探讨卧式容器鞍座位置对筒体受力分析的影响

卧式容器在工业生产领域广泛应用，保证卧式容器结构的安稳性，才能正常发挥出功能作用。本文针对卧式容器鞍座位置的设计进行探究，从鞍座结构要求和筒体受力计算入手，分析了鞍座位置对筒体受力的影响，并结合计算实例进行阐述。结果表明，卧式容器鞍座位置对筒体受力具有明显影响，提示设计人员根据容器的受力特点，对鞍座位置进行合理设计，必要时采用加强设计方案，以保证卧式容器的使用安全性。     

满水工况下三鞍座卧式容器临界长径比的研究

卧式容器筒体长径比对鞍座个数的设置有显著的影响,为了确定鞍式支撑卧式容器双鞍座与三鞍座支座设计的临界长径比,本文采用有限元法,对满水工况下不同长径比的双鞍座与三鞍座卧式容器筒体中危险截面的Tresca当量应力、周向应力和轴向应力进行分析,并基于各应力判据和不同厚度模型筒体中的Tresca当量应力、局部膜应力和轴向压应力曲线的交点确定了不同厚度卧式容器三鞍座设置的合适长径比。研究结果表明,筒体厚度较薄时,三鞍座卧式容器临界长径比可取L/D=12;筒体厚度较厚时临界长径比趋于L/D=10。     

三鞍座卧式容器鞍座许用沉降量研究

随着卧式容器的大型化发展,三鞍座卧式容器得以广泛应用。论文基于NB/T 47042-2014标准及轴向弯矩极限值给出了鞍座许用沉降量[e_1]、[e_2],在此基础上采用ANSYS软件建立了含不同沉降的三鞍座卧式容器有限元分析模型,考察了鞍座沉降量对筒体鞍座连接处最大应力的影响。研究结果表明:正向沉降量对筒体应力影响大于负向沉降量,基于轴向弯矩极限值得到的许用沉降量[e_2]对筒体最大应力影响过于显著;结合标准的许用沉降量[e_1],考虑正负沉降量对筒体最大应力影响的差异,给出了较为合理的鞍座许用沉降量值。     

卧式容器有限元分析及其结构优化设计

以Φ3750 mm/16 m多鞍座卧式压力容器为例,对结构进行设计及有限元强度分析。利用ABAQUS软件数值模拟了2种典型工况下容器应力和变形,对优化前后容器的强度和刚度进行分析及对比。计算结果表明,预紧工况和正常工作工况下,此卧式储罐的最危险位置均发生在筒体与法兰的焊接处,平盖处受力次之,有局部应力集中现象。通过优化卧式容器局部结构(平盖和筒体的钢板厚度),达到了减轻自重、提高强度和刚度的效果。     

大型球磨机筒体应力与应变有限元分析

筒体,是磨机工作的重要部分,其刚度和强度对球磨机的使用寿命和工作精度影响很大.过去的校核方法是将筒体简化为简支梁,再按照理论力学平面应力分析进行计算.这种计算方法得到的结果,精度不高,不能准确的反应其受力分布和变形情况.针对球磨机关键部件传统强度计算结果精确性差的问题,以筒体为研究对象,采用有限元方法进行应力与应变的有限元分析,确定筒体的应力分布和变形情况,旨在为结构优化设计提供参考.仿真结果表明,筒体的设计参数能够满足生产强度,与传统的计算结果相比,计算精度有所提高.筒体的设计安全系数比实际生产所需值大,在保证生产可靠性的前提下,可以适当的减少衬板厚度,降低制造成本.     

关于卧式容器设计中的问题

在“设计规定”第七章卧式容器设计,7.3.4鞍座处的周向应力中, b.在鞍座边角处     

大型多鞍座卧式容器设计方法分析

为降低弯矩和鞍座反力,长径比大的卧式容器大多采用三鞍座或多鞍座支撑。多年来,多鞍座卧式容器的设计并没有形成统一的标准,目前大多采用三弯矩理论计算弯矩和鞍座反力,再引用双鞍座卧式容器的Zick校核方法对应力进行校核。此种方法步骤复杂,不便于工程应用。最近,欧洲协调标准EN13445《非直接受火压力容器》提出了一种不同于传统方法的多鞍座卧式容器的最新设计方法,这是多鞍座卧式容器设计第一次正式写入标准。本文主要介绍EN13445中的多鞍座卧式容器设计方法与传统方法的不同,并对两种设计方法中存在的一些问题进行了探讨。     

碟形封头与筒体连接处边缘应力的研究

对一台实际的受压容器进行研究,用电测法测量在不同的压力下碟形封头和筒体连接处的应变值,并经过所编制的程序进行计算得到真实的应力值;同时通过薄膜理论计算得到相应的测试点的薄膜应力,然后对两种应力分析,探讨了薄膜应力计算公式的正确性,验证了碟形容器的应力计算方法,对实际容器应力的测定有指导意义.分析表明:在连接处或者不连续区应力会发生变化,而且在某些点应力会急剧增大.     

椭圆封头与筒体过渡段应力分布

在中低压容器常规设计中，对椭圆封头与筒体过渡段的边缘应力一般不予计算，只在结构上进行局部处理。为了探究边缘应力对椭圆封头及筒体过渡段的影响，文中针对5种不同直径的椭圆封头，采用ABAQUS有限元分析软件和有矩理论，对比研究了封头过渡段内外壁面应力的变化规律，同时采用有矩理论研究了封头过渡段内外壁面边缘应力的影响范围及最大值出现的位置。结果表明：5种不同直径封头直边段内外壁面存在大小相等、方向相反的边缘应力，内外壁面最大径向边缘应力与筒体薄膜应力相当，最大值至连接处的距离远大于椭圆形封头标准规定的直边高度，直径越大，距离越远。封头标准GB/T 25198—2010中规定直边高度处径向应力超出筒体薄膜应力的44%～61%。直边段与筒体薄膜应力相当的横截面距连接处0～15 mm,与直径关系不大。研究结果可对中低压容器的设计制造和安全运行起到一定的指导作用，为封头标准的修订提供参考依据。     

卧式容器的计算方法及其与各国规范的差异

一、卧式容器的计算方法卧式容器的设计,除按常规计算筒体、封头外,还应验算支座处的局部应力。此局部应力由于它的作用范围比较大,还不能都应用英国标准BS5500(1983年版)的附录G.2(或WRC107会刊)所推荐的局部应力计算方法。支座处的局部应力的计算方法,在很大程度上取决于支座的结构型式。众所周知,支座型式大致可分为三种:鞍式支座、圈座和支腿式支座。石油、化工装置中的卧式容器多置于两个鞍式支座上。对于鞍式支座支承的卧式容器,看起来受力简单,但山于容器重量和支座反力所引起的局部应力的计算还是很复杂的。目前,关于鞍式支座支承的卧式容器的局部应力的计算方     

气缸密封性能的非线性接触分析

针对某高功率密度柴油机的气缸盖-气缸垫-气缸套-机体密封系统,建立装配体的有限元三维模型。采用非线性接触分析法,研究发动机功率密度提升后,在预紧工况下气缸垫参数设置对气缸密封仿真计算的影响,对气缸垫密封面的接触应力进行有限元分析,对结构的密封性能通过静态面压试验进行评价。结果表明:采用非线性接触边界条件进行有限元分析,更能体现气缸盖、气缸垫与机体接触面的真实应力,因此非线性接触分析法是研究气缸密封的一种有效途径。     

发动机活塞与缸体的非线性接触分析

创建发动机活塞与缸体的接触区域的有限元模型;在缸体和活塞上施加约束和栽荷,建立力学模型;通过对活塞与缸体的接触区域的应力和应变分析,证实发动机工作时,活塞与缸体接触区域的强度和刚度足够.     

The temperature distribution due to frictional heat generated between a stationary cylinder and a rotating cylinder

An analytical model has been developed to find the distribution of heat between two cylinders placed at right angles to one another. One cylinder is stationary and the other rotates at high speed. The model assumes that the contact width is very small compared with the overall dimensions of the cylinders. The heat conduction problem has been solved for both the rotating and the stationary cylinder, the average temperature over the contact area has been determined and the heat distribution between them obtained by matching the average temperatures. Allowance has been made for surface heat transfer from both bodies.     

圆柱正弦活齿传动接触强度的模糊可靠性研究

基于模糊数学方法和可靠性设计理论,将应力和强度分别视为随机变量和模糊变量,建立了零件接触强度的模糊可靠性数学模型和计算公式,并对圆柱正弦活齿传动进行了接触强度的模糊可靠性分析和实例计算。     

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.     

气动平衡器O形密封圈与气缸润滑特性分析

为了降低O形密封圈与气缸内壁之间的摩擦力,气动平衡器装配过程中在气缸内壁涂上一层润滑脂。基于脂润滑相关理论,构建O 形密封圈和气缸的有脂润滑运动方程,通过MATLAB中PDE模块求解脂润滑模型,得出膜厚、接触应力在密封圈与气缸接触方向上的变化规律。基于ANSYS建立密封圈的瞬态结构有限元分析模型,以密封圈的运动速度和工作压力为恒定条件进行数值模拟,得出不同压缩率、摩擦系数以及行程方式条件下最大接触应力的时域特性。     

Photoelastic measurements and computation of the stress field and contact pressure in a pneumatic lip seal

This work regards the analysis of the structural behaviour of a typical elastomeric lip seal for pneumatic cylinders under actual working conditions. In situations of relative motion between the lip seal and the cylinder, coulombian friction is taken into account. The analysis has been carried out by means of both numerical and experimental methods. In particular, the behaviour of the seal with respect to the two contact zones, i.e. between seal and rod and between seal and mounting housing, has been studied. In order to describe the seal stress and strain fields, isoclinic lines and isochromatic fringes have been determined both by means of a two-dimensional finite element model and by reflection and transparent photoelastic methods. The contact pressure between the lip seal and the rod has been computed numerically, with the FEM model and analytically from photoelastic data. The comparisons between experimental and numerical data have permitted numerical model validation.     

衬套过盈装配贴合率检测技术

针对衬套过盈装配面,提出一种无需涂抹红丹粉的机械装配面贴合率检测方法。将装配面的接触简化成粗糙的差表面与理想的刚性平面的接触,根据薄壁圆筒与厚度圆筒弹性过盈配合的计算原理,推导出接触变形量的计算公式,计算出装配面的贴合率。检测结果可真实反映试验模型过盈装配面贴合区域分布情况,为分析试验模型过盈装配的可靠性提供依据。     

盾构推进液压缸刚度有限元分析

以实际盾构推进液压缸为研究对象,通过Pro/E软件建立液压缸的三维模型,利用ANSYS软件建立了球铰的刚度与液压缸的刚度的有限元模型,得出液压缸刚度与载荷成线性比例的关系。为盾构推进机构的刚度分析和推进系统的设计提供了一定的基础。     

A Finite Element Study of an Elasto-Plastic Disk or Cylindrical Contact Against a Rigid Flat in Plane Stress with Bilinear Hardening

This work presents a finite element study of elasto-plastic cylindrical contact. The geometry could also be described as a vertically aligned disk whose axis of symmetry is parallel to the contact surface. The cylinder is considered to be in the plane stress state. The material of the cylinder is modeled as elasto-plastic with bilinear hardening (also known as linear hardening). Simulations for a range of material properties and deflections typical to engineering applications are carried out. A mesh convergence study has also been performed. By employing symmetry, the cylinder has been modeled as a quarter circle and a straight line is used to model the opposing rigid flat surface. The finite element results for the elastic and fully plastic cylindrical contact cases are compared to other existing models such as Hertz contact and spherical elasto-plastic models. Since the case considered is plane stress, the stress distribution is significantly different from elasto-plastic spherical contacts, which would be closer to a plane strain case. An empirical relationship is fit to the results to allow for prediction of the contact width as a function of displacement and force.