三维空间多节万向传动轴扭振的分析计算

对三维空间多节十字轴万向节传动轴系统扭转振动的特性进行了分析探讨,用渐近法讨论了系统参数以及扭振的主、从动件旋转非等速性等因素对动力放大系数的影响,提出了为减小动力放大系数和降低旋转的非等速性进行优化设计传动件刚度、转动惯量、轴间夹角及十字轴转角相位差等方法。按此法设计计算三维空间多节万向传动轴可减轻系统扭振及避免共振。     

微型汽车前舱横梁的刚度分析

分析了某型号微型汽车的前舱横梁在前舱盖锁闭力作用下的变形情况,针对扭转刚性不足的问题,通过有限元对比分析的方法得出了较优的设计方案。     

Analytical Method for Evaluating Ultimate Torque of FRP Strengthened Reinforced Concrete Beams

The behavior of fiber reinforced polymer (FRP) strengthened reinforced concrete beams subjected to torsional loads has not been well understood compared to other loads. Interaction of different components of concrete, steel, and FRP in addition to the complex compatibility issues associated with torsional deformations have made it difficult to provide an accurate analytical solution. In this paper an analytical method is introduced for evaluation of the torsional capacity of FRP strengthened RC beams. In this method, the interaction of different components is allowed by fulfilling equilibrium and compatibility conditions throughout the loading regime while the ultimate torque of the beam is calculated similarly to the well-known compression field theory. It is shown that the method is capable of predicting the ultimate torque of FRP-strengthened RC beams reasonably accurately.     

Effect of free-end torsion on microstructure and mechanical properties of AZ31 bars with square section

In this study, a rolled AZ31 bar with square section was used. The reciprocating torsion was performed to maintain the shape of the sample. The microstructure evolution of AZ31 bar during torsion and its influence on compressive anisotropy were investigated in detail. Results showed that reciprocating torsion can simultaneously enhance yield strength in three compressive directions, and reduce compressive anisotropy. Reciprocating torsion generated profuse dislocations and {10–12} twin boundaries to harden the micro-hardness and yield strength. Reciprocating torsion can also generate new texture component which is mainly from the orientation of newly generated {10–12} twins. The new twin-structures will be responsible for the reduction in compressive anisotropy. Moreover, uneven deformation features in twisted sample were systematically investigated.     

汽油机试验台架传动系统扭振问题的研究

本文首先通过对某1.4L汽油机进行扭振分析,然后对无离合器和变速箱的汽油机的台架进行扭振测试,对信号处理结果与模型计算进行分析比较,对比结果说明,扭转振动分析模型合理。在此基础上,研究了联轴器参数对系统扭转振动的影响规律,给出了系统扭转振动改进的方向和建议方法。     

某发动机共振异响诊断与消除

测试了某异响发动机工作时的声压和振动加速度,通过异响工况下的加速度功率谱密度曲线结合曲轴自由模态分析结果诊断出了异响问题的原因-曲轴共振。对引起共振的激励源-发电机及点火系统进行改进,使激励能量足够小从而消除了该发动机的异响。该共振异响问题的解决,对类似问题具有参考和指导意义。     

HPVC扭结膜吹塑性研究

对HPVC扭结膜吹塑过程进行了研究,推导了膜泡在冷却线处纵、横方向的应力σ_(11t)和σ_(22t)与加工条件的关系式,在无需求出膜厚的条件下,由压折辊处的牵引张力、牵伸比、吹胀比、材料密度、冷却线高度、膜泡内外气压差求出σ_(11t)和σ_(22t)。理论与在各种吹胀比和牵伸比下得到的薄膜性能对比性较好。     

Elastic notch stress intensity factors for sharply V-notched rounded bars under torsion

The paper deals with the determination of analytical expressions for the mode III notch stress intensity factors for circumferentially-sharply-notched rounded bars under torsion loading, starting from the theoretical stress concentration factors of the corresponding notch problem.An exact, closed-form solution for the NSIFs is obtained for deep notches; subsequently the solution is extended also to finite notched components taking advantage of a shape function determined by a numerical best fitting procedure.     

单片机在扭矩测量中的应用

本文介绍一种扭矩测量系统，它使用单片机、磁电式扭矩传感器和简单的电路实现扭矩的测量，具有结构简单、性能稳定、抗干扰、精度高等特点。     

Torsion of an elastic non-homogeneous layer by two circular discs

Two circular discs of different radii on the opposite faces of an infinite, non-homogeneous elastic layer, whose rigidity is assumed to vary with two cylindrical coordinates r, z by a power law (% MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbnL2yY9% 2CVzgDGmvyUnhitvMCPzgarmWu51MyVXgaruWqVvNCPvMCG4uz3bqe% fqvATv2CG4uz3bIuV1wyUbqee0evGueE0jxyaibaieYlf9irVeeu0d% Xdh9vqqj-hEeeu0xXdbba9frFf0-OqFfea0dXdd9vqaq-JfrVkFHe9% pgea0dXdar-Jb9hs0dXdbPYxe9vr0-vr0-vqpWqaaeaabiGaciaaca% qabeaadaabauaaaOqaaiabeY7aTjabg2da9iabeY7aTnaaBaaaleaa% cqaHXoqycaGGSaaabeaakiabek7aInaaCaaaleqabaGaeqiXdq3aaW% baaWqabeaacqaHXoqyaaWccaWG6bWaaWbaaWqabeaacqaHYoGyaaaa% aaaa!4CAB!\[\mu = \mu _{\alpha ,} \beta ^{\tau ^\alpha z^\beta } \]), are forced to rotate through two different angles of rotation. The rest of each surface is kept stress free. Using the Hankel integral transform, this problem is shown to lead to two pairs of dual integral equations, the solution of which is governed by two simultaneous Fredholm integral equations of the second kind. The latter may be solved either numerically or by iteration (in the case of sufficiently large values of the layer's thickness compared to the maximum of the radii of the circles and for =0). The solutions for some particular cases previously investigated are recovered by assigning specific numerical values to physical and geometrical parameters.Expressions for some quantities of physical importance, such as the torques applied on the two surfaces and the stress intensity factors, are obtained for the two surfaces and some numerical values are displayed graphically.