【作者】 田锦邦；

【导师】 赵隆茂；

【作者基本信息】 太原理工大学 ， 固体力学， 2007， 博士

【摘要】 扁平绕带式压力容器是一种新型压力容器，已被广泛地应用于石油、化工和机械等工业领域。许多学者对扁平绕带式压力容器的静态力学性能问题进行了大量的实验研究和理论分析并取得了许多重要成果。在石油化工这一特殊行业中，这一类型的压力容器往往处于高温和高压下运行，在突发故障下可能引起的爆炸是不可避免的。其次，目前广泛使用的整体式高压容器，其难以克服的固有缺陷逐渐显露，扁平绕带式压力容器有望解决这类缺陷问题而被开发为新型高压容器。在公共安全方面，自美国发生9·11恐怖爆炸事件以来，国际上恐怖爆炸犯罪活动日益猖獗，为防止类似突发事件的发生，国家有关重要和安全部门以及人员高度集中或流动频繁的公共场所也需配置制造简便、体积较小和造价较低的爆炸容器以备紧急处理可疑爆炸物品，设计灵活、材料质量可靠和制造简便以及成本低的扁平绕带式压力容器具有被开发为此类爆炸容器的潜在前景。但是，对扁平绕带式压力容器在爆炸冲击载荷作用下动力特性问题研究的公开文献报道几乎没有。为了揭示扁平绕带式压力容器的动力特性，建立有关参量之间的关系，本文从实验研究和理论分析以及数值模拟等方面开展了一系列的工作，取得了以下重要结果：1)本文对钢带缠绕角度分别为10°、15°、20°的扁平绕带式压力容器和相同厚度相同长度的整体式圆柱形压力容器在其内腔中心位置安放TNT炸药进行了爆炸加载实验。实验研究发现，在大于100gTNT当量的爆炸下扁平绕带式压力容器产生明显的残余变形，主要集中在爆心附近且最大值在爆心横截面上。钢带缠绕角度为10°的扁平绕带式压力容器在500g TNT当量的爆炸冲击载荷作用下爆破，钢带缠绕角度为20°的扁平绕带式压力容器在450g TNT当量的爆炸冲击载荷作用下爆破，表明钢带缠绕倾角较小的扁平绕带式压力容器能够承受较大TNT当量的爆炸冲击载荷作用。钢带长度方向以拉应变为主、宽度方向以压应变为主，最大应变值出现在爆心横截面处，封头上的应变值是一个比爆心横截面处应变值小一个数量级的值。在相同TNT当量的爆炸冲击载荷作用下，扁平绕带式压力容器的塑性变形大于整体式圆柱形压力容器的塑性变形。扁平绕带式压力容器爆破前有明显的前兆，破裂位置在爆心附近，爆破后产生的碎片极少，对周围环境造成的危害程度较小。2)在实验研究的基础上，基于刚塑性理论，简化载荷形式，对扁平绕带式压力容器的动力响应问题进行了分析，给出了容器在矩形脉冲载荷和三角脉冲载荷作用下的塑性变形模态，推导出了容器的静态极限载荷、残余变形和响应时间的计算式。在矩形脉冲载荷作用下，扁平绕带式压力容器能够承受的静态极限载荷低于相同壁厚和相同长度的整体式圆柱形压力容器的静态极限载荷，钢带缠绕层数较多的扁平绕带式压力容器承受的静态极限载荷较大。在三角脉冲载荷作用下，扁平绕带式压力容器的塑性变形模态与实验得到的变形形状基本吻合，残余变形发生在爆心附近区域。扁平绕带式压力容器在较大三角脉冲载荷作用下的内壳和钢带缠绕层间分离，离内壳越远的钢带缠绕层其残余变形越大；绕带残余变形与实验值相比较偏大，这可能是由于忽略钢带缠绕预应力、层间摩擦力作用和材料应变率效应而造成的。在相同TNT当量的爆炸冲击载荷作用下，钢带缠绕倾角较小的扁平绕带式压力容器的塑性变形较小。3)采用双线性弹塑性本构模型，运用大型非线性有限元程序LS—DYNA对爆炸冲击载荷作用下的绕带式压力容器进行了数值模拟。有限元模型的几何尺寸和材料参数与实验容器的相同，通过Cowper-Symonds模型描述应变率效应。通过数值模拟研究发现，在大于100gTNT当量的爆炸冲击载荷作用下，扁平绕带式压力容器存在明显的残余变形，最大残余变形出现在爆心横截面处，残余变形由爆心处向远爆处方向迅速减小，与实验观察的现象相吻合。在相同TNT当量的爆炸冲击载荷作用下，钢带缠绕层的残余变形大于内壳的残余变形，越靠外的缠绕层，其残余变形越大，与理论分析结果一致。不考虑层间摩擦力作用的扁平绕带式压力容器内壳和最外层钢带的残余变形模拟值分别是考虑摩擦力作用的1.3倍和1.4倍左右，表明钢带层间摩擦力对扁平绕带式压力容器的塑性变形起着显著的抑制作用，说明在理论分析中没有考虑摩擦力作用的影响也是导致钢带缠绕层残余变形偏大的原因之一。在相同TNT当量的爆炸冲击载荷作用下，缠绕倾角越小的扁平绕带式压力容器，其相应的残余变形也越小，表明缠绕角度较小的扁平绕带式压力容器，其抗塑性变形能力较强。在100gTNT当量以上的爆炸冲击载荷作用下，扁平绕带式压力容器的残余变形大于整体式圆柱形压力容器的残余变形，这是由于钢带材质比整体式圆柱形压力容器材质较软、两种容器结构的能量吸收和耗散机理不同而造成的。扁平绕带式压力容器具有较强的塑性变形能力和较好的能量耗散机理，在发生爆裂时对周围环境造成的危害程度较小，可以开发为单次使用的反恐和公共安全领域运用的爆炸容器。本课题的研究在国内外尚属首次，研究结果对扁平绕带式压力容器抗爆设计和工程应用有重要的指导价值。更多还原

【Abstract】 A pressure vessel with flat-wound steel ribbons is a new kind of pressure vessel. Many such vessels are serving in industrial fields, such as petroleum, chemical industry, mechanical industry, etc. Many scholars have studied static mechanics characters of ribbon vessels in experimental and theoretic aspects and many important results are obtained. Especially, in the field of petroleum and chemical industry the vessels often work under high temperature and pressure circumstances. It is possible that the ribbon vessels are subjected to inner explosion loading in the process of utilizing practically because of bigger inner pressure. At present, disadvantages of the monobloc containment vessels used widely appear. Consequently, it is possible that some problems which are caused by the monobloc thick-walled containment vessel are solved through using the flat ribbon helically wound structure. Furthermore, in the public safety, because terroristic activities turn to more and more frequent since "9·11", some devices are needed to deal with explosive substances in public concourses, such as train stations, airports, post offices, wharfs and squares, etc. It has well foreground that the ribbon vessels with smaller volumes and low costs are developed to that type of vessels. But, there are few papers about dynamic characteristics of pressure vessels with flat-wound steel ribbon subjected to explosion loading. In order to reveal the dynamic characteristics of the pressure vessels, and to establish the quantitative relations between the concerned parameters, a series of studies have been made experimentally, theoretically and numerical simulation in present paper. The important results are summarized in the following several aspects.First, the vessels with 10°, 15°and 20°winding angle , respectively, and the monobloc cylindrical vessel are investigated experimentally. The experimental results show that the pressure vessels with flat-wound ribbons have residual deformation subjected to inner central blast loading when the quantity of explosive is more than 100g TNT. And the deformations are mainly concentrated near the center section of blasting. The vessel with 10°winding angle ruptures under 500g TNT. The vessel with 20°winding angle ruptures under 450g TNT, and the rupture locations of two vessels are near the central section of explosion. In the same time, the few broken fragments are produced. The ribbons are subjected to tensile stress in the length direction and compressive stress in the width direction. And the values of stress decrease gradually from the center of the vessels to the cover and flange. Experiment shows that the vessels subject to larger TNT explosion impact loading with the decreasing of the winding angle of the ribbons. The ribbon vessels compared with the monobloc vessels have better capacity of the plastic deformation, absorbing and releasing energy. In addition, both sizes of rupture and harm to environment are less than those of the monobloc.Secondly, based on the experimental results, the dynamic responses of the pressure vessels with flat-wound steel ribbons are studied through using rigid-plastic theory. The models of the plastic deformation of the vessels subjected to internal rectangular loading and triangular loading are given, respectively. The formulas of static limit loading, residual deformations and time of dynamic responses of the vessels are obtained. The limit loading of the vessels subjected to rectangular loading is smaller than that of the monobloc cylindrical vessel under the same conditions. The better the ribbon vessel capacity subjected to limit loading is, the more layers of the ribbons is. The deformation models of the vessels subjected to triangular loading are basically consistent with the ones that are obtained by the experiments. The residual deformations are concentrated on close center section of the vessels. The inner shell and the ribbons of the vessels are separated under the larger rectangular loading. The more the distance of the ribbons away from the inner shell is, the larger the residual deformations of them are. The theoretical values of the residual deformations of the ribbons are larger than the experimental ones because the pre-stresses of steel ribbons, the frictional force between the layers and the strain rate effect of the material are ignored possibly. The residual deformations of the vessels increase gradually with the winding angle increasing. The smaller the winding angle of the ribbons is, the higher the capacity of the deformation resistance of the vessel is.Finally, based on elastic-plastic theory, numerical simulation is achieved by non-linear finite element code LS-DYNA. The sizes and material parameters of FEM of vessels are identical to those of the experimental vessels. The strain rate effect of the materials is considered using Cowper-Symonds model. The numerical results show that the vessels have residual deformation when the quantity of explosive is larger than 100g TNT subjected to inner center explosion loading. The maximum deformation is on the centre cross section of explosion. The results simulated are consistent with those obtained by the experiment. The residual deformations of the ribbons is larger than those of the inner shell, and the larger the distance from the ribbon to the inner shell is, the larger the residual deformations of the ribbons are. The results are identical to the theoretical. The frictional forces between the ribbon layers improve the capacity of the deformation resistance remarkably. Therefore, the residual deformations of the ribbons theoretically are larger than those numerically. The vessel with smaller winding angle has the higher deformation resistance capacity. The residual deformations of the vessels are larger than those of the monobloc cylindrical vessels subjected to more than 100g TNT, it is caused by tensile strength of the materials made up the ribbons is smaller than that of the monobloc materials, and two kinds of vessels have different principle of absorbing and releasing energy.It is the first time that the study on dynamic characteristics of the pressure vessels with flat-wound steel ribbons in this paper is performed in the field. The work are extremely worthy for explosion resistance design and engineering application on the pressure vessels with flat-wound ribbons.更多还原