残余应力对GH3230层板焊缝热疲劳寿命影响规律研究OA北大核心CSTPCD

In order to investigate the influences of residual stress on the service life of weld seams of laminate cooling structures,first of all,finite element simulation and experimental verification were carried out on the laser welding processes of GH3230 laminate under conventional conditions.Then corresponding regulated approaches including pre-stretching and thermotensile et al.were simu-lated and analyzed.Afterwards,the evolutions of temperature and equivalent stress during service pe-riods with and without residual stress were studied respectively.The service life was later evaluated u-sing Coffin-Manson model modified by Morrow.The results demonstrate the thermal fatigue life caused by residual stress is significantly decreased.Furthermore,the stress amplitude and the mean stress while servicing,which decreasing 70％and 25％respectively,are effectively improved using regulating approaches mentioned above.Regulating welding residual stress is of vital importance for improving the thermal fatigue life of laminate structures.