Research On The Algorithm Of Heating Line Arrangement For Line Heating

The hot water bending process is the main method for the forming of hull complex curved surface.For a long time,shipyard has been relying on experienced workers to complete the process,which has the disadvantages of poor forming quality and large quality fluctuation.One of the main tasks of the process automation of the water fire bending is to realize the automatic prediction of the process parameters.Therefore,in recent years,a large number of researchers have carried out the research work of the process parameter prediction.The traditional research idea is to expand the complex surface to obtain the local deformation,and then according to the method of combining experiment and numerical simulation to study the relationship between process parameters and local shrinkage and establish the corresponding mathematical model,so as to arrange the heating wire.This method only considers the local deformation and ignores the whole deformation,so the calculation error is large.In this paper,based on the mathematical study of the hull surface,the optimal layout of the heating line is carried out on the premise of obtaining the local shrinkage of the complex curved surface.The optimal placement algorithm of heating wire considers the whole shrinkage deformation on the basis of local shrinkage deformation,and considers the whole shrinkage deformation in the form of local shrinkage distribution.Combined with the actual characteristics of the ship’s complex curved surface,the optimization objective and constraint conditions of the algorithm are set to optimize the layout of the heating line.The calculation results show that the shrinkage distribution and centroid position obtained by the algorithm are consistent with the theoretical shrinkage distribution after the design surface is expanded,which improves the processing accuracy of the hot water bending.Based on VB language,a computer-aided process planning information system for water and fire bending is developed.The core algorithm of the system is the algorithm of surface unfolding and the algorithm of heating line arrangement.The database of plate parts is established and the common AutoCAD interface of ship design and construction is set up.The data points in the calculation process are modeled in three dimensions by using OpenGL graphic library to realize the dynamic visualization of the model.The system can The position,length,moving speed of heat source and heating time of the heating line are output and encapsulated into text files and graphic files for reference of the staff.