船体外板曲面热成型加工自动化关键技术研究

发布时间：2018-06-18 02:20

本文选题：高强度钢 + 感应加热　；参考：《江苏科技大学》2014年硕士论文

【摘要】：热应力成型是加工板料的一种重要成型方法。目前高强度钢已广泛应用于船舶生产中但尚未有成熟的高强度钢热应力成型技术。没有成熟的工艺就无法完成大量钢板的加工任务，这项工艺已逐渐成为整个造船生产流程的瓶颈。因此，基于船体外板曲面热成型加工自动化关键技术研究有着非常现实的工程应用背景与意义。就是在这样一个工程背景下，展开对高频感应弯板成型的研究。高频感应热应力成型是一个局部快速加热到高温，并随后快速冷却的过程。整个钢板的温度随时间和空间急剧变化，材料的物理性能参数也随温度剧烈变化。因此，高频感应温度场的分析属于典型的非线性瞬态热传导问题。因为高频感应温度场分布十分不均匀，在感应加热过程中和冷却后将产生相当大的应力和变形。高频感应应力和变形的计算中既有大应变、大变形等几何非线性问题又有弹塑性变形等材料非线性问题。为辅助课题的开展，在前人研究成果的基础上，通过理论分析和有限元数值模拟相结合的方法，模拟出了高频感应弯板成型过程。研究的主要内容包括：（1）在计算过程中材料性能随温度变化而变化，属于材料非线性问题，提出了基于Jmatpro的高强度钢热物理性能研究。（2）在45号钢弯板成型有限元模型的基础上进行修改和优化，结合AH32号钢的热物理性能参数，得到了适用于AH32号钢的磁-热-结构多场耦合的有限元模型并验证了其模型的有效性。（3）基于AH32号钢的磁-热-结构多场耦合的有限元模型，在给定不同工艺参数（加热时间、板厚、电流强度、频率大小、冷却方式）的前提下，用此有限元模型预测AH32号钢弯曲变形结果，分析结果对现实的生产工艺有一定的指导价值。（4）在曲面测量技术中，研究了基于三角网格模型的自适应测点生成算法，，对测量路径优化问题进行了合理的描述。最后结合相应的理论方法，基于matlab对离散点进行逆向拟合得到相应的弯板曲面模型。通过研究和算例验证，得到了可行的AH32号钢高频感应弯板温度场、应力场的模拟分析方法，为复杂高强度钢热应力成型结构进行高频感应弯板温度场、应力的分析提供了理论依据和指导，促进了有限元分析技术在热应力成型分析以及工程中的应用。
[Abstract]:Thermal stress forming is an important forming method for processing board. High strength steel is now widely used in shipbuilding but has not yet mature high strength steel thermal stress forming technology. Without mature technology, the processing task of large number of steel plates can not be completed. This process has gradually become the bottleneck of the whole shipbuilding process. The research on the key technology of automatic thermal processing for sheet metal surface has a very practical engineering application background and significance.
The high frequency induction thermal stress forming is a process of rapid heating to high temperature and then rapidly cooling. The temperature of the whole steel plate varies rapidly with time and space, and the physical properties of the material vary sharply with the temperature. Therefore, the high frequency induction is induced by high frequency induction. The analysis of temperature field is a typical nonlinear transient heat conduction problem. Because the distribution of high frequency induction temperature field is very uneven, it will produce considerable stress and deformation in the induction heating process and after cooling. The calculation of high frequency induction stress and deformation has both large strain, large deformation and other geometric nonlinear problems, such as elastoplastic deformation and so on. On the basis of the research achievements of predecessors, through the combination of theoretical analysis and finite element numerical simulation, the forming process of high frequency induction bending plate is simulated.
The main contents of the study include: (1) the material performance changes with the temperature change during the calculation, which belongs to the material nonlinear problem, and puts forward the research on the thermophysical properties of high strength steel based on Jmatpro. (2) on the basis of the finite element model of the 45 steel bending plate, the thermal physical property parameters of AH32 steel are obtained. The magneto thermal structural multi field coupling finite element model for AH32 steel is applied and the validity of the model is verified. (3) a finite element model of magnetic thermal structure multi field coupling based on AH32 steel is used to predict AH with this finite element model on the premise of given different process parameters (heating time, plate thickness, current intensity, low frequency and cooling mode). The result of bending deformation of No. 32 steel has a certain guiding value for the actual production process. (4) in the surface measurement technology, the adaptive point generation algorithm based on triangular mesh model is studied, and the problem of measurement path optimization is reasonably described. Finally, based on the corresponding theoretical method, the inverse of the discrete point is carried out based on MATLAB. The corresponding curved plate surface model is obtained by fitting.
Through the study and calculation example, the temperature field of the high frequency induction bending plate of AH32 steel and the simulated analysis method of stress field are obtained. It provides the theoretical basis and guidance for the analysis of the stress of the complex high strength steel thermal stress forming structure, and the analysis of the finite element analysis technology in the thermal stress forming analysis and the analysis of the thermal stress. Application in engineering.
【学位授予单位】：江苏科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U671

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