船体曲率板感应加热成形工艺研究

目的]在船舶建造过程中,板材的弯曲成形工艺不仅影响建造成本及周期,而且其成形精度也会影响船舶的水动力性能及其运营成本。方法]针对船体板材双曲率成形效率低且精度差等问题,首先以感应加热作为热源,实现热弯成形,得到典型的帆形曲率板;然后通过高效的热?弹?塑性有限元(TEP FE)计算及基于弯曲力矩的弹性有限元计算,再现板材双曲率热弯成形的力学响应;同时,研究感应加热过程工艺参数影响板材弯曲成形的力学机理,提出线性逼近迭代二分法,实现板材热弯成形中加热位置和热源移动速度等工艺规划,并进行板材热弯成形过程及参数的有限元计算验证。结果]结果显示,采用基于规划的工艺参数计算分析所得面外弯曲变形与目标曲率板的弯曲形状相当吻合。结论]研究结果验证了线性逼近迭代二分法在实际工程应用中的可行性和准确性,并为曲率板成形工艺的优化提供了新的解决方案。

An investigation of the induction heating forming process of hull curved plate

Objectives]A plate forming technique during ship construction will not only influence the cost and scheduling of fabrication,but also the accuracy of its formation will influence hydrodynamic performance and operating costs.Methods]In order to cope with such problems as low efficiency and poor accuracy during double-curvature plate forming,induction heating was used to provide an advanced heating source for plate bending with a typical sail shape.By using advanced thermal elastic plastic finite element(TEP FE)analysis and elastic FE analysis on the moment of bending,the mechanical response during plate bending was then represented,and the computed results strongly correlate with the measurements.Moreover,the plate forming process parameters'mechanism of influence was also clarified,and a method using linear approximation with an iterative bisection was proposed to obtain the line heating position and moving speed of the induction heating coil during induction heated plate formation,while the planned processing parameters were also validated and confirmed using a numerical analysis.Results]The computed out-of-plane bending deformation within the planned parameters well agrees with the target bending deformation.Conclusions]The engineering application of the plate bending method using linear approximation with iterative bisection has also been confirmed,which provides new solution for process parameter optimization during plate bending with induction heating.