摘要
氧气切割是船体结构临时开孔工艺中的首选方法,其产生的残余应力对后序封孔焊接与结构安全性均有重要影响.基于氧气切割原理,建立了预热火焰与铁氧反应生热的组合热源模型;基于热弹塑性有限元法,建立了氧气切割开孔过程的数值计算模型,并分析了切割温度场与残余应力场分布规律.通过氧气切割开孔实验进行结果验证,采用红外热像仪测量表面温度分布,应用压痕应变法测量残余应力,实验结果与计算结果基本吻合.研究结果表明:在割缝边缘存在超过材料屈服点的拉应力区,其宽度受切割速度、开孔尺寸与纵向约束等因素的影响.
Oxygen cutting is the principal method for temporary hatch opening of hull structure.Residual stresses induced by oxygen cutting have a large influence on subsequent sealing and structure safety.Based on the oxygen cutting theory,a heat source model was proposed with the combination of preheating flame and reaction heat between iron and oxygen,and a numerical model was presented to simulate the cutting process on the basis of thermal elastic-plastic FE analysis,involving the temperature and stress distributions.A series of oxygen cutting experiments were performed,in which an infrared radiation was used for surface temperature measurement and the residual stresses were measured by impact-indentation measurement.As a result,the calculation results are consistent with the experimental values.The research concludes that there is a region that the tensile stress values exceed the yield point of material along the kerf,and the width of this region is influenced by cutting velocity,opening dimension and longitudinal constraints.
出处
《大连理工大学学报》
EI
CAS
CSCD
北大核心
2012年第3期373-380,共8页
Journal of Dalian University of Technology
基金
国家自然科学基金资助项目(50805016)
辽宁省自然科学基金资助项目(20102028)
国家重点实验室专项经费资助课题(S08112)
关键词
结构开孔
氧气切割
数值模拟
温度场
残余应力
hatch opening
oxygen cutting
numerical simulation
temperature field
residual stress
