Efficient analysis of welding thermal conduction using the Newton–Raphson method, implicit method, and their combination

Abstract

Finite element analysis is commonly used to investigate the thermal-mechanical phenomena during welding. To improve the computing efficiency of finite element analysis for welding thermal conduction, a novel Newton-Raphson method (NRM) without the computation of inverse matrix and a hybrid method combing the NRM and conventional implicit method (IMP) were developed. Comparison of computing time between the hybrid method implemented in an in-house software JWRIAN and the IMP used in a commercial software ABAQUS indicated that the computing speed of the former was about 4.5 times faster than that of the latter. Additionally, compared to the conventional IMP, the NRM exhibited higher computing efficiency in the analysis of transient thermal conduction during the welding heating process. Meanwhile, a combined hybrid method of the NRM and IMP was verified to be more efficient in analyzing the welding thermal conduction throughout the heating and cooling processes. Moreover, the thermal cycles computed by the hybrid method were consistent with those from experimental measurement, indicating the high accuracy of the hybrid method. Furthermore, the hybrid method was used to predict the temperature field of the corner boxing fillet joint welded by a low transformation temperature weld metal for generation of compressive residual stress.

Study on the temperature field distribution of the interface and process parameter optimization for material extrusion of PLA

“…Simultaneously, the sample mesh is divided into four layers with a total of 6400 regular hexahedral mesh cells. Every regular hexahedral mesh cell simulation on the grid unit to be set to an automatic time step with iterations of load steps following the Newton–Raphson method 30,31 . For each conventional hexahedral mesh cell SOLID70 as set, thermal conductivity with node‐8 and 1°C of freedom exists.…”

“…Every regular hexahedral mesh cell simulation on the grid unit to be set to an automatic time step with iterations of load steps following the Newton-Raphson method. 30,31 For each conventional hexahedral mesh cell SOLID70 as set, thermal conductivity with node-8 and 1 C of freedom exists. This allows the application of thermal analysis using mainly threedimensional steady-state temperature fields, together with the application of thermal analysis of temperature fields and the compensation of heat flow losses due to mass transfer in constant velocity fields.…”

Energy Optimization of the Continuous-Time Perfect Control Algorithm

“…Since the output behavior is guaranteed for all perfect control systems, the research challenge is now to find such nonunique inverses that will fulfill the imposed constrains. The obvious methods for searching the solution minimizing the attained goal function are the directional or gradient optimization approaches [25,26]. The other way of finding the optimal values for a given problem is the linear programming.…”

Investigation of the Residual Stress in a Multi-Pass T-Welded Joint Using Low Transformation Temperature Welding Wire

“…Accordingly, the residual stress distribution of the conventional T-welded joint was used for reference. In order to clarify the residual stress development in the course of the welding process, a finite-element analysis was performed using the in-house software JWRIAN [ 26 , 27 ]. Finally, the computed residual stresses were compared with those obtained from the experimental measurement.…”