全焊接球阀焊接过程模拟及应力强度评定
发布时间：2018-09-11 07:04
【摘要】：全焊接球阀应用于大型石油天然气管线,其质量直接关系到国家能源运输安全。由于应用条件限制,焊后不能进行热处理,因此对焊缝有较高的强度要求。同时,长输管线恶劣的应用环境对管线球阀的抗外载荷能力提出了严格的技术要求。合理控制焊接残余应力的分布以及确定管线球阀的极限承载能力对优化工艺参数和节省材料具有重要的意义。 在弹塑性理论的基础上,在ABAQUS软件中建立了全焊接球阀的有限元模型,根据实测残余应力值,使用生死单元技术预制了多层焊下全焊接球阀的残余应力。在此基础上,通过对管线球阀施加内压和弯曲载荷,得到了管线失效时球阀的应力分布,结果表明,材料发生失效的位置出现在阀门和管道相接处。然后,根据ASMEⅧ-2中的相关规定,在球阀关键位置绘制等效应力线,对应力进行分类和强度评定,论证了全焊接球阀的应力在管道失效时处于安全水平。 为进一步研究阀门的承载能力,通过改变载荷条件,确定了现有壁厚下管线球阀所能承受的极限内压。在进一步的阀体壁厚校核中发现,实际阀门的厚度远远大于压力设计厚度,因此,通过对不同厚度的阀门进行试算,最终确定了工作内压下的最小阀门壁厚。
[Abstract]:The quality of fully welded ball valve used in large oil and gas pipeline is directly related to the national energy transportation safety. Due to the limitation of application condition, heat treatment can not be carried out after welding, so the strength of weld seam is very high. At the same time, the harsh application environment of long distance pipeline puts forward strict technical requirements for the ability of pipeline ball valve to resist external load. It is important to control the distribution of welding residual stress and determine the ultimate bearing capacity of pipeline ball valve for optimizing process parameters and saving materials. On the basis of elastic-plastic theory, the finite element model of fully welded ball valve is established in ABAQUS software. According to the measured residual stress value, the residual stress of fully welded ball valve under multilayer welding is prefabricated by using the birth and death element technique. On this basis, by applying internal pressure and bending load to the pipeline ball valve, the stress distribution of the ball valve is obtained when the pipeline fails. The results show that the material failure occurs at the junction of the valve and the pipeline. Then, according to the relevant provisions of ASME 鈪，
本文编号：2235959
[Abstract]:The quality of fully welded ball valve used in large oil and gas pipeline is directly related to the national energy transportation safety. Due to the limitation of application condition, heat treatment can not be carried out after welding, so the strength of weld seam is very high. At the same time, the harsh application environment of long distance pipeline puts forward strict technical requirements for the ability of pipeline ball valve to resist external load. It is important to control the distribution of welding residual stress and determine the ultimate bearing capacity of pipeline ball valve for optimizing process parameters and saving materials. On the basis of elastic-plastic theory, the finite element model of fully welded ball valve is established in ABAQUS software. According to the measured residual stress value, the residual stress of fully welded ball valve under multilayer welding is prefabricated by using the birth and death element technique. On this basis, by applying internal pressure and bending load to the pipeline ball valve, the stress distribution of the ball valve is obtained when the pipeline fails. The results show that the material failure occurs at the junction of the valve and the pipeline. Then, according to the relevant provisions of ASME 鈪，
本文编号：2235959
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