横向外压环向加强圆柱形容器的优化设计

问题的提出用加筋的办法来提高外压设备的承载能力近年来已为多数工业国家研究和应用。加筋圆柱壳是正交异性圆柱壳的一种,它是在圆柱壳的内侧或外侧加用一定间距的环向筋或纵向筋或二者兼有(又称蜂窝筋)(图1)。以提高壳体     

横向外压环向加强圆柱形容器的优化设计

一、问题的提出用加筋的办法来提高设备的承载能力近年来已为多数工业国家研究和应用。加筋圆柱壳是正交异性圆柱壳的一种,它是在圆柱壳的内侧或外侧加用一定问距的环向筋或纵向筋或二者兼有(又称蜂窝筋)(图1),以提高壳体的劲度,降低设备的重量。 1966年苏联列宁格勒化工机械研究院对某真空容器环向加筋电算了六种方案,数据详见     

复合材料加筋圆柱壳的低频声散射特性研究

采用有限元/无限元相结合的方法对复合材料加筋圆柱壳以及金属加筋圆柱壳低频声散射特性进行了仿真分析。计算了不同波数情况下加筋圆柱壳和非加筋圆柱壳的散射情况,其中加筋情况分别采用了两种处理方法,包括梁单元建模与壳单元建模,结果表明加强筋的建模方法对于计算结果产生了一定影响,在一些频率点甚至十分显著。     

大开口高承载网格加筋壳的设计与工艺

本文采用有限元法计算了承受高轴压和外压作用下的大开口复合材料纵横密加筋壳的稳定性，得出不同铺层角度、不同受力工况下的大开口圆柱壳的临界载荷，并采用1：1试验件进行试验验证，将计算值与实验值进行了比较；对大开口复合材料纵横密加筋壳的缠绕工艺进行了研究，解决了大开口网格加筋壳开口补强的一次成型技术和密筋及开口部分的多丝嘴、无增量、非线性机械化缠绕成型工艺技术。     

嵌入式阻尼环筋开口圆柱壳的振动性能分析

本文在应用一阶剪切变形壳理论的基础上,采用共固化工艺的嵌入式阻尼复合材料环筋开口圆柱壳作为研究对象,加强筋作离散元素处理,对此结构的动态特性进行了研究。应用Rayleigh-Ritz能量法和Navier双级数法,推导嵌入式共固化阻尼复合材料环筋开口圆柱壳的应变能和动能表达式,建立其自由振动的控制方程;另外,利用ANSYS建模获得此结构的模拟结果,对两者结果进行了比较,验证了本文方法的有效性。探讨了不同筋条高度及阻尼夹芯层厚度对本文所述环筋开口圆柱壳性能的影响。研究结论对轻质高刚度大阻尼的复合材料结构件的设计及应用有一定的参考价值。     

复合材料加筋壁板优化设计

对于复合材料加筋壁板稳定性优化问题,由于涉及多个设计变量:筋条数目、筋条间距、筋条高度、筋条的铺层参数、面板的铺层参数等,本文采用具有多参数级联编码方式的遗传算法时基于稳定性设计要求的加筋壁板进行了优化.对复合材料T型加筋壁板结构重量优化的算例,验证了本文所用方法的有效性.     

含损伤复合材料加筋板强度分析及修补研究

对含损伤复合材料加筋板进行了强度分析及修补研究。建立了复合材料层合加筋壁板的有限元分析模型,该模型采用界面单元以有效模拟筋条和壁板之间的连接界面及层板分层界面,连接界面和复合材料层板分别采用Quads和Hashin失效准则作为失效判据,引入材料刚度退化模型,采用非线性有限元方法,研究了复合材料加筋壁板在压缩载荷下的破坏过程。建立了筋条脱粘面积、层板分层面积与结构承载能力之间的关系,对不同损伤加筋板进行了修补研究,研究结果可为合理制定复合材料构件缺陷验收标准和结构修理容限提供分析依据。     

多轴向复合材料加筋壁板的定位及成型

针对复合材料多轴向加筋壁板提出了一种框架式的模具定位结构。在蒙皮成型模具上设置一个定位框架,从框架的梁上定位筋条成型模具。模具结构简单、操作方便并且采用特殊的真空袋封装方式可以成型出筋条尺寸精度高、位置精确的复合材料加筋壁板。     

轴压作用下缠绕复合材料夹芯圆柱壳力学性能研究

为研究缠绕复合材料夹芯圆柱壳的力学特性,首先开展了缠绕复合材料夹芯圆柱壳模型的轴向压缩试验,得到载荷-位移曲线与应变分布规律;进而,依据复合材料经典层合板理论,将缠绕圆柱壳模型的内外蒙皮均匀化,等效为单向纤维增强复合材料,采用ABAQUS有限元软件对结构模型进行分析,得到不同载荷下的应变规律;最后,将有限元计算结果与试验结果进行对比,轴向刚度误差为10.69%,测点应变值最大误差为12.88%,表明该方法可用于缠绕复合材料夹芯圆柱壳计算,为复合材料夹芯圆柱壳的设计应用提供指导。     

双曲率复合材料帽型加筋壁板自动化制造技术研究

具有大开口窗框、帽型长桁双扭曲爬坡结构特征的双曲率复合材料帽型加筋壁板是中后机身段曲率变化最大的部位。通过试验件制造开展了原材料智能仓储物流系统、自动铺丝和铺丝轨迹规划、自动铺带和热隔膜自动化成型帽型筋条、筋条定位、柔夹数控加工工艺性研究,文章验证了双曲率复合材料帽型加筋壁板的自动化制造技术的可行性。研究表明,双曲率复合材料帽型加筋壁板自动化制造技术能满足材料工艺要求和验收技术条件要求。     

压力容器稳定性分析

对于受外压的容器,除了圆筒、球壳、锥壳和有限定的开孔外,其他的很多形状以及不均匀的载荷等都无法按照现有的标准规范进行稳定性校核。通过分析结果的对比,确定了基于有限元屈曲分析为基础的压力容器稳定性分析方法和评判准则。     

Investigation of the high velocity impact behavior of grid cylindrical composite structures

In this paper, the experimental behavior of grid cylindrical composite structures, which are used widely in engineering structures, under ballistic impact is investigated. For this purpose, some grid cylindrical composite specimens were manufactured by the filament winding process and perforated by projectile using the ballistic gas gun. Incident impact velocity and exit velocities of projectile were recorded in each test. The results show that the presence of the ribs prevents pervading of damaged area of one cell to its adjacent cells. The structure behaves differently against projectile with velocity near ballistic limit and higher velocities. The results demonstrated that, by getting close to the ribs location, ballistic limit velocity was increased. However, due to reduction in energy absorption mechanisms in grid composite structures which are impacted in higher velocity than ballistic limit, projectile was exited of grid samples at higher velocity than unstiffened composite shells. Also, investigation of delamination in composite shell and ribs, debonding between ribs and shell (or separation of ribs and shell), residual velocity of projectile, damaged area of the grid specimens and the effects of curvature in two different velocities are presented and the results are discussed. POLYM. COMPOS., 38:2603–2608, 2017. © 2015 Society of Plastics Engineers     

功能梯度复合材料圆柱壳基本理论及长壳固有振动解

本文首先在功能梯度复合材料圆柱壳基本理论上将原始三维变系数控制方程转化为特殊类型各向异性及薄膜-弯曲耦联的二维常系数方程;对相当长圆柱壳提出轴向、周向分离变量振型函数,求取满足基本微分方程的固有振动解析解,得到功能梯度圆柱壳固有频率与振型分析的一般性方法,适用于任意功能梯度分布复合材料长圆柱壳。     

Effect of Shell Material on the Detonation of an Explosive Charge

The effect of shell material (copper and silicon carbide) on the detonation of a cylindrical explosive charge was analyzed. The wave patterns in the detonation products and the shells are substantially different, which is due to different sound velocities and the rapid destruction of the ceramic under explosive loading. The wave pattern at the explosive/ceramic interface was found to be affected by desensitization of the explosive due to its loading by an advancing wave from the shell side, resulting in a decrease in pressure, blurring of the detonation front, and an increase in particle velocity. Throughout the process, there is a continuous increase in the time of explosive decomposition near the interface between the explosive and the ceramic shell. An extended region with a constant pressure close to the Chapman–Jouguet pressure was observed on the axis of symmetry behind the detonation front of the explosive charge in the ceramic shell.     

开孔处应力集中系数的简化计算

由于各种工业和结构的要求,不可避免地要在压力容器上开孔并安装接管,开孔必然会造成器壁强度的削弱,其削弱程度的大小可通过应力集中系数的大小来体现。通过对平板上开小圆孔边缘处的应力计算分析,得出开孔处应力集中系数的简便计算方法。运用该方法可以准确的计算出球壳以及圆柱壳等壳体上开圆孔的应力集中系数,确定危险位置及应力的大小,为确保压力容器的安全提供必要的条件。     

Vergleich von Nachweisverfahren für Stutzen in Zylinderschalen unter Innendruck und äußeren Lasten

Various methods for the verification of nozzles in cylindrical shells are described and the results of an example are compared. The example is carried out according to DIN EN 13445‐3, Sect. 16.5, in which the maximum permissible loads from internal pressure, axial force as well as moments in the longitudinal and circumferential direction are calculated. The results are compared with finite element computations performed with a 3D shell model, both with linear‐elastic material behavior and as limit‐load analyzes with ideal‐elastic ideal‐plastic material behavior.     

圆柱壳开孔接管外压失稳临界压力参数化分析

外压圆柱壳开孔接管是工程中常用结构之一,研究失稳临界压力可为其结构设计提供依据。本文针对4个无量纲参数:筒体外径与有效壁厚的比值、筒体长径比、开孔率及接管与壳体有效厚度比,探究外压圆柱壳开孔接管结构失稳临界压力。运用正交试验设计方法,组合出49组不同参数的模型,采用特征值分析、几何和材料双非线性分析方法得到各分析模型的临界压力,并分析各因素对临界压力的影响。研究结果可为外压圆柱壳开孔接管结构设计提供借鉴。     

Template synthesis of composite hollow spheres using sulfonated polystyrene hollow spheres

In this paper, we propose a general template synthesis approach towards composite hollow spheres using sulfonated polystyrene gel hollow spheres. The gel hollow spheres are highly crosslinked to well preserve the spherical contour during template synthesis. It is important that the gel shell is infiltrative to many species to allow their further growth therein by specific interaction. The grown materials are well distributed thorough the whole shell forming composite shells. This method is general, which is proved by the growth of many representative materials for example metal Pd nanoparticles, magnetite Fe₃O₄ nanocrystallites, conducting polyaniline, and inorganic titania and silica. It is found that mesoporous inorganic shells are obtained after the template gel is calcined. This concept can be applied to other gel shells and grown materials expecting a new family of composite hollow spheres.     

Mid-Explosion Recovery of an Intermediate Phase of a Cylindrical Metal Shell

To understand the complex dynamic response of cylindrical metal shells under highstrain-rate loading, a mid-explosion recovery device is designed to recover cylindrical shells at an intermediary phase, chosen in this study to be the phase wherein cracks penetrate through the entire casing wall thickness. The surface dynamic processes of the expansion, fracture propagation, and rupture of a 40CrMnSiB steel cylindrical shell are measured with a high-speed framing camera for determining the appropriate inner diameter of the mid-explosion recovery device. The numerical simulation software Autodyn-3D is used to predict the influence of the device wall thickness and the maximum radial deformation of the device inner wall upon the outer fracture diameter of the casing. The casing at the desired phase is recovered by the device, and the outer diameter of the shell is found to increase by 1.77 times, while the radial deformation of the device is 5 mm. The crack distributions, the distance between the adjacent penetrating shear cracks, and the number of circumferential divisions are found to vary along the axis of the cylindrical casing.     

先进复合材料球冠壳体结构参数对稳定性影响

先进复合材料层合壳体在航空、航天、国防领域中获得广泛应用。本文结合复合材料球冠光壳的结构特点,基于有限元分析软件ANSYS,采用层合壳单元建立有限元模型,研究了先进复合材料球冠壳体矢径比、厚度、铺层角度对其稳定性的影响。