基于结构应力法的焊接构架应力状态研究
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摘要
采用结构应力法研究焊接构架焊接接头的应力状态.首先,结合结构应力法和BS EN15085-3:2007标准,提出焊接接头应力因数的计算方法,并归纳总结出确定焊接构架焊接接头应力状态等级的技术路线;其次,建立了包括焊缝在内的某焊接构架有限元模型,依据疲劳试验大纲中提供的疲劳载荷谱,分析了构架焊缝的结构应力分布特点,并利用结构应力法的98%可靠度-2σ的S-N曲线,对焊缝进行疲劳寿命预测,构架评估焊缝的总损伤均小于1,满足疲劳寿命设计要求;接着,基于构架评估焊缝的等效结构应力计算焊缝的应力因数,应力因数的最大值为0.79;最后,由应力因数的值,确定构架支撑座附近焊缝的应力状态等级为中.
According to the structural stress method and BS EN15085-3:2007,a calculation method of welding joint stress factor is proposed,and the technical route to determine welded joint stress state of the frame is summarized.A finite element model of a locomotive welded frame including welds is established,and the welds structural stress distribution is analyzed according to the fatigue load spectrum from the fatigue test outline.The welds fatigue life is predicted by using 98% reliability-2σ S-N curve of structural stress method.The weld total damage is less than 1,which meets the fatigue life design requirements,and the maximum value of weld stress factor is 0.79,calculated based on the welds equivalent structural stress.Finally,the welded frame stress state is determined by the welds stress factor,and the welds of the " middle" stress state are distributed near the supporting base of the frame.
According to the structural stress method and BS EN15085-3:2007,a calculation method of welding joint stress factor is proposed,and the technical route to determine welded joint stress state of the frame is summarized.A finite element model of a locomotive welded frame including welds is established,and the welds structural stress distribution is analyzed according to the fatigue load spectrum from the fatigue test outline.The welds fatigue life is predicted by using 98% reliability-2σ S-N curve of structural stress method.The weld total damage is less than 1,which meets the fatigue life design requirements,and the maximum value of weld stress factor is 0.79,calculated based on the welds equivalent structural stress.Finally,the welded frame stress state is determined by the welds stress factor,and the welds of the " middle" stress state are distributed near the supporting base of the frame.
引文
[1]李中彦. GE机车构架焊缝疲劳试验失效分析[J].机车车辆工艺,2009(3):20-21.
[2]赵峰强,张开林,刘斌.出口缅甸3B0机车焊接构架疲劳寿命预测[J].机车电传动,2017(1):51-54,60.
[3]卢耀辉.铁道客车转向架焊接构架疲劳可靠性研究[D].成都:西南交通大学,2011.
[4]BS EN 15085-3:2007.铁路应用-铁路车辆及其部件的焊接(第三部分:设计要求)[S].英国:英国标准学会,2007.
[5]兆文忠,李向伟,董平沙.焊接结构抗疲劳设计理论与方法[M].北京:机械工业出版社,2017.
[2]赵峰强,张开林,刘斌.出口缅甸3B0机车焊接构架疲劳寿命预测[J].机车电传动,2017(1):51-54,60.
[3]卢耀辉.铁道客车转向架焊接构架疲劳可靠性研究[D].成都:西南交通大学,2011.
[4]BS EN 15085-3:2007.铁路应用-铁路车辆及其部件的焊接(第三部分:设计要求)[S].英国:英国标准学会,2007.
[5]兆文忠,李向伟,董平沙.焊接结构抗疲劳设计理论与方法[M].北京:机械工业出版社,2017.