鲤鱼钳毛坯楔横轧成形压力的工程计算

介绍了楔横轧成形过程的工艺参数及变形区参数,分析了楔横轧展宽区的金属变形情况及推导了变形区参数的工程计算公式。文末对鲤鱼钳毛坯进行了实例计算。     

三辊轧管机轧制的钢管表面裂纹缺陷分析

分析了三辊轧管机轧管过程中变形量和回转角等因素对钢管表面质量的影响 ,指出变形参数的不合理会对钢管表面有严重影响。     

螺旋叶片锥辊轧机的轧辊结构研究

通过分析辗轧变形区参数、优化组合轧机调整参数及轧辊结构参数,研究螺旋叶片辗轧机的轧辊结构,为开发设计新型螺旋叶片辗轧机提供了理论依据。并通过对辊缝分析,指明了这一工艺的发展方向。     

轴向进给辊轧热力耦合有限元模拟

利用商品化软件Deform3D对轴向进给辊轧变形过程 ,进行了三维有限元分析 ,得到了三维变形状态下轧件的温度场。网格重划技术和热力耦合的运用 ,更加精确地描述了整个变形过程。本研究对合理确定轴向进给辊轧工艺参数、提高产品质量具有重要意义     

螺旋叶片锥辊轧机的轧辊结构研究

通过分析轧轧变形区参数，优化组合轧机调整参数及轧结构参数，研究螺旋叶片辗 轧机的轧辊结构，     

冷轧管子的孔型轧槽宽度

冷轧管子的孔型轧槽宽度是孔型设计中的一个重要参数。它的选择是否恰当,直接影响管子的质量及轧机的产量。本文就轧槽开口度(轧槽宽度)的改变,所引起的不均匀变形程度的变化对轧管时的金属变形情况,力学条件及管子中的残余应力分布的影响进行了试验和分析。从改善管子质量及受力情况出发,提出了适当的孔型轧槽开口角及根据轧槽开口角计算轧槽宽度的公式。     

ШИРИНА РУЧЬЯ КАЛИБРА ПРИ ХОЛОДНОЙ ПРОКАТКЕ ТРУБ

冷轧管子的孔型轧槽宽度是孔型设计中的一个重要参数。它的选择是否恰当,直接影响管子的质量及轧机的产量。本文就轧槽开口度(轧槽宽度)的改变,所引起的不均匀变形程度的变化对轧管时的金属变形情况,力学条件及管子中的残余应力分布的影响进行了试验和分析。从改善管子质量及受力情况出发,提出了适当的孔型轧槽开口角及根据轧槽开口角计算轧槽宽度的公式。     

行星轧机的运动形式和轧管组织变化

文章结合三辊行星轧机的结构描述和工作原理，分析了轧制过程中轧管运动形式和轧制过程中轧管不旋转的条件。同时对变形区中的坯料的组织变化规律进行分析，阐明了各部分组织的变化。     

用能量法求解三辊轧管时轧制压力

根据三辊轧管机的轧制变形特点,在适当简化的前提下,建立了变形区运动许可速度场,推出了三辊轧管时平均单位压力计算公式,并得到实验验证。     

热轧双相钢变形和冷却工艺的研究

采用Gleeble-3800热模拟试验机研究了热轧DP双相钢的TMCP(Thermo Mechanical Control Process)工艺,分析工艺参数、变形量、冷却速度和缓冷时间对含Nb热轧双相钢显微组织性能的影响。研究发现:增大变形量和延长缓冷时间,铁素体含量增加,可获得细小铁素体组织;轧后冷却速度越大,马氏体总含量越多,铁素体晶粒尺寸越细小。大的终轧变形量和轧后适当延长缓冷时间是获得工业生产理想双相钢的工艺保证。     

无心磨削工艺参数的非线性优化研究

为了选择无心磨削的最佳工艺参数,通过对其加工原理及工艺参数进行分析,在满足产品技术要求和磨削加工条件等设计约束的前提下,建立磨削工艺参数优化的非线性数学模型。应用MATLAB优化工具箱对工艺参数进行优化计算,得到最佳的工艺参数。优化后的工艺参数使得单位时间内的金属切除率大幅度提高,优化计算的结果验证了此方法的有效性。     

Sensitivity analysis of submerged arc welding process parameters

Selection of process parameters has great influence on the quality of a welded connection. Mathematical modelling can be utilized in the optimization and control procedure of parameters. Rather than the well-known effects of main process parameters, this study focuses on the sensitivity analysis of parameters and fine tuning requirements of the parameters for optimum weld bead geometry. Changeable process parameters such as welding current, welding voltage and welding speed are used as design variables. The objective function is formed using width, height and penetration of the weld bead. Experimental part of the study is based on three level factorial design of three process parameters. In order to investigate the effects of input (process) parameters on output parameters, which determine the weld bead geometry, a mathematical model is constructed by using multiple curvilinear regression analysis. After carrying out a sensitivity analysis using developed empirical equations, relative effects of input parameters on output parameters are obtained. Effects of all three design parameters on the bead width and bead height show that even small changes in these parameters play an important role in the quality of welding operation. The results also reveal that the penetration is almost non-sensitive to the variations in voltage and speed.     

A three-dimensional model of clip flow, chip curl and chip breaking for oblique cutting

In recent years, many publications have appeared dealing with chip breaking in orthogonal cutting of metals. However, in industry, oblique cutting and not orthogonal cutting is encountered in almost all actual machining operations. This paper deals with a model of chip flow, chip curl and chip breaking for oblique cutting. To simplify the analysis, a set of equivalent parameters are introduced. The relationship between the machining parameters and their corresponding equivalent parameters is developed theoretically and experimentally. To assess the level of chip breaking, a criterion of chiplbreaking is suggested under the concept of these equivalent parameters. The agreement of the experimental results with the predictive data of the model verifies that the definition of these equivalent parameters is reasonable. The influences of various machining parameters are discussed, in relation to their corresponding parameters. One significant finding is that the effect of each of the machining parameters on chip breaking is not totally inpdependent of one another. This implies that careful attention must be paid to the relationship between various machining parameters in three-dimensional parameters.     

Artificial Neural Networks vs. Fuzzy Logic: Simple Tools to Predict and Control Complex Processes—Application to Plasma Spray Processes

The plasma-sprayed coating architecture and in-service properties are derived from an amalgamation of intrinsic and extrinsic spray parameters. These parameters are interrelated; following mostly non-linear relationships. For example, adjusting power parameters (to modify particle temperature and velocity upon impact) also implies an adjustment of the feedstock injection parameters in order to optimize geometric and kinematic parameters. Optimization of the operating parameters is a first step. Controlling these is a second step and consists of defining unique combinations of parameter sets and maintaining them as constant during the entire spray process. These unique combinations must be defined with regard to the in-service coating properties. Several groups of operating parameters control the plasma spray process; namely (i) extrinsic parameters that can be adjusted directly (e.g., the arc current intensity) and (ii) intrinsic parameters, such as the particle velocity or its temperature upon impact, that are indirectly adjusted. Artificial intelligence (AI) is a suitable approach to predict operating parameters to attain required coating characteristics. Artificial Neural Networks (ANN) and Fuzzy Logic (FL) were implemented to predict in-flight particles characteristics as a function of power process parameters. The so-predicted operating parameters resulting from both methods were compared. The spray parameters are also predicted as a function of achieving a specified hardness or a required porosity level. The predicted operating parameters were compared with the predicted in-flight particle characteristics. The specific case of the deposition of alumina-titania (Al₂O₃-TiO₂, 13% by weight) by APS is considered.     

锯切参数与花岗岩适应性研究

依据实验和实践结果,系统研究了最佳锯切参数(包括锯切工艺参数和锯片性能参数)与花岗岩物理力学性能之间的相关关系,提出了合理选择锯切参数的一般原则。     

The influence of combined laser parameters on in-situ formed TiC morphology during laser cladding

In this paper, the effect of laser cladding process parameters on TiC morphology is studied. Results show that laser parameters play a crucial role in morphology of TiC. Dendritic or spherical TiC particles with different distribution are observed depending on applied laser parameters. Two combined parameters, effective energy and powder deposition density, are used in order to study the effect of laser process parameters on TiC morphology.A series of experiments are conducted in constant laser power and scan speed, constant effective energy and constant powder deposition density in order to study the TiC morphologies. Results show that both combined parameters and laser parameters should be considered in order to interpret the results. Laser parameters have crucial role in establishing the TiC morphologies by means of temperature and chemical composition.Hardness results of the clad zone depend on morphologies and distributions of TiC particles in the clad.     

无损检测中常用声发射参数的分析与评价

以自己和其他研究者的实验结果为基础,根据声发射参数本身的内涵和对声发射过程描述的方式和角度,将声发射参数分为基本参数和特征参数、过程参数和状态参数,并对不同参数对材料声发射性能的描述特点、灵敏度及适用条件进行了概括和分析。     

基于证据理论的岩体力学参数信度估计方法

针对岩体力学参数的未确知性 ,提出了基于证据理论的岩体力学参数信度估计方法。在构造岩体力学参数的识别框架上 ,对多个具有不同信度的抽样试验证据用Dempster Shafer合成法则进行信度综合 ,从而获得在其识别框架上的基本可信度分配、信任函数和似真函数 ,并在此基础上 ,利用定义的类概率函数确定岩体力学参数的取值。应用实例表明 ,该方法在岩体力学参数的分析和选取上取得了较好的结果。     

柔性机座-转子系统动力学参数优化仿真

以M701F重型燃气轮机转子系统作为研究对象,建立柔性机座-转子系统动力学模型;计入柔性机座-转子系统动力学参数全局性变化范围,提出全局匹配分析方法并实现了动力学参数全局最佳匹配数值计算软件系统;通过跟踪研究计入全局动力学参数下机座动力参数最佳匹配点和轨迹的变化规律,揭示不同转子动力学参数下机座参数最佳匹配点轨迹特征,...     

附加参数与基本参数空间关系的度量

合理地选择参数,避免参数间的强复共线性,是参数有效估计的关键之一。通过将参数Ｘ分为两类,即基本参数Ｘ１和附加参数Ｘ２。并假定附加参数的选取不当是造成参数间强复共线性的主要原因,提出了用点（Ｘ２中的一列向量）到空间（由Ｘ１所对应的列向量张成Ｈｉｌｂｅｒｔ空间的子空间Ｈ０）夹角的正弦值作为度量标准来优选附加参数,给出了该方法的理论论证,并用两个算便对度量方法进行了验证和说明。