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.     

The Taylor series multipole boundary element method (TSM BEM)and its applications in rolling engineering

Rainfall is the main input for probabilistic analysis and prediction of rainfall-triggered landslide. The joint probabilistic structure of daily rainfall (DR) and cumulative rainfall (CR), which are dominant parameters of rainfall related on landslide in Chongqing region, was analyzed. Following the traditional technology, daily rainfall was translated into discrete variable by rainfall grade and cumulative rainfall became continuous variable if records with very small cumulative rainfall were ignored. Then joint probabilistic model of discrete variable and continuous one was derived, and transiting solution of conditional density function was put forward, together with its approximation via a family of Dirac δ sequences. Naturally, the proposed method was used to analyze conditional density function of cumulative rainfall in Chongqing region, and the numerical results were verified by comparison. However, most of the conditional density functions were irregular and not modeled by simple probability density function, thus the finite mixture distribution was introduced, which is of uncomplicated format and relatively high precision. At last, the joint probabilistic model of daily rainfall and cumulative rainfall was built up by combining frequency function of grade of daily rainfall with conditional density model of cumulative rainfall.     

Role of Nb in 14MnNbq Steel

In order to meet the needs of China-made gigantic bridges with long spans, 14MnNbq steel was developed . It is a new type of microalloyed steel. In this paper, simulated controlled rolling and cooling is taken. The role of microalloyed element Nb and Nb(CN) in the process of deformation and their effects on microstructures and mechanical properties of 14MnNbq steel are analysed by means of optical microscope, TEM, electrical chemical phase extraction analysis and micrography analysis.It is pointed out that in period of non-recrystallization of finish rolling should increase the deformation increment as great as possible to give full play to Nb, The cooling speed after rolling and the temperature of finish cooling should be controlled properly according to working condition to ensure Nb(CN) to separate out adequately. It is proved that Nb possesses good fine-grain strenghening and medium precipitate-hardening effects.     

THE ANALYSIS OF INFLUENCE OF RATE-SENSITIVE MATERIAL FOR PLATE ROLLING PROCESS BY THE RIGID-VISCOPLASTIC F.E.M.

The speed-up of the rolling production makes the effect of rate-sensitive material on the rolling process significant. In this paper the Rigid-viscoplastic F.E.M, has been used successfully to simulate the steady process of plate-rolling of rate-sensitive material. The experimental results of testing the rolling force is in good agreement with the result of computations. The emphasises put on the discussion of the effect of the rolling velocity on the rolling process.Some new results,which are difficult to obtained by other methods, are obtained. The analysis above express that the forward slip increases with increasing of rolling velocity.     

Study on Seismic Behavior of Edge Slab-column Connection

Under the action of lateral forces and vertical loads, the connection of reinforced concrete slab-column structure will not only transfer significant shear forces, but also unbalanced moment. As to the edge slab-column connection, even if there is no later force, it will also transfer unbalanced moment due to the asymmetry. Currently, most tests and studies focus on interior connections, but there are few tests or studies on edge slab-column connections. A relatively new type of shear reinforcement named shear-stud reinforcement was applied in edge column-slab connections and study on the seismic behavior of these connections was conducted. Tests and finite element analysis of three full-scale reinforced concrete edge slab-column connections subjected to gravity and unbalanced moment were completed in this paper, and main conclusions were as following: the bearing capacity, deformation capacity and seismic behavior of connections reinforced with shear-stud reinforcement are improved; deformation of specimens reinforced with shear-stud reinforcement could meet requirements of current codes; the performance of energy dissipating is as good as the common connections, and has reached the medium ductility level.     

Analysis of Elastic Deformation of Rollers System in Rolling Mill Based on Influential Function and Prediction of Plate Shape

Roll elastic deformation must be considered when plate rolling mill is designed and rebuilt and plate shape is controlled and improved. By using influential function method and computational formulas that are given, the roll deformation in some 1850 rolling mill is analyzed, and the results are used to predict the transverse thickness difference of plate. The results of prediction show that the method is correct.     

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.     

A STUDY OF THE DUPLEX YIELD CHARACTER OF DUAL PHASE STEEL

In this paper, the duplex yield character (DYC) of dualphase steel has been discussed. The results of the tests show that the DYC is due to the martensite deformation from the elastic state to the plastic state and the microvoid formed from the interphase boundaries. The DYC is directly affected by the phase ratio and the shape of structure. According to the different deformation character of the duplex phase, the uniform deformation of dual phase steel divide into three stages.     

Three Dimensional Eddy-current Field computation by Edge Finite Element Method of Mixed Elements

The edge finite element interpolation function of 1-forms for prism is derived.The electrical field intensity is used as the unknown variable.If the tangential component of electrical field intensity is an enforcing condition on the interface of eddy-current region and non-eddycurrent region,the tangential component of magnetic field intensity is a natural continuous condition.At last,the mixed elements of prism and hexahedron are used to compute a three dimensional eddy-current problem.     

THE CALCULATION OF DEFORMATION OF VARIABLE CROSS-SECTION COMPLEX LOAD-BEARING BEAMS

In this paper,the method of computing deformation ofuniform cross-section complex load bearing beam by using odd functionis introduced.By bringing forward a concept equivalent load,this methodcan be used to compute the deformation of variable cross-section complexload-bearing beams.It is of some practical value in calculation ofengineering structure.     

THE ANISOTROPY DISCONTINUITY MODEL DUO TO THE STRIKE OF THE TAGGED DISCONTINUITIES

In this paper, on the base of the original shapes of discontinuities in engineering gedogy, we mainly discuss the ralations among the shape of discontinuity, the restraining effects of discontinuity deformations (including the normal deformation and the shear deformation ) and the crustal stress. Then we put forword the concept of the pseudo-dilatancy ungle which can indicate the motion direction, set up the anisotropic discontinuity model, and give some important results and formula for illustrating truly the discontinuities in rock engineering.     

Flow Stress Behavior of 3104 Aluminum Alloy

According to different deformation conditions required in working process for manufacturing of 3104 aluminum alloy, the authors design the simulation experiments of hot rolling process at different deformation temperature and strain rates, analyze the relationships of deformation resistance, flow stress and strain rate, deformation temperature when alloy deformation. Based on experimental data analysis, it was concluded that the dominant factors affecting flow stress were the strain rate and deformation temperature, and the two parameters were also important for deforming process control.     

THE GENERAL FORMULAS OF SHAPE FUNCTIONS FOR THE HIGHER SERENDIPITY ISOPARAMETRIC ELEMENTS WITH VARIABLE NODES

In this paper,the united method for determining shape function is extended to higher Serendipity soparametric element with variable nodes,and the general formulas of shape functions for the element is obtained.The formu-las show great superiority for the Serendipity isoparametic transitional elements.     

THE ANALYSIS OF MECHANICAL CONSTRUCTION OF SURROUNDING ROCKS IN THE PITCHING SEAM

Defferent forms of mechanical construction, the distribution of stress, and the process of the deformation destruction in the enclosing rocks in a working face of a pitching seam are analyzed according to its geological and mining specialities.     

MODELLING DESIGN OF THE CAIYAN TUNNEL IN CHONGQING

A modelling design approach for the preliminary dimensioningof underground opening supports is presented in this paper. The method is basedon the model test results under the condition of plane deformation, It is tobe used for the analysis and design of the primary support measures and theproper thickness of secondar linings as welt as appropriate construelion tech-niques adapted to the condition of the Caiyuan Tunnel in Chongqing.     

Numerical Analysis of Thermo-Elastic Deformation for Cyindrical Gears

In this paper,both non-coupled numerical method of thermo-elastic deformation and coupled procedure for meshing gear are presented. The illustrative examples of gears applied in machine-tools and rolling mills show that this procedure is ralid and efficient.     

散装稻谷储藏品质变化规律的研究

对不同储存形式，不同储存部位的晚籼稻谷进样抽样检测，结果表明，无论是露天储存，还是仓内储存，粮堆边缘，中部各区域以及粮堆内的不同层次间，其储存品质均存在差异，而且有些部位的差异还十分明显，从抽样检测平均结果来看，储粮品质由好到差依次为：底层中层，上层，表层，稻谷储存品质的总特点是：底部储粮品质好于粮堆东，南，西，北各边缘储粮，其中以粮西部边缘的储粮品质最差，测定结果对今后合理处理陈粮，减少大批陈化粮损失及改善粮食储藏技术，均提供了科学依据。     

VARIATIONAL PRINCIPLE OF RATE PROBLEM OF ELASTICPLASTIC LARGE DEFORMATION AND IT''S APPLICATION

In this paper, based on Hill's general variational principle(l958-1959), a variational equation in intitial configuration ( reference configuration) and current configuration ( reference configuration ) is derived using convetced coordinates.The derived variational equation is for large elastoplastic, double nonlinear rate problem and is suited for finite element caculation.As an applied example of the derived variational equation, necking of a plane strain ploymer sheet with a initial geometric inperfection ( initial neck ) is analysed using the finite formulation based on the derived variational equation. Work hardening of materials is considered.The derived variational equation in this paper is suitable for analysing large elastoplastic deformation problem including metal forming processes.     

Analysis and Design of Stigmata Upsetting Die

Upsetting, a typical hot deformation process, is simulated by using rigid-viscoplastic finite-element method, its instantaneous stress distribution over the interface between the die and workpiece being derived for the finishing upsetting stage. Based on these computations and in conjunction with elastic finite element method,die strength is then analysized. An optimization design for prestressed die inserts is adopted to decrease pressure being applied to the working surface of upsetting die,and in turn,to prolong its service life.