The Welding Deformation Prediction And Secondary Development Of Bulk Cargo Section

Welding process occupies a large proportion in the modern shipbuilding technology.Welding deformation would be induced of section structure by plastic strain of seam when heatis concentrating on seam instead of whole plate in the process of welding. Welding deformationof section structure is the main factor that influences welding process, on one hand, it increasesthe compensation of steel material and related job, and further delays the shipbuilding cycle; onthe other hand, it increases lots of labor and material supplies. Therefore, the accurateprediction of the welding deformation of hull section is of a vital significance in improving theefficiency of welding, shorting construction cycle and reducing the manufacturing cost ofshipbuilding.Based on the theory of the inherent strain equivalent load method, the welding deformationprediction of section in bulk cargo area has been carried out by employing finite elementmethod. Further, the secondary development has been applied to encapsulate the predictionmethod. Taking butt seam, angle seam, small seam component and the double bottom blockstructure as example, respectively, the analysis model have been built by the finite elementsoftware. According to the generating mechanism of inherent strain and the weldingtemperature theory, the area of the inherent strain is assured, then the longitudinal andtransverse modulus of elasticity reinforcement of plate welding butt and reinforcement of weldvoid are calculated depended on Hooke’s law. Substituting those obtained results into thesimplified formula of inherent strain, then integrating inherent strain in welding section, theequivalent loads of welding inherent strain are obtained. By calculating equivalent loadsacting on region of inherent strain, welding deformations of section structures have beencalculated through one elastic finite element analysis. The comparison of section structurebetween predicted welding deformation and actual data from shipyard prediction shows agood agreement, which verifies the employed equivalent inherent strain method. Combiningwith interactive interface technology of VB and ANSYS, the encapsulation of employedwelding deformation prediction method has been carried out. Transforming program isdeveloped to simplify and visualize the complicated process of applied equivalent inherentstrain method. In the designed interface, the employed welding deformation predictionprogram can be carried out in background by inputting the geometry parameters of sectionstructure, assigning the grid size and load solution set. The developed interface makes the welding deformation prediction of section based on equivalent load method more simple andconvenient.