【作者】 舒斌；

【导师】 胡刚义；

【作者基本信息】 中国舰船研究院 ， 船舶与海洋结构物设计制造， 2011， 硕士

【摘要】 圆柱壳由于实际应用的要求常常需要开设各种大开孔,超出了常规设计方法的范围。由于几何尺寸、制造工艺和载荷形式的差别,理论计算圆柱壳大开孔结构的应力和应变比较困难,因此,对该结构进行系统、全面分析成为一个重要的课题。针对圆柱壳大开孔的补强计算方法、压力面积法、ASME法、有限元法以及潜艇结构设计计算方法等,分析了各种方法的异同,考证了各种方法的理论依据及由来,通过对实例大开孔结构进行计算比较,显示了其间的差异。本文针对均匀外压作用下圆柱壳大开孔,分别以围壁补强结构、围壁与加厚板组合补强结构为研究对象,采用三维有限元数值分析手段,得到了一些明确而有价值的结论。即随着开孔率的增加,开孔补强部位产生很高的应力。沿孔口边缘的弯曲应力值增加很快,并且超过了周向中面应力的10%,这时弯曲应力不应忽略不计,而应该进行单独校核。对外压作用下围壁补强结构进行三维有限元极限分析,获得结构关键部位的应变值和位移值,通过绘制载荷-位移曲线来研究开孔率和围壁与壳体厚度比对极限载荷的影响。通过研究发现:在相同加强条件下,极限载荷随着开孔率得增加而减小。孔口围壁加强对提高孔周局部极限载荷有明显效果。更多还原

【Abstract】 Due to the requirements of techniques and structure, Pressure Vessels often need to include large cutouts of various types which goes beyond the application of Design by Rules. But because of the changes of the geometry parameters, methods of manufacture and types of loads, it is difficult to calculate the stress and strain in the cylindrical shell structures with large cutouts in theory. Therefore, it is an important subject to analyze the structure systematically and roundly.Among the pressure area method, ASME method, finite element method and methods of design and calculation of submarine structure, the reinforcement calculation method of cylindrical shell with large cutouts was analyzed and compared. The similarities and difference were given. The principle of the calculation formulas of the methods was deduced. The difference was demonstrated by means of this four reinforcement design methods that a cylindrical shell with large cutout was calculated.The shows distribution of the area near by the junction of the coaming and the shell of large coaming-to-cylinder diameter ratio structure are studied. Two kinds of structures namely are studied and compared to each other. The finite element method and the strain-gauging method are applied in this work to investigate the distributions at reinforced area. Some new and valuable conclusions are achieved. The bigger the cutout rate of large cylindrical cutout is, the higher stress that the area of cutout produces. The bending stress at cutout edge is creasing very fast, in excess of 10% of the hoop membrane stress. Therefore, the bending stress should not be ignored but be checked solely.A study of limit loads was carried through three-dimensional nolinear finite element analysis on a coaming on cylinder shell structures subjected to uniform pressure. Models were studied by three-dimension nonlinear finite element method to gain the load-displacement and load-strain curves. By these curves, limit loads was carried out. The value of the limit load reduced with the cutout rate increase. The coaming has a favorable effect on the limit load.更多还原