机械密封焊接金属波纹管的疲劳寿命计算及分析
发布时间：2018-12-15 02:56
【摘要】：焊接金属波纹管机械密封,是用波纹管来替代密封中的弹簧和辅助密封圈。在旋转设备旋转时,机械密封中动环会产生轴向位移,而波纹管可以依靠本身的特性,来补偿及缓冲这一现象。对机械设备而言,机械密封的失效将影响其工作性能和使用寿命,而机械密封中焊接金属波纹管的失效在通常情况下为疲劳破坏,因此研讨焊接金属波纹管的疲劳寿命,具有重要意义。S型焊接金属波纹管机械密封,在安装时对中性良好,故不考虑其离心力,对波纹管受力分析。运用Solid Works和ANSYS Workbench等通用商业软件,对波纹管进行建模,网格划分以及静力学力分析,得到变形和应力的分布云图,并计算疲劳寿命。另外因波纹管处于高温工况,故对其进行热-结构耦合分析,探讨温度对疲劳寿命的影响。在此基础上,对S型焊接金属波纹管进行瞬态动应力分析,得到达到顶峰的最大应力值,并用公式估算其疲劳寿命,与热-结构耦合有限元结果相比较。最后,根据S型波纹管的几何形状,设计U型焊接金属波纹管,并在与S型相同工况下,求解U型波纹管的疲劳寿命,并与S型相比较。S型焊接金属波纹管,网格划分共生成557312个节点,87000个单元。静力学分析结果,最大变形为3.0586mm,位置在波纹管的游离端,小于其最小允许工作位移7.96mm;最大应力值为117.58MPa,位置在波纹管膜片的焊接处,小于材料316钢的许用应力206.7MPa;最小疲劳寿命为3.49年,满足工厂大检修的要求。热-结构耦合分析,得到最大变形为2.6728mm,小于其最小允许工作位移,其最大变形位置同样在波纹管的游离端;最大应力值为200.2MPa,在波纹管的固定端,是由于固定载荷引起的,在波纹管的焊接处,是危险部位,应力为121.11MPa;最小疲劳寿命为2.35年,比静力学分析下的疲劳寿命小,但同样满足工厂大检修的要求。在S型焊接金属波纹管的轴向瞬态动应力最大值为0.5764N时,有限元结果得到随时间变化的最大变形值和最大应力值。在t=0.021875s时,最大变形值和最大应力值达到顶峰,其中最大变形是2.6881mm,在波纹管的游离端;最大的应力值为103.45MPa,位于膜片的焊接处,都在允许范围之内。最大应力值与热-结构耦合同一位置应力结合,求得平均应力,代入道林损伤公式中,得到波纹管的使用寿命为2.59年,与有限元分析结果相差不大。U型焊接金属波纹管,网格划分共生成278062个节点,39432个单元。静力学分析结果,最大变形分别为0.17926mm,小于其允许工作位移,最大变形位置在波纹管的游离端;最大应力为198.47MPa,小于材料316钢的许用应力,位置在波纹管的波谷处;最小疲劳寿命为2.29年,满足工厂大检修的要求。热-结构耦合分析时,最大变形为0.16222mm,小于其允许工作位移,最大变形位置在波纹管的游离端;波纹管最大应力为567.76MPa,小于材料的3倍许用应力,在波纹管的固定端,是由于固定载荷引起的,在波纹管的波谷处,是危险部位,应力为166.08MPa;最小寿命为0.16年,不能满足工厂检修的要求。U型焊接金属波纹管与S型工况相同的情况下,进行瞬态动力学分析,得到随时间变化的最大变形值和最大应力值。同样在t=0.021875s时,最大变形值和最大应力值达到顶峰,其中最大变形是0.14934mm,在波纹管的游离端;最大的应力值为110.32MPa,同样位于波谷处,都在允许范围之内。最大应力值与热-结构耦合同一位置应力结合,求得平均应力,代入道林损伤公式中,得到波纹管的使用寿命为0.17年,与有限元分析结果相差不大。两种波形的波纹管,在不考虑温度的情况下,从疲劳寿命方面来说都能满足实际生产需要。但是在焊接金属波纹管机械密封中,波纹管不仅是连接元件,而且可以对动环产生的轴向位移进行缓冲和补偿。若U型波纹管弹性小的话,无法具有这一特性。而且U型焊接金属波纹管在高温工况下,其疲劳寿命比S型差很多。所以,对U型焊接金属波纹管来说,在旋转设备上,还是有一定的局限性,无法普遍的运用。通过以上的研究,为以后对焊接金属波纹管的设计研究提供参考,并对S型波纹管波形的优化提供新的方法。
[Abstract]:The mechanical seal of the welded metal bellows is to replace the spring and the auxiliary sealing ring in the seal with a bellows. When the rotating device is rotated, the dynamic ring in the mechanical seal will generate an axial displacement, and the bellows can rely on its own characteristics to compensate and buffer the phenomenon. In the case of mechanical equipment, the failure of mechanical seal will affect its working performance and service life, while the failure of welded metal bellows in mechanical seal is usually fatigue damage, so it is of great significance to study the fatigue life of welded metal bellows. The S-type welded metal bellows is mechanically sealed, and is neutral in installation. Therefore, the force analysis of the bellows is not considered due to the centrifugal force. By using the general commercial software such as Solid Works and ANSYS Workbench, the corrugated pipe is modeled, the mesh is divided and the static force is analyzed to obtain the distribution nephogram of deformation and stress, and the fatigue life is calculated. In addition, due to the high temperature working condition of the corrugated pipe, the thermal-structural coupling analysis is carried out to study the effect of temperature on the fatigue life. On this basis, the transient dynamic stress analysis of S-type welded metal bellows is carried out, the maximum stress value of the peak is obtained, and the fatigue life of the S-type welded metal bellows is estimated by the formula, and the fatigue life is compared with the heat-structure coupled finite element result. Finally, according to the geometry of the S-shaped bellows, the U-shaped welded metal bellows is designed and the fatigue life of the U-shaped bellows is solved under the same conditions as the S-shaped bellows and compared with the S-type. The S-type welding metal corrugated pipe and the grid are divided into a total of 557312 nodes and 87000 units. The results of the static analysis, the maximum deformation is 3.0586mm, the position is at the free end of the bellows, the minimum allowable working displacement is 7.96mm, the maximum stress value is 117.5. 58MPa, the position is at the welding position of the bellows diaphragm, the allowable stress of the material 316 steel is 207.7MPa, the minimum fatigue life is 3.49 years, to meet the requirements of the overhaul of the factory. the thermal-structural coupling analysis results in a maximum deformation of 2.6728mm, less than its minimum allowable working displacement, the maximum deformation position of which is also at the free end of the bellows, a maximum stress value of 200. 2mpa, at the fixed end of the bellows, due to a fixed load, at the welding of the bellows, It is the dangerous part, the stress is 121.11MPa, the minimum fatigue life is 2.35 years, and the fatigue life under the static analysis is small, but also meets the requirements of the overhaul of the factory. The maximum deformation value and the maximum stress value over time are obtained by the finite element method when the maximum axial transient stress of the S-type welded metal bellows is 0. 5764N. At t = 0. 021875s, the maximum deformation value and the maximum stress value reach the peak, where the maximum deformation is 2.6881mm, at the free end of the bellows; the maximum stress value is 103.45MPa, and the welding position of the diaphragm is within the allowable range. The maximum stress value is combined with the heat-structure coupled to the same position, and the average stress is obtained. In the formula of the damage to the tunnel, the service life of the bellows is 2. 59 years, and the difference between the maximum stress value and the finite element analysis is not large. The U-shaped welded metal corrugated pipe and the grid are divided into a total of 278062 nodes and 39432 units. The maximum deformation is 0.17926mm, less than the allowable working displacement, the maximum deformation is at the free end of the bellows, the maximum stress is 198.47MPa, the allowable stress of the 316 steel is less than that of the material 316, the position is at the wave trough of the corrugated pipe, the minimum fatigue life is 2.29 years, to meet the requirements of the overhaul of the factory. At the time of thermal-structural coupling analysis, the maximum deformation is 0.16222mm, less than the allowable working displacement, the maximum deformation position is at the free end of the bellows, the maximum stress of the bellows is 567.76MPa, the stress is less than 3 times of the material, the fixed end of the corrugated pipe is caused by the fixed load, At the trough of the corrugated pipe, it is a dangerous part, the stress is 166.08MPa, the minimum service life is 0. 16 years, and the requirement of factory overhaul cannot be met. When the U-shaped welded metal bellows is the same as the S-type working condition, the transient dynamic analysis is carried out to obtain the maximum deformation value and the maximum stress value which are changed over time. Also at t = 0. 021875s, the maximum deformation value and the maximum stress value reach the peak, where the maximum deformation is 0.14934mm, at the free end of the bellows; the maximum stress value is 1100.32MPa, also at the trough, all within the allowable range. The maximum stress value is combined with the heat-structure coupled with the same position, and the average stress is obtained. In the formula of the damage to the trace, the service life of the bellows is 0. 17 years, and the difference between the maximum stress value and the finite element analysis result is not large. The bellows of the two waveforms can meet the actual production needs in terms of fatigue life without taking into account the temperature. However, in the mechanical seal of welded metal bellows, the bellows is not only the connecting element, but also the axial displacement generated by the moving ring can be buffered and compensated. If the U-shaped bellows is small in elasticity, it is not possible to have this characteristic. and the fatigue life of the U-shaped welded metal corrugated pipe is much lower than that of the S-type under the high-temperature working condition. Therefore, for the U-shaped welded metal bellows, there are some limitations on the rotating equipment, which is not universally applicable. Through the above research, the author provides a reference for the design and research of the welding metal bellows, and provides a new method for the optimization of the S-shaped corrugated pipe.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG405
本文编号：2379837
[Abstract]:The mechanical seal of the welded metal bellows is to replace the spring and the auxiliary sealing ring in the seal with a bellows. When the rotating device is rotated, the dynamic ring in the mechanical seal will generate an axial displacement, and the bellows can rely on its own characteristics to compensate and buffer the phenomenon. In the case of mechanical equipment, the failure of mechanical seal will affect its working performance and service life, while the failure of welded metal bellows in mechanical seal is usually fatigue damage, so it is of great significance to study the fatigue life of welded metal bellows. The S-type welded metal bellows is mechanically sealed, and is neutral in installation. Therefore, the force analysis of the bellows is not considered due to the centrifugal force. By using the general commercial software such as Solid Works and ANSYS Workbench, the corrugated pipe is modeled, the mesh is divided and the static force is analyzed to obtain the distribution nephogram of deformation and stress, and the fatigue life is calculated. In addition, due to the high temperature working condition of the corrugated pipe, the thermal-structural coupling analysis is carried out to study the effect of temperature on the fatigue life. On this basis, the transient dynamic stress analysis of S-type welded metal bellows is carried out, the maximum stress value of the peak is obtained, and the fatigue life of the S-type welded metal bellows is estimated by the formula, and the fatigue life is compared with the heat-structure coupled finite element result. Finally, according to the geometry of the S-shaped bellows, the U-shaped welded metal bellows is designed and the fatigue life of the U-shaped bellows is solved under the same conditions as the S-shaped bellows and compared with the S-type. The S-type welding metal corrugated pipe and the grid are divided into a total of 557312 nodes and 87000 units. The results of the static analysis, the maximum deformation is 3.0586mm, the position is at the free end of the bellows, the minimum allowable working displacement is 7.96mm, the maximum stress value is 117.5. 58MPa, the position is at the welding position of the bellows diaphragm, the allowable stress of the material 316 steel is 207.7MPa, the minimum fatigue life is 3.49 years, to meet the requirements of the overhaul of the factory. the thermal-structural coupling analysis results in a maximum deformation of 2.6728mm, less than its minimum allowable working displacement, the maximum deformation position of which is also at the free end of the bellows, a maximum stress value of 200. 2mpa, at the fixed end of the bellows, due to a fixed load, at the welding of the bellows, It is the dangerous part, the stress is 121.11MPa, the minimum fatigue life is 2.35 years, and the fatigue life under the static analysis is small, but also meets the requirements of the overhaul of the factory. The maximum deformation value and the maximum stress value over time are obtained by the finite element method when the maximum axial transient stress of the S-type welded metal bellows is 0. 5764N. At t = 0. 021875s, the maximum deformation value and the maximum stress value reach the peak, where the maximum deformation is 2.6881mm, at the free end of the bellows; the maximum stress value is 103.45MPa, and the welding position of the diaphragm is within the allowable range. The maximum stress value is combined with the heat-structure coupled to the same position, and the average stress is obtained. In the formula of the damage to the tunnel, the service life of the bellows is 2. 59 years, and the difference between the maximum stress value and the finite element analysis is not large. The U-shaped welded metal corrugated pipe and the grid are divided into a total of 278062 nodes and 39432 units. The maximum deformation is 0.17926mm, less than the allowable working displacement, the maximum deformation is at the free end of the bellows, the maximum stress is 198.47MPa, the allowable stress of the 316 steel is less than that of the material 316, the position is at the wave trough of the corrugated pipe, the minimum fatigue life is 2.29 years, to meet the requirements of the overhaul of the factory. At the time of thermal-structural coupling analysis, the maximum deformation is 0.16222mm, less than the allowable working displacement, the maximum deformation position is at the free end of the bellows, the maximum stress of the bellows is 567.76MPa, the stress is less than 3 times of the material, the fixed end of the corrugated pipe is caused by the fixed load, At the trough of the corrugated pipe, it is a dangerous part, the stress is 166.08MPa, the minimum service life is 0. 16 years, and the requirement of factory overhaul cannot be met. When the U-shaped welded metal bellows is the same as the S-type working condition, the transient dynamic analysis is carried out to obtain the maximum deformation value and the maximum stress value which are changed over time. Also at t = 0. 021875s, the maximum deformation value and the maximum stress value reach the peak, where the maximum deformation is 0.14934mm, at the free end of the bellows; the maximum stress value is 1100.32MPa, also at the trough, all within the allowable range. The maximum stress value is combined with the heat-structure coupled with the same position, and the average stress is obtained. In the formula of the damage to the trace, the service life of the bellows is 0. 17 years, and the difference between the maximum stress value and the finite element analysis result is not large. The bellows of the two waveforms can meet the actual production needs in terms of fatigue life without taking into account the temperature. However, in the mechanical seal of welded metal bellows, the bellows is not only the connecting element, but also the axial displacement generated by the moving ring can be buffered and compensated. If the U-shaped bellows is small in elasticity, it is not possible to have this characteristic. and the fatigue life of the U-shaped welded metal corrugated pipe is much lower than that of the S-type under the high-temperature working condition. Therefore, for the U-shaped welded metal bellows, there are some limitations on the rotating equipment, which is not universally applicable. Through the above research, the author provides a reference for the design and research of the welding metal bellows, and provides a new method for the optimization of the S-shaped corrugated pipe.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG405
【参考文献】
相关期刊论文 前10条
1 刘宗虎;;波纹管机械密封的应用[J];山东工业技术;2015年11期
2 孙忠日;金昌寿;廉哲满;;基于ANSYS的S型波纹管的振动模态分析[J];机械工程师;2014年07期
3 孙泽刚;陈磊;;波纹管型机械密封的动压力分析及疲劳计算[J];润滑与密封;2014年05期
4 祝艳华;王鹏;;波纹管在控制阀上的应用介绍[J];中国石油和化工标准与质量;2014年09期
5 丁雪兴;张海舟;苏虹;赵芳;李驰;;螺旋槽干气密封气膜刚度测试与稳定性分析[J];振动与冲击;2013年12期
6 韩燕;王淮维;;温度对机械密封金属波纹管力学性能的影响[J];润滑与密封;2012年03期
7 周军;殷国富;陈珂;秦柱学;周永生;;高速卧式加工中心床身结构模态优化设计研究[J];机械制造;2011年03期
8 赵昕;;机械密封失效的原因及其改进策略[J];机械研究与应用;2011年01期
9 田坤;竺长安;;U形波纹管疲劳寿命研究[J];传感器与微系统;2011年02期
10 丁雪兴;富影杰;张静;吴振宁;任广江;;干气密封三种不同槽型线端面流场数值模拟[J];兰州理工大学学报;2010年03期
相关硕士学位论文 前6条
1 孙忠日;基于ANSYS的S型金属波纹管的有限元分析[D];延边大学;2014年
2 杨虎;机械密封用S型焊接金属波纹管组的刚度试验与理论模拟分析[D];新疆大学;2014年
3 陈俊成;深海用波纹管式压力平衡装置的研究[D];合肥工业大学;2014年
4 张静;干气密封焊接金属波纹管的动态性能分析及结构优化[D];兰州理工大学;2010年
5 王悦;机械密封焊接金属波纹管波片力学性能分析及结构优化[D];兰州理工大学;2008年
6 丁雪兴;金属膜片联轴器的膜片疲劳寿命计算及分析[D];兰州理工大学;2004年
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