Experimental Investigation And Numerical Simulation Of Welding Residual Stress In Wind-driven Generator Base

Along with the coal oil and other non-renewable traditional energy graduallylack, people pay more and more attention to other no pollution and recycling energy,the wind is one of them. In the12th Five-Year Plan, our country’s new energy strategyalso began to put developing wind power as a priority, and to promote theconstruction of the large wind power base, thus speeding up the development of windpower technology in China. The technical and quality requirements are very harsh.With the emergence of megawatt wind-driven generator and the quality of the weldaffects strength of components directly, the strength requirements of the wind-drivengenerator components is increased.Therefore, it is necessary to study the distributionand the size of welding residual stress on the weldment, and thereby takingappropriate measures to reduce and eliminate the welding residual stress.In order to know the concrete distribution of welding residual stresses inMegawatt wind turbine’s basis, we use the blind holes method to measure the threeplace welds of wind turbine generator, respectively is base cylinder body weld (weld1), the end plate joining together welding (weld2), end plate and cylinder body weld(weld3), we can get the every point’s strain value after patch and holing, and then wecan obtain these points’ stress value through the related calculation formula.Msc.Marc codes by finite element method were applied to simulate temperature andstress field of the base’s welded joints which were appeared on the screen by3Dreal-time dynamic numerical, the distribution of welding temperature field and theresidual stress is obtained and then the test results of welding residual stress arechecked by Blind-hole method. The welding residual stress in the condition of annealand non-anneal was comparatively analysed.We use the MSC.MARC FEM software’s welding analysis module in this paper,through the welding heat source selection of analysis, welding material in all themechanical properties of temperature analysis, solder paste heat transfer analysis,boundary condition analysis and convergence criteria set up etc, to base the weldingjoint way more than the finite element analysis, obtained the welding temperaturefield, welding deformation and the distribution of residual stress after welding state.Finally, the results show that the transverse and longitudinal residual stresses inthe area near the weld are comparatively larger, and the variation trend of thetransverse and longitudinal residual stresses in the area far away from the weld are nearly the same. It means that the FEM determination results coinciding with testresults are available for reference to the design of the Wind-driven generator weldingstructure.