Variation simulation and process diagnosis considering in-plane and out-of-plane welding distortion

Abstract

The shipbuilding industry has been working hard to solve the accuracy control problem for decades. Welding is mainly used to join two parts in shipyard. Welding generates localized heating within the parts that eventually causes inelastic distortion. Such variations caused by welding accumulate as many parts are joined together, which ultimately affect the final product. These variations are then subjected to correction, which takes a lot of effort, time and cost. As a study on the variation simulation, there has been a study on the compliant assembly. And the influence of the welding distortion that occurs at the joining process has been further studied. Welding distortion affects in-plane/out-of-plane variations. To date, studies related to variation simulation have focused mainly on out-of-plane variations. The variations generated in the in-plane direction is a problem directly related to the margin, which has a great effect on the productivity. Therefore, it is necessary to research the in-plane variation simulation model. In addition, since in-plane/out-of-plane variations affect each other, they must be considered together. This research aims to construct a variation simulation model for in-plane and out-of-plane variations. The geometric analysis was used to derive an equation that indicates the effect of out-of-plane variation on the in-plane variation. And each process was diagnosed using pattern analysis to see how each process contributed to the final assembly variation.