基于活络式方形压头的（舰）船用高强度钢冷压成形回弹关键技术研究

The new springback prediction and compensation control methods were proposed which can improve the forming efficiency and ensure the forming precision aiming at the springback technical problems in the forming process with adjustable square heads.. The plate elastic and plastic forming theory, finite element numerical simulation and experimental verification are combined to do further research on the high strength hull plate (medium thickness plate) springback behavior. Establish the response surface model based on radial basis function by uniform design test to determine the springback main influencing factors. The support vector machine technology is used to predict the springback.For single curvature hull, the curvature relationship formula between before and after springback is derived combining the theory of springback and numerical simulation. The discrete curvature compensation method is used to springback control. On the basis of single curvature hull, double curvature is discretd tiny quadrilateral single curvature differential element. The curve surface reconstruction algorithm based on the differential geometry is used to create a new envelope. Thus the springback can be control to some extent.. The springback prediction method and compensation control mode are innovated in the project .The springback number can be reduced or can reach forming once. Which improve the forming quality and efficiency have a great practical value.

针对活络式方形压头在冲压成形过程中存在的回弹技术难题，提出新的回弹预测和补偿控制方法，其目的在于提高成形效率和确保成形精度。. 本项目采用板材弹塑性成形理论、有限元数值模拟以及实验验证相结合的方法，深入研究高强度船体外板（中厚板）的回弹行为；通过均匀设计试验，建立基于径向基函数的响应面模型，确定影响回弹的主要因素，采用支持向量机技术预测回弹；对于单曲度板，结合回弹理论和数值模拟，推导回弹前后曲率关系计算公式，采用离散曲率补偿方法进行回弹控制，在此基础上将双曲度板离散为微小四边形单曲度微元，采用离散曲率进行回弹补偿控制，基于曲面曲线微分几何理论的曲面重构算法创建新的成形包络面，从而起到控制船体板回弹的作用。. 本项目在回弹预测和补偿控制方式上有所创新，通过本项目的研究能减少冷压成形次数或达到一次成形的目的，从而提高成形质量和效率，具有重大的实用价值。

船体外板的成形加工是造船生产的关键工序，是一直未能解决的瓶颈问题，回弹是影响成形精度的重要因素，根据非对压方形压头数控弯板机，建立一套适用于新型装置的回弹有限元数值模拟模型，并从材料、板厚、成形曲率、成形工艺以及成形方式等多方面对回弹影响因素进行分析，为回弹的补偿控制奠定基础；针对回弹样本数据较少的特点，采用支持向量机建立各种参数与回弹量间的预测模型，实验表明回弹预测结果符合精度要求，为回弹量的准确预测提出了一种新的解决思路。对于二维船用圆柱形板材，根据中厚板弯曲成形理论，建立了弹塑性总弯矩，推导了回弹前后的曲率变化。曲率修正系数由精确的数值模拟技术确定。对于变曲率船用钢板，根据其几何剖面线的曲率梯度将其离散为若干圆柱面。利用圆柱板回弹曲率修正补偿算法得到了补偿曲率阵列，并通过数值模拟验证了该算法的有效性。对于三维船体外板，采用几何补偿与神经网络相结合的方式进行回弹补偿控制研究。并对三维球面板材、帆形板和鞍形板材进行了数值模拟和实验验证。结果表明，该方法与预期结果非常接近，从而提高了成形的效率和精度。