20000TEU集装箱船抗扭箱结构的焊接变形预控

抗扭箱作为20000TEU超大型集装箱船的关键结构,由于其组成的板材较厚且与集装箱直接接触,因此需严格控制该结构的面外焊接变形。采用基于固有变形理论的弹性有限元分析,预测抗扭箱的焊接变形,且与实际测量结果比较吻合；通过设计大厚板的非对称X型坡口来控制面外变形,结果表明：采用非对称设计的X型焊接坡口更有利于减小变形,仅需一次翻身、提高生产效率。在不考虑装配间隙时,基于高效的热-弹-塑性有限元计算归纳出超厚板(40mm~85mm)的最佳正反面坡口深度比；而考虑实际生产中的装配间隙时,最佳正反面坡口深度比与板材厚板呈非线性关系。最后将考虑装配间隙时,优化的非对称坡口焊接接头应用到抗扭箱结构中,面外焊接变形减小明显,有利于指导船厂的实际生产。

Prediction and Controlling Investigation of Welding Deformation on Critical Component of 20000TEU Container Ship (2): Torsion Box Structure

Torsion box structure as the key component for 20000TEU large container ship, is fabricated with thick plate and usually contact with container directly, therefore its welding distortion and precision fabrication are desired. Applying elastic FE analysis based on welding inherent deformation, welding distortion of torsion box structure was predicted and has a good agreement comparing with measurement. Mitigation of out-of-plane welding distortion was achieved by design of asymmetrical groove with X shape, which has the advantage to decrease welding distortion with one time turning over and high productivity. Without considering gap, optimal rate between top and back groove depth for thick plate (40mm-85mm) was obtained by means of effective thermal-elastic-plastic FE computation, and optimal rate between top and back groove depth has a non-linear relation to thickness when the gap was considered in actual manufacturing. Considering the effect of gap, optimal groove with asymmetrical X shape was practiced for welded joint of torsion box structure, and out-of-plane welding distortion was obviously mitigated.