渐开线圆柱齿轮横截面的几何性质

本文应用渐开线方程，导出了渐开线圆柱齿轮在非受力状态下，横截面上轮齿及整个截面的面积、形心和惯性矩的准确计算式。     

渐开线圆柱齿轮修形量的可靠性计算

在渐开线圆柱齿轮传动的外载和齿轮精度一定的条件下，通过给定动载系数ＫＶ值，用可靠性方法确定齿轮的修形量，可达到基本控制齿轮传动的冲击动载，改善齿轮传动动态性能的目的。另外附有裤例计算可供参考。     

渐开线齿轮传动过渡曲线干涉问题的分析及处理

提出了渐开线齿轮传动过渡曲线干涉的概念,分析了发生过渡曲线干涉时对齿轮传动的影响以及发生的原因,并且找出了防止干涉的一般方法。     

少齿数渐开线齿轮副啮合区域的研究

本文讨论了渐开线齿轮传动的啮合区域,提出了少齿数渐开线齿轮副节点外啮合时,齿面接触强度应以实际啮合线的中点作为计算点,并提出 了节点外啮合的判定条件;推出了在实际啮合线中点啮合时综合曲率半径的计算公式;最后通过一个实例,说明以节点和实际啮合线中点为计算点时二者之间的误差。     

渐开线齿轮NGW型行星传动的啮合效率研究

这里对ＮＧＷ型行星齿轮机构的啮合效率进行了研究。深入分析了公共行星齿轮在工作过程中受力与运动关系，推导出其啮合效率表达式。这里的公式有助于此类机构效率的理论计算，啮合效率的值可以从理论上确定，而不需要再取为近似值。     

齿轮渐开线起测点计算及其应用软件

本文讨论了几种齿轮啮合情况下如何计算渐开线起测点长度的问题．作者从检查７级以上齿轮时需测量的渐开线起测点长度出发，总结出一套行之有效的计算公式，并用Ｃ语言调试成功一套应用软件．     

滑移线在塑性变形中的应用

本文利用塑性变形过程的特点，建立了滑移线场，由滑移线的几何性质来确定应力分力。它避开了直接用非线性塑性本构关系，因此极大简化了计算过程。     

深井软岩表面变形随围岩性质变化分析

依据理论分析得出的圆形巷道围岩表面变形计算公式,分析了原岩性质对围岩表面变形影响。分析结果表明：随原岩应力增加,不同岩性围岩表面变形增长速率不同,深井软弱围岩表面变形显著;通过注浆法改变围岩性质,提高围岩粘结力和内摩擦角是减少围岩表面变形,保持围岩稳定较为有效的手段。     

塑性变形对单晶铜线材导电性影响的研究

为了研究塑性变形对单晶铜线材导电性的影响，以及电阻率与塑性变形量之间的定量关系，将Φ8mm的工业单晶铜线材冷拔后，得到塑性变形量不同的试样，用四端引线法精确测量其电阻率、结果表明，单晶铜线材的电阻率随塑性变形量的增加而上升，其原因是由于单晶铜线材的微观组织畸变程度随塑性变形量的增加而加剧。     

Effect of plastic deformation on diffusion-rolling bonding of steel sandwich plates

Diffusion bonding is one of the most important techniques for composite materials, while bonding temperature, holding time, and rolling reduction are the key parameters that affect the bonding strength of sandwich plates. To study the effect of plastic deformation on the bonding strength, laboratory experiments were carried on a Gleeble Thermal Simulator to imitate the diffusion-rolling bonding under different reductions for steel sandwich plates. The bonding strength and interlayer film thickness were measured, and the element diffusion was analyzed using line scanning. The relationship between the bonding strength and ＂diffused interlayer＂ thickness was investigated. It has been found that the bonding strength increases with reduction, whereas the interlayer film thickness decreases gradually as the reduction increases. The diffusion under plastic deformation is obviously enhanced in comparison with that of nil reduction. The mechanism of plastic deformation effect on the diffusion bonding and related models have been discussed.     

塑性接触对表面形貌的影响

针对工程中许多接触表面(如机床静结合面)的接触特性(如接触面刚度等)都决定于塑性接触后的表面形貌的情况,本文研究了塑性接触对表面形貌的影响,提出了相应的计算模型,并考虑了法向载荷与切向载荷的影响。该模型不仅为研究静结合面(这种结合面塑性接触后的表面形貌是无法测定的)接触特性提供了有效方法,而且对于合理选择精整加工的最佳工艺参数具有指导意义。     

Effects of ultrasonic vibration on plastic deformation of AZ31 during the tensile process

An investigation on the plastic behavior of AZ31 magnesium alloy under ultrasonic vibration(with a frequency of 15 kHz and a maximum output of 2 kW) during the process of tension at room temperature was conducted to reveal the volume effect of the vibrated plastic deformation of AZ31.The characteristics of mechanical properties and microstructures of AZ31 under routine and vibrated tensile processes with different amplitudes were compared.It is found that ultrasonic vibration has a remarkable influence on t...     

塑性变形条件下拉伸构件的磁记忆效应

通过对经退磁处理的光滑和切口试件在不同程度拉伸变形下的在线磁信号的测量,研究了塑性变形对磁记忆效应的影响.光滑试件在弹性和均匀塑性流动阶段磁场分布近似为斜直线,仅到颈缩后才在应力集中部位产生明显的磁场畸变;切口试件在屈服以后即出现畸变特征,基于位错理论分析了异常波波高增加的原因,利用磁信号水平线图可定性判断应力集中区破...     

High temperature plastic deformation behavior of non-oriented electrical steel

High temperature plastic deformation behavior of non-orientated electrical steel was investigated by Gleeble 1500 thermo-mechanical simulator at strain rate of 0.01−10 s⁻¹ and high temperature of 500–1 200 °C. The stress level factor (a), stress exponent (n), structural factor (A) and activation energy (Q) of high temperature plastic deformation process of non-orientated electrical steel in different temperature ranges were calculated by the Arrhenius model. The results show that, with dynamic elevation of deformation temperature, phase transformation from α-Fe to γ-Fe takes place simultaneously during plastic deformation, dynamic recovery and dynamic recrystallization process, leading to an irregular change of the steady flow stress. For high temperature plastic deformation between 500 and 800°C, the calculated values of a, n, A, and Q are 0.039 0 MPa⁻¹, 7.93, 1.9×10¹⁸ s⁻¹, and 334.8 kJ/mol, respectively, and for high temperature plastic deformation between 1 050 and 1 200 °C, the calculated values of a, n, A, and Q are 0.125 8 MPa⁻¹, 5.29, 1.0×10²⁸ s⁻¹, and 769.9 kJ/mol, respectively. Foundation item: Project(2005038560) supported by the Postdoctoral Foundation of China; Project(05GK1002-2) supported by Key Program of Hunan Province     

Influence of stress path change on the resistance to plastic deformation of cold rolled sheets

Flat workpieces have been tested in order to investigate the influence of stress path change （loading mode） while keeping strain path unchanged. These investigations are pertinent to the testing of cold rolled strips and to subsequent forming. The workpieces which first compressed by plane strain compression in thickness direction were then tested in perpendicular direction in order to measure the influence of strain and stress path. The tension workpieces came from flat die compression test at different deformation histories. Two different materials were investigated： 18/8 Ti stainless steel and AW-1050 aluminium. The results show that the plastic flow by tension in lengthwise direction after pre-strain by compression in thickness direction will begin at an appreciably lower stress than that of the workpieces unloaded after pre-compression. Comparing with two materials, it can be seen that both 18/8 Ti stainless steel and AW-1050 aluminium behave similarly. The drop in yield stress is lower for AW-1050 aluminium than that for 18/8 Ti stainless steel. However, reloading in different directions than in the precious step results in significantly higher strain hardening.     

Experimental study on the free surface deformation in the oxide melt

1 Introduction The convective motion induced by local variations of surface tension along a liquid free surface is called Marangoni convection. Flows driven by a temperature gradient aligned parallel to the free surface are often named thermocapillary convection, which is often a dominating effect in material processing techniques. It is well known for the melt crystal growth that the thermocapillary convection becomes instable at high Marangoni numbers, which gives rise to temperature oscill…