Parametric Welding Deformations Prediction Of Ship Hull Blocks

Welding deformations of ship hull blocks cause great difficulty during the rest weld and assembly of the structure. Thus, precisely predicting the deformations of large ship blocks is worthwhile in engineering practice. The equivalent load method based on the inherent strain is a fast developed prediction method these years, but as for large structures, it takes a long period to calculate the deformation. Applying parametric technology to prediction of welding deformation will largely increase the analysis efficiency, and this research subject will have a deep and long-term meaning.The equivalent load method based on the inherent strain is studied to analyze the welding deformations of real ship sections. The details are as follows:1. The rules of welding temperature field dependent on time and space are analyzed by simulating the three-dimensional transient temperature for bead-on-plate welding and fillet welding, and the experienced highest temperatures of the transverse section are obtained; the parametric program is composed, and by rerunning it for several times, the effects of the three parameters on the temperature are studied, and the quantitative conclusions are obtained.2. Degree of constraint distributions based on different welding sequences are obtained by combining experimental data and twice equivalent load FEA.3. Inherent strain distribution is calculated through the highest temperatures and degrees of constraint, according to its origin principle, and the equivalent load is obtained by integral which improves the prediction precision.4. The reliability of the equivalent load method based on inherent strain is demonstrated by comparing the calculated results to the experimental data of a stiffened panel.5. Welding deformations of the ship section are obtained which supply reference to practice, and accumulate experiences in large structures research.6. Higher efficiency is achieved by using the APDL programming language during most of the analysis process which takes a big step towards welding deformation prediction of ship sections by a developed method combining with the functions of ANSYS.