【作者】 周波；

【导师】 刘玉君； 纪卓尚；

【作者基本信息】 大连理工大学 ， 船舶与海洋结构物设计制造， 2009， 博士

【摘要】 提高船舶质量,降低生产成本,缩短施工时间,是船舶行业经济发展到一定阶段的必然结果和要求。改进造船工艺水平是提高船舶质量,降低生产成本的主要手段。船舶建造过程应力和变形控制研究是改进造船工艺水平的基础,深入研究船舶制造中的应力和变形问题,从力学角度分析造船工艺的科学性和合理性,发现问题,找出改进措施,进而为施工工艺改进提供理论基础和技术支持。本论文主要对如下三项船舶制造相关工艺技术进行研究:(1)船体外板自重成型预报研究开展了船体外板自重成型预报系统研究。在考虑大应变效应基础上,采用有限元方法分析薄板大挠度弯曲,经实船板自重成型实验验证,所建立的船体板有限元模型准确可靠。应用有限元法进行船体板自重成型数值实验,确定钢板几何参数与钢板成型间的函数关系,建立船体外板自重成型的数学模型。基于以上算法,结合加工精度要求,开发了自重成型预报系统。该预报系统已用于船厂生产实践,产生良好效益。(2)上层建筑整体吊装工艺技术研究首先,进行了上层建筑整体吊装工艺研究。以1.26万吨油船上层建筑为例,进行上层建筑整体吊装强度分析。在此基础上,进行吊装辅助工装设备—吊架的发明设计工作,并根据吊架设计整吊工艺方案,计算验证方案的可靠性,对上层建筑整体吊装用吊架发明进行详细说明。其次,开展了吊环强度校核方法研究。分析吊环孔分布力情况,并结合曲梁理论推导了新的吊环强度计算公式。通过与传统强度校核公式和有限元计算结果对比可以看出,新公式计算结果比传统强度校核公式更加接近实际情况。采用新的吊环强度计算公式可显著提高吊环结构设计的可靠性。(3)船体结构修造开口工艺技术研究采用热弹塑性理论,应用有限元方法,建立切割分析数值模型。进行切割实验研究,采用红外测温技术测量切割过程温度场,采用压痕应变法测量钢板切割残余应力。将实验数据和数值模拟结果对比,可以看出二者基本一致,验证了切割数值模型的可靠性。在此基础上,对平板切割开口进行数值实验,分析了割缝长度、钢板边界约束条件、钢板尺寸、开口形式和开口位置的影响规律。应用所建立的切割模型,对船体结构开口进行数值模拟,分析切割开口工艺的安全性。更多还原

【Abstract】 Improving manufacturing accuracy, reduce the production costs and increasing labor productivity are inevitable results and requests of the development of shipbuilding. It is an important method for advancing shipbuilding quality to improve shipbuilding processes. Research on technic of shipbuilding processes is the foundation of improve shipbuilding processes. Therefore, research on technic of shipbuilding processes is essential. In this study, researches on three shipbuilding key processes are performed.(1) Research on Dead Load Forming of Hull Steel PlatesThe relatively large deflections of sheet are described and the models of finite element method are built and checked up by experimental measure of dead load forming. The database of the calculations for dead load forming of hull steel plates is established. Data of effective parameters are measured, and the effect principles of the primary parameters such as length, width, thickness, and radius are qualitatively analyzed. With curve estimate and multi-variable stepwise regression analysis methods, mathematical models for the dead load forming of hull steel plates based on the primary parameters such as length, width, thickness are presented.. Based on above algorithm, and combined with shipyard production condition, a forecasting system is developed for the dead load forming of hull saddle shaped steel plates. Factual plate tests in shipyard production show a forming precision of this system.(2) Research on technic of ship superstructure’s integral assemblyFirst, ship superstructure’s integral assembly (SSIA) is an advance process, but still a hard nut, in ship construction. In this study, taken 12,600 tons oil tanker as an example, the arrangement of lifting padeyes in SSIA is analyzed with the theory of structure strength and finite element method (FEM). Base on the strength analysis, a new hanger of SSIA is invented and the credibility of design is verified. Some basic regulations of SSIA are found.Secondly, strength Analysis methods of Lifting Padeye are developed. In the paper, the external loads on the padeyes are analyzed and a robust stress check formula is derived using curved beam theory. The results of finite element method (FEM) and the solutions of traditional check formula and new check formula are compared. It is shown that the new expressions account for a better representation of the real stress value and distribution. By applying the strength check formula presented in the paper, the safe reliability of structure design can be improved significantly. (3) Research on technic of cutting hatch openings in ship structureNumerical analysis of cutting in ship structure is performed. This study applies thermal elastoplastic analysis, using finite element techniques, to build a model for the temperature distribution during cutting and stress distribution in the workpiece. A non-contact temperature method—Infrared Radiation (IR) is used for surface temperature measurement. The residual stresses at the surface of the workpiece were measured by impact-indentation measurement. The results of finite element analysis were compared with experimental results to confirm the accuracy of the method. Numerical experiment of cutting hatch in flat plate is put up, and the effect principles of the primary parameters such as length of cutting line, bound condition, size of steel plate, the form of hatch, position of hatch are analyzed. On this basis, numerical analysis of cutting in ship structure is performed and the deformation and stress are analyzed.更多还原