压力容器的球形封头和椭圆形封头的应力测定及分析

发布时间：2019-02-09 15:48

【摘要】：论文主要针对我国石油、化工、轻工、交通、食品、制药、冶金、纺织等传统部门所需的过程设备的关键部件-压力容器进行研究。压力容器可分解为筒体、封头、支座、开孔接管、密封装置、安全附件等，而封头的作用是提供所需的承压空间，根据几何形状的不同，封头可以分为球形、椭圆形、蝶形、球冠形、锥壳和平盖等几种，其中球形、椭圆形、蝶形和球冠形封头又统称为凸形封头。目前运用较为广泛的凸形封头是球形封头和椭圆形封头，球形封头因单位容积的表面积小，且在直径、壁厚和工作压力相同的条件下应力最小，两向薄膜应力相等，而且沿经线是均匀分布的。如果和壁厚相等的筒体连接，边缘附近的最大应力与薄膜应力并无明显不同等优点被广泛用于压力较高、直径较大的高压容器和特殊需要的场合；而椭圆形封头经线曲率变化平滑连续，故应力分布比较均匀，而椭圆形封头深度较半球形封头小得多，易于冲压成型，，是目前中、低压容器中应用较多的封头。由于压力容器在社会各行各业的生产、储存、运输等方面具有不可取代的地位，因此，为保证压力容器工作时的安全，对球形封头和椭圆形封头进行应力分析及测定课题的研究是十分必要的。目前应力分析方法有解析方法、数值方法、实验应力方法。随着科学技术的发展，新的实验应力测定及分析方法不断涌现，如电测法、光弹法、全息光弹法、全息干涉法、云纹法、散斑法等，目前应用最广泛的是电测法和光弹法。而本次研究将以解析法、电测法、有限元分析法分别进行应力分析，这种实验与理论相结合，用实验来验证理论分析的正确性，并借助计算机进行分析的方法，当前被广泛使用。本文研究的是压力容器的球形封头和椭圆形封头的应力测定及分析。该研究采用的是解析法、电测法、有限元分析法，首先在这些不同方法下分别获得各自的结果，并将所得的结果进行比较分析，指出两种形式的封头在实际应用中应注意的问题。最后将两种形式的封头的受力状况和结构特性进行比较，说明两种形式的封头在压力容器设计中被广泛使用的原因，即球形封头具有受力均匀、应力较小的优点，但深度大，整体冲压成型较为困难；椭圆形封头深度较浅，易于冲压成型，且受力状况仅次于球形封头，而比其他封头好。
[Abstract]:This paper mainly focuses on the research of pressure vessel, which is the key component of process equipment in traditional departments such as petroleum, chemical industry, light industry, transportation, food, pharmacy, metallurgy, textile and so on. The pressure vessel can be decomposed into the cylinder, the head, the support, the opening nozzle, the sealing device, the safety accessory, etc. The function of the head is to provide the required pressure space, according to the different geometry, the head can be divided into spherical, elliptical, butterfly, etc. The spherical, elliptical, butterfly and spherical crown heads are also known as convex heads. At present, the widely used convex head is spherical head and elliptical head. Because of the small surface area per unit volume, the spherical head has the smallest stress under the same diameter, wall thickness and working pressure, and the stress of the film is equal in both directions. And it is evenly distributed along the meridian. If the cylinder is connected with the wall thickness, the maximum stress near the edge and the film stress are not obviously different from each other. They are widely used in high pressure vessels with high pressure and large diameters and special needs. However, the curvature of the elliptical head is smooth and continuous, so the stress distribution is more uniform, and the depth of the elliptical head is much smaller than that of the hemispherical head, so it is easy to be punched. At present, the elliptical head is widely used in low pressure vessels. Since pressure vessels have an irreplaceable position in the production, storage and transportation of various sectors of society, in order to ensure the safety of pressure vessels, It is necessary to study the stress analysis and measurement of spherical head and elliptical head. At present, there are analytical method, numerical method and experimental stress method. With the development of science and technology, new experimental stress measurement and analysis methods have been emerging, such as electrometric method, photoelastic method, holographic interferometry, moire method, speckle method, etc. At present, the most widely used methods are electrometric method and photoelastic method. In this study, stress analysis will be carried out by analytical method, electric measurement method and finite element analysis method respectively. This kind of experiment is combined with theory to verify the correctness of the theoretical analysis, and the method of computer analysis is used to verify the correctness of the theoretical analysis. It is now widely used. The stress measurement and analysis of spherical and elliptical head of pressure vessel are studied in this paper. In this study, analytical method, electric measurement method and finite element analysis method are used. First of all, the respective results are obtained under these different methods, and the results obtained are compared and analyzed. The problems that should be paid attention to in practical application of two kinds of head are pointed out. Finally, by comparing the mechanical condition and structural characteristics of the two types of head, the reasons why the two types of head are widely used in the design of pressure vessel are explained, that is, the spherical head has the advantages of uniform force, small stress, but high depth. The whole stamping is difficult; The elliptical head is shallow in depth and easy to be punched, and its stress condition is second only to that of spherical head, which is better than that of other heads.
【学位授予单位】：西安工程大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TH49

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