离心卸料离心机锥形转鼓筒体有限元分析与强度计算

锥形转鼓是离心卸料离心机的关键部件,其结构性能决定了离心机的分离性能.通过对某国产连续式离心分离机大直径锥形转鼓结构分析,采用有限元分析方法对转鼓及鼓壁开孔进行有限元建模和应力分析,对该锥形转鼓进行强度评定.研究结果对离心机锥形转鼓结构设计有一定的指导意义.     

离心机转鼓壁边缘应力的计算方法

根据假定的离心机转鼓的鼓底为刚体来计算鼓壁边缘应力，所得结果与试验数据相符。同时还提出了将相似方法用于鼓壁边缘的应力计算。     

卧式螺旋卸料过滤离心机转鼓开孔削弱系数的研究

开孔转鼓是卧螺离心机的主要部件,转鼓开孔后强度会削弱,因此,对于转鼓开孔削弱系数的分析研究是十分必要的。利用有限元分析软件ANSYS10.0对开孔转鼓进行参数化建模、网格划分、施加对称约束,然后进行强度应力分析,研究开孔转鼓强度应力的变化规律,转鼓开孔处会产生应力集中,最大应力也出现在开孔的位置。通过节点应力对比的方法,研究转鼓开孔后强度应力变化规律,获得产生的最大强度应力的数值和节点M的坐标,在未开孔转鼓体上找到与节点M坐标相同或者最接近位置点的Stress intensity值,通过对比方法获得转鼓开孔削弱系数。     

碟式分离机转鼓应力的无线测试与仿真对比研究

针对碟式分离机转鼓在运行情况下应力测试难的问题,在碟式分离机转鼓试验台上,对两种不同的结构(单个转鼓和转鼓组件)开展了无线动态应力测试,并结合有限元仿真进行了对比研究。采用Wi Fi无线通讯技术进行电阻应变测试实验,直接获得不同位置不同转速下的转鼓内壁应力应变数据,并与行业标准JB/T 8051-2008《离心机转鼓强度计算规范》和有限元仿真分析得到的结果进行对比分析。研究结果表明,将有限元法的计算结果和实验数据进行了比较,两者基本吻合;空转鼓旋转时,转鼓组件鼓壁内的环向应力大于单个转鼓鼓壁内的环向应力,而且随着分离机转速的提高,两者相差越大;单个转鼓的应力情况跟规范基本吻合,说明直接使用规范中的公式会有一定偏差。     

开孔圆筒形转鼓的应力及壁厚计算─—评《离心机转鼓强度计算公式探讨》

针对《离心机转鼓强度计算公式探讨》一文中对目前常用的开孔圆筒形转鼓应力及壁厚计算公式提出的一些不同意见,加以讨论。     

大型立式储罐罐壁开孔补强应力分析

简述了大型储罐罐壁开孔补强的基本设计原则.对比JB/T 4736-2002《补强圈》标准中有关材料强度及厚度的要求,得出现有大型储罐的第一圈罐壁材料强度及厚度均不符合该标准要求.采用有限元数值计算模拟了储罐开口补强处分别在有无补强圈、不同开孔直径以及不同接管内伸长度时开孔周边的应力分布规律,并根据计算结果,对比分析储罐大开孔补强与小开孔补强的特性差异.分析了罐壁开口补强处的应力分布规律,并得出了相关结论,为储罐设计者合理设计开孔补强提供参考.     

开孔圆筒形转鼓的应力及壁厚计算——评《离心机转鼓强度计算公式探讨》

针对《离心机转鼓强度计算公式探讨》一文中对目前常用的开孔圆筒形转鼓应力及壁厚计算公式提出的一些不同意见，加以讨论。     

带孔转鼓鼓身应力分布及孔沿应力集中研究

本文以SS-800离心机为例,研究了无载和有载两种工况下带孔转鼓的应力和变形,确定最大应力及变形的部位;探讨了转鼓开孔后强度削弱情况;分析计算了有孔转鼓的孔沿处的应力集中情况及最大应力和应力集中系数。     

卧式螺旋卸料沉降离心机转鼓的有限元仿真

应用VisualNastran有限元仿真软件对转鼓在各种载荷工况下的应力应变进行了仿真分析，并调整转鼓壁厚参数来研究参数的变化对转鼓的强度和径向变形的影响。仿真结果表明：转鼓的最大应力位于靠近大端鼓底的柱形筒体的内壁上；物料离心液压引起的最大应力和最大径向位移随着转鼓壁厚的减小而增大；转鼓自身质量离心力在壁内产生的最大应力和最大径向位移与鼓壁厚度无关。     

基于ANSYS的旋转床转鼓系统结构优化

为减小旋转床工作过程中转鼓的应力和变形,促进转鼓系统结构的改进,运用ANSYS软件建立旋转床转鼓系统有限元模型,进行静力学分析,得出转鼓正常工作状态下的应力分布。针对应力集中的部位和特点,改变局部结构,提出转鼓结构优化的有效措施。研究结果表明:最大变形在衬套与转鼓座接触处;在衬套中部存在应力集中现象;增大衬套壁厚、减小螺栓孔直径可以削弱该部位载荷。     

SIMULATION OF HOLE FLANGING PROCESS ON HEAVY CYLINDERS AND PARAMETER OPTIMIZATION

The forming mechanism of hole flanging on a thick-wall heavy cylinder forging is simulated by DEFORM3D. The cylinder is 4 390 mm in diameter and 390 mm in thickness. The results show that the compound deformation with bending and expanding happens in the process of hole flanging. The diameter of pre-hole of the workpiece is one of the key parameters in the process of hole flanging. The optimal diameter is obtained for reverse-conical hole of average diameter 40 mm by simulation of hole flanging process on 5 pre-holes with different diameters and 3 pre-holes with different shapes. The results can provide the scientific base for engineering application of the process.     

铝合金及复合材料板开孔损伤分析

分析计算了中心开孔损伤对铝合金板和不同铺层方式的复合材料板承载能力的影响。结果表明：在开孔尺寸一定的情况下，随着板宽的增大，开孔损伤板的应力集中因数减小；随着材料各向异性程度的提高，开孔损伤对板件的应力集中因数和承载能力的影响增大。这一结果在试验中得到证实。     

基于柴油发动机缸体缸孔精加工工艺的试验研究

缸体精加工对改善柴油发动机性能有显著影响,本文以缸孔底孔为例,介绍了一种半精镗-精镗复合镗刀工艺,可缩短调到时间、自动修正磨损、自动补偿误差,让缸孔底孔加工精度进一步提升.使用该工艺进行产品加工,缸孔直径满足设计要求;选择产品样件开展台架实验,结果表明缸套变形量在缸套磨损量范围之内,说明使用复合镗刀工艺进行缸体缸孔精加...     

Fatigue life investigation of solid and hollow rollers under pure normal loading

Two solid and hollow cylindrical rollers in pure rolling contact subjected to pure normal loading have been modelled. Using a finite element package called ABAQUS, the stress and strain distributions in the two rollers in contact have been determined. The relative fatigue life of the hollow rollers compared to solid rollers has been investigated using the fatigue life model for rolling bearings developed by Ioannides and Harris. Different hollowness percentages have been studied: 20, 40, 60 and 80%. The hollowness percentage is the ratio of the diameter of the hole to the outer diameter of the cylinder. Both cases were studied – when the two rollers in contact are hollow and when only one of them is hollow while the other one is solid. Making the rollers hollow will result in redistribution of stresses over a larger volume in the contact zone due to the flexibility of the hollow rollers. That decreases the peak stress in the contact zone of the hollow cylinder when compared to the solid cylinder. Hollow cylinders have more flexibility when subjected to normal loading. And so, the stresses are redistributed so that the fatigue life is improved. The best stress redistribution and so fatigue life improvements have been found when both cylinders have around 60% hollowness. Copyright © 2007 John Wiley & Sons, Ltd.     

制动主缸补偿孔位置检测误差分析与补偿

针对当前制动主缸补偿孔检测效率低、精度低、成本高等技术现状,提出了一种集光、机、电于一体的高性能精密检测系统,分析了该系统所涉及的补偿孔几何中心位置检测误差并进行补偿。通过对误差来源的分析,揭示了制动主缸补偿孔位置检测过程的误差解算方法。基于该解算方法,利用增量式误差补偿方法构建了误差补偿模型,并进行补偿孔检测与误差补偿实验。实验结果表明,系统竖轴误差对补偿孔直径检测数据的影响较小,而对补偿孔位置检测数据的影响则由补偿孔与基准面的相对位置决定。补偿孔与基准面距离越远,误差越大。实验数据显示,在型号为ZDZG-20.64的被试件中,被测补偿孔位置精度分别提高0.05 mm和0.254 mm;在型号为ZDZG-22.2的被试件中,被测补偿孔位置精度分别提高0.044 mm和0.072 mm。该误差模型及补偿方法能够有效提高制动主缸补偿孔的检测精度。     

大粗糙度气缸套内孔直径非接触测量方法研究

为解决大粗糙度的气缸套实现内孔直径自动化测量这一问题,基于电涡流传感器进行了测量方案的设计,并针对机械结构建立了测量过程的数学模型,得到了由机械结构引起的理论误差公式;通过MATLAB绘制出机械误差的三维曲面图,并得到了机械误差小于0.01 mm时各相关变量的取值范围;通过试验验证了自动测量机与内径百分表之间的测量误差...     

超细粉末硬化水玻璃砂的性能特征研究

采用课题组配置的超细复合粉末作固化剂,研究测试了超细粉末硬化水玻璃砂的性能特征,将它与目前大量采用的酯硬化水玻璃砂在性能上作了比较,并通过SEM对常温下和800℃焙烧后粉末硬化水玻璃砂样以及酯硬化水玻璃砂样的粘结桥微观结构进行了观察。试验结果表明：超细粉末硬化水玻璃砂工艺中,当水玻璃加入量占原砂质量的3%,粉末加入量占水玻璃加入量的25%时,砂样的常温强度比酯硬化水玻璃砂的强度提高约23%,残留强度降低约76%;粉末硬化水玻璃砂对水玻璃的模数敏感度不高,硬化过程中使用高模数水玻璃将显著改善水玻璃砂的溃散性和再生回用性能;粉末硬化水玻璃砂的抗湿性远远优于酯硬化水玻璃砂。     

挖掘机斗杆液压油缸安装孔平行度对油缸承载的影响分析

针对挖掘机斗杆液压油缸出现的"拉缸"问题,全面分析了导致"拉缸"的原因。利用力的分解模型,分析出了安装孔的平行度偏差对液压油缸承载的影响方式,利用ANSYS软件建立了斗杆液压油缸有限元计算模型,并计算出两种工况下液压油缸的应力分布云图,从而明确了平行度对液压油缸承载的影响程度。根据分析结果,对斗杆液压油缸的安装孔平行度进行了调整,改进后油缸"拉缸"反馈率明显下降。     

A simulation of the stress field in a tubular bone due to a forced-in shaft of a prosthesis

The state of stress and deformation in a hollow orthotropic non-homogeneous viscoelastic cylinder is determined assuming that a rigid shaft is pressed instantaneously in the hole of the cylinder. Axially symmetric plane stress fields are found in two limit cases: at the moment of loading and after an infinitely long time. A numerical example involving a standard linear model is examined in more detail, and the results displayed graphically.     

Stress Concentration in the Vicinity of a Hole Defect Under Conditions of Hertzian Contact

Two-dimensional photoelastic stress analyses were conducted for epoxy resin models containing a hole defect under the conditions of Hertzian contact. Stress concentrations around the defect were determined as a function of several parameters. These were hole diameter, its vertical distance from the contact surface, and the horizontal distance from the Hertzian contact area. Also determined was the effect of tangential traction (generated by a friction coefficient of 0.1) on the stress concentration.

Sharp stress concentrations occur in the vicinity of both the left and the right side of the hole. The stress concentration becomes more distinct the larger the hole diameter and the smaller the distance between the hole and the contact surface.

The stress concentration is greatest when the disk imposing a normal load is located at the contact surface directly over the hole. The magnitude and the location of stress concentration varies with the distance between the Hertzian contact area and the hole. Taking into account the stress amplitude, the area which can be involved in a process of rolling contact fatigue seems to be confined to a shallow region at both sides of the hole. The effect of tangential traction is comparatively small on the stress concentration around tile hole.