共查询到20条相似文献,搜索用时 31 毫秒
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An FE model was developed to study thermal behavior during the rod and wire hot continuous rolling process. The FE code MSCMarc was used in the simulation using implicit static arithmetic. The whole rolling process of 30 passes was separated and simulated with several continuous 3D elastic plastic FE models. A rigid pushing body and a data transfer technique were introduced into this model. The on line experiments were conducted on 304 stainless steel and GCr15 steel hot continuous rolling process to prove the results of simulation by implicit static FEM. The results show that the temperature results of finite element simulations are in good agreement with experiments, which indicate that the FE model developed in this study is effective and efficient. 相似文献
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Experiments on Laser butt welding of 904L super austenitic stainless steel was conducted using diffusion cooled 3.5 kW slab CO2 laser welding system. The weld geometries such as bead width and depth of penetration were measured. The laser welding process has also been simulated using ANSYS a Finite Element Analysis tool. The effect of laser power, welding speed and focal point position on the bead geometry was investigated. The experimental plan was developed based on the Taguchi technique. The comparison of the results of the simulation indicates that Finite Element Method (FEM) can predict the responses adequately within the limits of welding parameters being used. It is suggested that FEM can be used as a tool for predicting the bead geometry at low values of heat input on laser welding. 相似文献
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Mróz Sebastian 《钢铁研究学报(英文版)》2012,19(8):17-24
Change in the temperature of band over its length, associated with the stock being non-uniformly heated in the furnace, influences the variations in the magnitudes of energy-force parameters. Using the FEM (Finite Element Model) programs for the computation of the values of the energy-force parameters can take into account the distribution of temperature over the band length. The mathematical model of the computer program Forge2008 was used to theoretically examine the energy-force parameters and plastic metal flow in the roughing stands of the continuous rolling mill. The results of experimental investigation of influence of the non-uniform temperature distribution were presented on the metallic charge length on the energy and force parameters and dimensions of the band during round bars rolling. Thermovision monitoring energy and force parameters monitoring were carried out in continuous rolling mill D350 in one of the Polish industrial plants. On the basis of obtained results, it could be stated that non-uniform distribution of temperatures along the charge length causes local increase of energy and force parameters values and also such distribution affects the local increase of the width of rolled band. The rolling process of charge with non-uniform distribution of temperature could lead to exceeding required dimensional tolerances of the final products. 相似文献
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An experience is presented using the finite element method (FEM) and data mining (DM) techniques to develop models that can be used to optimize the skin-pass rolling process based on its operating conditions. A FE model based on a real skin-pass process is built and validated. Based on this model, a group of FE models is simulated with different adjustment parameters and with different materials for the sheet; both variables are chosen from pre-set ranges. From all FE model simulations, a database is generated; this database is made up of the above mentioned adjustment parameters, sheet properties and the variables of the process arising from the simulation of the model. Various types of data mining algorithms are used to develop predictive models for each of the variables of the process. The best predictive models can be used to predict experimentally hard-to-measure variables (internal stresses, internal strains, etc) which are useful in the optimal design of the process or to be applied in real time control systems of a skin-pass process in-plant. 相似文献
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短行程控制是热轧粗轧调宽过程中改善带钢端部形状、减少成材率损失的主要方法,而宝钢某热轧机组采用的传统的折线式短行程控制效果较差。采用刚塑性有限元法建立了立轧/平轧三维热应力耦合有限元模型,对粗轧机组轧制过程进行了全过程模拟,模拟结果得到实物验证。根据有限元模拟得到的带钢头尾失宽曲线,运用多项式插值原理,建立了短行程多项式模型,实际使用后提高了轧线成材率。 相似文献
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This paper presents a possibility of creating a virtual process chain consisting of forming and welding. Independent of any manufacturing process, a variable Finite Element model is introduced. This model can be an input for more than one simulation by means of the Finite Element Method (FEM). The process chain forming and welding is chosen to demonstrate the need and the importance to simulate a process chain in comparison to a single process simulation. Each simulation has its own specifications and intentions. Therefore, an FE‐model for a forming simulation is different from a model for a welding simulation. In this paper a way is shown how to keep the model and the results of a forming simulation for the succeeding simulation of welding. The results of the forming simulation remain as an initial state in the welding simulation. Thereby, a spring‐back behaviour can be modelled. A few adjustments have to be done to satisfy the specifications of the welding simulation. The used material for the integrated simulation is a DC 04 steel. Therefore, metallurgical phases must be considered to achieve sufficient results. For reasons of further industrial applications commercial FE‐solvers are used for calculations. The method of integration is applied to different examples. The verified results are presented and discussed. The simulated transient distortional behaviour of a formed and welded part is presented and compared to a mere welding simulation. A significant improvement of the distortion as a result of the welding simulation is reached by consideration of a previous forming simulation. 相似文献
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Gert Pettersson 《国际钢铁研究》2006,77(12):866-872
In this paper root cracks in a welded structure are investigated using the effective notch stress approach and Linear Elastic Fracture Mechanics (LEFM). The problem is complicated by the fact that the welds subjected to endurance stress are located close to a screw joint. The Finite Element (FE) model used for evaluating the fatigue life includes both this screw joint as well as adjacent components and the contact behaviour between the structures. Several important problems in the evaluation of stress intensity factors and notch stresses are investigated. The results can give useful information in the work of performing a fatigue analysis. The areas examined are the significance of the load direction, mesh density, the importance of the right global stiffness in the model, the crack deflection angle and the modelling of a root notch versus the requirements on the drawing. 相似文献
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LIJian-chao CUIJian-zhong MAYong-lin WANGBao-feng 《钢铁研究学报(英文版)》2004,11(2):30-33
A study on prediction of deformation behavior (rolling force, equilibrium strain,spread) during rolling was accomplished with FE code ANSYS/LS-DYNA. The laboratory experiments were conducted on a two-high mill with roll diameter of 170 mm to approve the results of simulation by explicit dynamics FEM. It was found that there is a good agreement between calculated and experimental data, which means that the shape rolling could be analyzed by means of explicit dynamics FEM. 相似文献
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板厚对冷弯成型过程及回弹影响的有限元模拟 总被引:1,自引:0,他引:1
采用ANSYS/LS-DYNA有限元软件的显式求解功能对厚度分别为4mm、5mm、6mm、7mm、8mm的板料进行有限元弹塑性分析,得到板料成型过程中厚度因素对轧件应力、应变的影响规律。接着利用ANSYS的隐式求解功能分析厚度因素对板料回弹的影响规律,并将回弹量的模拟数值与工作现场的回弹数值进行比较,表明计算结果具有一定的可信度。 相似文献
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Dmitry Orlov Arnaud Pougis Rimma Lapovok Laszlo S. Toth Ilana B. Timokhina Peter D. Hodgson Arunansu Haldar Debashish Bhattacharjee 《Metallurgical and Materials Transactions A》2013,44(9):4346-4359
IF steel sheets were processed by conventional symmetric and asymmetric rolling (ASR) at ambient temperature. The asymmetry was introduced in a geometric way using differential roll diameters with a number of different ratios. The material strength was measured by tensile testing and the microstructure was analyzed by optical and transmission electron microscopy as well as electron backscatter diffraction (EBSD) analysis. Texture was also successfully measured by EBSD using large surface areas. Finite element (FE) simulations were carried out for multiple passes to obtain the strain distribution after rolling. From the FE results, the velocity gradient along selected flow lines was extracted and the evolution of the texture was simulated using polycrystal plasticity modeling. The best mechanical properties were obtained after ASR using a roll diameter ratio of 2. The textures appeared to be tilted up to 12 deg around the transverse direction, which were simulated with the FE-combined polycrystal plasticity modeling in good agreement with measurements. The simulation work revealed that the shear component introduced by ASR was about the same magnitude as the normal component of the rolling strain tensor. 相似文献
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Thermomechanical Controlled Processing (TMCP) including accelerated cooling after the final hot rolling pass is a well-established technology,widely applied in HSLA steel plate production.However,there are still certain limitations,especially for thicker plate.The rolling schedule includes a long holding period (HP) after the roughing stage to allow the temperature to fall sufficiently for optimised TMCP during finishing.Intermediate Forced Cooling (IFC) applied during the HP can increase productivity by decreasing the required hold time,can restrict austenite grain growth,and can also improve the subsequent strain penetration in thick plate with further metallurgical benefits.Multi-pass plane strain compression (PSC) tests have been performed on the thermomechanical compression (TMC) machine at Sheffield University including different severities of IFC.Clearly it is impossible to simulate all aspects of the temperature and strain gradients present in thick plates in laboratory specimens,and most of the tests were conducted at temperatures and strains calculated by Finite Element modelling as relevant to specific positions through the plate thickness.However,some aspects of the gradients were addressed with tests using cold platens.The results have indeed shown that IFC can shorten the HP and reduce austenite grain growth and its variation across thick plate. 相似文献
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Properties of deformed steels depend on various microstructure parameters such as distribution of grain size and precipitates. Strain, strain rate and temperature inhomogeneities make quantitative prediction of microstructure difficult but the Finite Element method is able to model these inhomogeneities. Different scales of phenomena occurring in deformed materials are another difficulty in modelling. Microstructure evolution can be described by more realistic methods (e.g. Cellular Automata CA, Monte Carlo), which, on the other hand, are unable to simulate larger samples. Therefore, development of the methods capable of spanning multiple scales became a current challenge. CAFE modelling, which couples FE and CA methods, is the objective of the paper. The model consists of two layers. The micro‐scale layer, simulated by CA, represents microstructure evolution including nucleation and growth of the grains. Evolution of a dislocation density is described for every grain separately by solving differential equation. The FE thermal‐mechanical model is used as a macro‐scale part. Multistage plane strain compression tests for niobium steel are considered. Distributions of initial and final grain size are measured during the tests. The results from the CAFE model are compared to the measurements and to the predictions by a conventional model. The comparisons confirm the capability of the CAFE method to predict flow stress, recrystallized fraction and grain size distribution. Conventional approach gives a good agreement with experiments for an average grain size only. 相似文献
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轧制过程奇异点的存在使得求解不易收敛,是有限元求解轧制过程问题的难点之一。提出了采用双速度点模型解决第一类奇异点问题和相对滑动速度抛物线模型解决第二类奇异点问题。以某钢厂实际轧制数据为例,分析比较了奇异点处理方法对速度场以及计算时间和迭代次数的影响。当单元数从200增加到2 000时,采用双速度点模型处理第一类奇异点问题时计算时间和迭代收敛步数减少8%~67%,采用相对滑动速度抛物线模型处理第二类奇异点问题时计算时间和迭代步数减少15%~61%。双速度模型和抛物线模型处理奇异点方法加快了计算速度并改善了求解的收敛性。 相似文献
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Sabita Ghosh Mita Tarafder S. Sivaprasad Soumitra Tarafder 《Transactions of the Indian Institute of Metals》2010,63(2-3):617-622
Determination of mechanical properties of materials using non-conventional techniques has been an active area of research for a long time. Among various small specimen techniques to determine mechanical properties of materials, the ball indentation technique (BIT) has proved to be advantageous. BIT is used to measure material’s mechanical properties including fracture toughness when a tensile test cannot be performed: on welded joints or critical locations of components under service. The present work highlights the applicability of BIT for evaluating flow behaviour of engineering structural steels En24. Standard mechanical properties like ultimate tensile strength, yield stress, strain hardening coefficient evaluated for steels with varying microstructures generated through heat treatment. To determine fracture toughness from the flow behaviour, non linear damage models have been utilized. Using this model, fracture toughness of the En24 steel at different heat treated conditions has been computed using the results generated by the BIT. These results are verified with the already established correlation in literature. Numerical validation of the results generated by the BIT has been carried out by Finite Element Modelling (FEM) using standard ABAQUS software package. The FE model of the BI simulation helps to compute sub indenter stress-strain fields which determine the extent of pile-up in highly ductile materials. 相似文献