then, the existence and unicity of the integral equation which is equivalent to the boundary value problem are obtained in a suitable Sobolev space. Finally, a variational form which is equivalent to the integral equation is applied to the construction of a finite element method and the error estimate is given.