【作者】 吴晓丹；

【导师】 郑津洋；

【作者基本信息】 浙江大学 ， 化工过程机械， 2007， 硕士

【摘要】 爆炸容器是一种潜在危险的限域装置，它能限制爆炸冲击波和产物的作用范围，对试验人员和设备实现有效的近距离保护，方便对爆炸和爆轰过程进行观察和测试，因此被广泛地应用于国防军事、爆炸加工、危险物质储运和科学研究等领域。随着爆炸容器的大型化，目前广泛使用的单层爆炸容器的固有缺点逐渐显露出来，如制造困难、成本高、厚钢板(锻件)质量不易保证等，难以满足爆炸容器大当量化的要求。因此研究新型结构爆炸容器来满足爆炸容器大当量化的要求具有十分重要的意义。本文以国家自然科学基金课题“密闭多层圆柱壳在内爆炸强动载荷下的动力响应和寿命研究”(项目编号：10372091)和“多层圆柱形爆炸容器设计方法研究”(项目编号：50675195)为依托，对离散多层爆炸容器在热冲击下的动态响应进行了研究。本文所作的主要工作和结论如下：(1)热冲击理论研究。通过将位移解分离为满足给定边界条件的准静态解和满足初始条件的动态解的方法求解内外层的径向位移，其中准静态解通过线性方法求得，热弹性动态解用Hankel积分变换求得。基于界面处径向位移连续条件，得到层间应力关于时间的第二类Volterra积分方程，再利用Hermit二次三项插值方法求解层间应力，从而得到内外层的位移和应力解。当不考虑热传导时，计算得到了离散多层爆炸容器在阶跃温度载荷作用下的动态响应。结果表明，钢带层缠绕倾角和内外层材料组合对离散多层爆炸容器的热应力有较大影响；为了降低整体的热应力峰值，内筒应选用弹性模量较小的材料。(2)不考虑热传导时的热冲击响应数值模拟。建立了缠绕倾角为零度和15度的离散多层圆筒的有限元模型，得到了在阶跃温度载荷作用下的瞬态热动应力。经与理论分析结果对比，发现有限元计算值能较好地预测离散多层圆筒的热应力响应，表明本文建立的有限元模型是合理的。(3)考虑热传导时的热冲击响应数值模拟。在内部发生爆炸后，容器壁厚方向上将产生瞬态温度梯度，运用LS-DYNA分析了容器壁厚方向上瞬态温度场的分布，并得到了瞬态热动应力。同与承受阶跃温度载荷作用下的离散多层圆筒的热动应力对比，发现在考虑热传导时，容器内部的瞬态热动应力峰值变低。数值计算结果还表明，瞬态热应力的最大值随着热膨胀系数的增大而增大，但随着比热容的增大而减小；而热传导系数的影响比较小。突加阶跃载荷是考虑热传导且热传导系数非常大时的一种特例。更多还原

【Abstract】 Explosion containment vessel is a device used for confining potential danger. It can restrict shock wave and production of explosion, effectively protect the test personnel and equipment near from the explosion, and facilitate the observation and testing of the explosion and detonation process. Therefore, it is widely used in national defense, fabrication using explosion process, storage and transportation of dangerous substances, scientific research and other fields. Because of the development of Military, fabrication and scientific research, there is a larger capacity trend of explosion containment vessels. With the capacity development of explosion containment vessels, the inherent shortcomings of the currently widely used single shell explosion containment vessels gradually reveal themselves. For instance, the manufacturing difficulties, high costs, and difficult quality assurance of the thick steel plate (Forge). Therefore, it is a very important to develop new type explosion containment vessel.Based on the National Natural Science Foundation "Analysis of Dynamic Elastic Response and Lifetime of Confined Multi-Layered Cylindrical Vessel under Strong Dynamic Load"(No.:10372091) and "Investigation on Method for Design of Multilayered Cylindrical Explosion Containment Vessels"(No.: 50675195), the dynamic response of the DMCECV subjected to the thermal impact is studied. The study of dynamic thermal-elastic response of the DMCECV under the thermal shock is divided into three parts:(1) Theoretical Analysis on thermal shock. The displacement solution of the dynamic equilibrium equations of both inner shell and outer ribbon layer of discrete multi-layered explosion containers can be decomposed into two parts, i.e., a thermo-elastic solution for inhomogeneous stress boundary conditions and a dynamic solution for homogeneous stress boundary conditions, under given initial conditions. The dynamic thermo-elastic solution is determined by linearity method and stress boundary conditions, and the dynamic solution is worked out by means of finite Hankel transform. By using radial displacement continuity, a second kind Volterraintegral equation is derived. Interpolation functions are used to approximate the unknown function in each time subinterval. The dynamic thermo-elastic solution caused by thermal shock on DMCECV is then determined. The thermo-elastic solution of a DMCECV is compared with the solution of a monobloc cylindrical shell, in order to verify the accuracy of theoretical solution.(2) Numerical simulation of the heat shock response without considering the thermal conductivity. DMCECV models of winding angles of 15 degrees and zero is constructed, and calculate the transient thermal stress under the step temperature load. Compare the results with the theoretical results, we can find that FEM can be used to calculate the transient thermal stress response of MDCEC, which shows that the constructed finite element model is reasonable.(3) Numerical simulation of the heat shock response considering the thermal conductivity. When internal explosion occurred in a vessel, there will be a transient temperature gradient along the wall thickness direction. LS-DYNA is used to calculate the transient temperature distribution along the thickness direction, and get the transient thermal stress. Comparing the results with the transient thermal stress of DMCECV under step temperature load, it is found that when the thermal conductivity is considered, the transient thermal stress peak becomes lower. The numerical results also show that the maximum transient thermal stresses increase with the increasing of heat exchange coefficient. But it will decrease with the increase of heat capacity. Thermal conductivity has little influence on maximum transient thermal stresses. Step temperature load is a special case of considering the heat conduction when the thermal conductivity is very large.更多还原