惯性释放法在大型复杂结构焊接变形预测中的应用

在进行大型结构焊接变形有限元分析时，为了固定整体结构刚体位移必须施加不少于6个自由度的约束，但对于自由状态下的结构而言，如何施加这6个最少约束是非常的困难，长期以来是困扰研究人员的难题，也是焊接结构有限元分析在工业现场应用的一个瓶颈。所谓惯性释放法就是可以在不加约束的情况下模拟自由结构的变形。该文将在航海航空领域得到广泛应用的惯性释放法引入大型焊接结构变形分析，解决了自由状态下结构必须施加约束的问题。首先以典型的对接接头为例，比较了两种不同的约束方法之间的差别。然后通过一个典型的船体焊接变形预测的实例，验证了惯性释放法在大型结构中应用的可行性，为焊接结构变形分析在工业生产中广泛应用提供了一个有效的方法。

Application of Inertia Relief in the Prediction of Welding Deformation for Large Complex Structures

Rigid-body motion boundary condition during computational welding mechanics, of which at least 6 degrees of freedom of welded structure will be fixed, is widely used to predict the welding distortion. However, because of the large scale and complexity of some structures, it is not advisable to consider the constraint for the unsupported welded structure during the computation. In this study, inertia relief method, the inertia force of the unconstrained structure is relieved to balance the exter-nal force, is proposed to investigate the welding deformation. Two methods are compared by predict-ing the welding deformation of a butt welded joint. Then, a hull block is taken as an example, simu-lations based on inherent deformation are conducted considering the inertia relief and rigid-body motion boundary conditions. By comparing the deformation of measured point, the computational re-sults by using inertia relief are the most approximate to measurement results compared to other cas-es, and it is more convenient to set the boundary condition using the proposed method which pro-vides an effective choice for the industrial application of welding structure deformation prediction.