Characterization of angular dependence of macroscopic magnetic properties in ASTM 36 steel using magnetic Barkhausen noise

Angular-dependent magnetic Barkhausen noise measurements were performed on ASTM 36 steel samples for various values of applied uniaxial stress. The maximum differential permeability and the coercive field are obtained from this Barkhausen signals. The angular dependence of these macroscopic magnetic properties is studied. The tension for which the magneto-elastic energy balances the anisotropic energy is estimated. The results are discussed based on the domain wall theory.     

Modelling of plastic flow, heat transfer and microstructural evolution during rolling of eutectoid steel rods

A study was undertaken in an attempt to quantitatively describe the rolling process of eutectoid steel rods. Finite element method was employed to model plastic flow and heat transfer in the deformed material, and heat transfer during cooling to ambient temperature. The numerical calculation gave an assessment of the strain, strain rate and temperature distributions in the work piece. This allowed the prediction of the austenite microstructure evolution during the process. Finally, the relationships describing the microstructure-mechanical properties were used to quantitatively characterize the influence of processing parameters on strength of rods after rolling.     

深冷处理与工模具的耐磨性

热处理后的金属材料再经低落曙处理，其力学能明显提高，尤其是高碳高合金工模具钢的耐磨性提高特别显著。本文着重研究了应用面较广的Ｗ６Ｍｏ５Ｃｒ４Ｖ２钢的处理工艺制度，组织性能及其磨损机理。     

数控机床主轴部件变形的有限元分析

利用有限元分析方法进行优化设计,在产品设计阶段就能对主轴部件静、动态特性作出符合实际的预测,使数控机床主轴部件实现优化设计,进而提高产品一次设计成功率、缩短产品开发周期,提高数控机床产品的设计水平.     

机床液压系统故障树分析

应用故障树分析法对某厂一台机床液压系统的典型故障进行了故障树分析，取得了满意的结果。实践证明，将故障树分析法应用于机床液压系统故障诊断中是非常有效的。     

Drawing of square twisted wire

The shape of the deformation zone during drawing of square twisted wires is described in this paper. The condition of the stable deformation of the wire is formulated. This condition is satisfied by the constant value of the pitch of the helical surface of the die. The work focuses on the investigation of the influence of the die cone angle on the drawing parameters, in particular on the drawing stress.     

机床故障诊断系统知识表示的研究

针对所研究的机床故障诊断专家系统，以故障树分析法为基础，采用面向对象的事件知识表示方法。并以面向对象编程技术给出了知识表示的示例。分析了这种知识表示方法的特点。实践证明，这种知识表示方法在故障诊断专家系统中是确实有效的，而且这种表示方法融合了多种传统知识表示方法的长处，是一种值得研究与应用的方法。     

灰色系统建模理论在机床主轴疲劳寿命设计中的应用研究

运用灰色系统的理论及方法，将疲劳应力与寿命的相互制约关系看成一个灰色系统，将疲劳试验的应力水平均匀分成数级，并找出与之对应的安全寿命的白化值。通过对安全寿命值数列的一次累加，生成一个光滑离散函数。据此建立灰色系统模型，并求解灰色系统的微分方程 。通过残差模型的修正，提高模型精度，再运用灰色系统模型的还原模型，可计算出任一应力水平下的安全寿命值。为机床主轴的安全寿命计算提供了新的途径，具有较大的推广应用价值。     

机床圆柱结合部的动态特性解析方法

在机床图纸设计阶段，预测机床整机的动态特性具有十分重要的意义，进行机床整机动态特性预测的难点在于如何确定结合部的刚度和阻尼参数，本文以机床结构中应用较普遍的圆柱结合部为例，研究了基于结合面基础特性参数的圆柱结合部动态特性解析方法，并编制相应解析软件，给出应用实例，证明本文的方法及软件是正确的。     

机床电力拖动脉冲宽度调制技术的研究

本文重点介绍用于机床电力拖动系统中的电机脉冲调制(PWM)技术，在分析现有脉冲宽度调制技术的基础上，提出一种采用优化技术生成PWM调制波的方法，推导了优化PWM调制波的求解过程，给出了其计算公式。