摘要
针对大椭球比扁平复合材料气瓶的疲劳失效问题,以TA1钛合金为超薄壁内衬(0.8 mm)、碳纤维/环氧树脂为复合材料层、椭球比为2.3∶1的扁平复合材料气瓶为研究对象,分析影响气瓶疲劳失效的主要因素。结合寿命预测模型,确定了气瓶的疲劳寿命、疲劳失效位置及其变化规律,并开展试验验证。结果表明:疲劳寿命预测结果与试验结果吻合率达93%;采用实体单元SOLID185与壳单元SHELL181组合建模方法,可有效模拟多层铺设结构的疲劳寿命;大变形扁平气瓶在升/泄压过程中,内衬弹性变形随压力降低可回弹,其永久塑性变形和材料断裂应变直接影响疲劳寿命;选择最佳自紧压力有助于扩大气瓶弹性工作范围,当自紧压力从18 MPa增加至24 MPa时,疲劳寿命由99次提高至304次,提升幅度达207%。研究成果可为大椭球比扁平复合材料气瓶的研制提供参考。
To address the fatigue failure issue of flat composite cylinders with high ellipticity ratio,this study analyzed the main factors influencing cylinder fatigue failure using a flat composite cylinder with TA1 titanium alloy as ultra⁃thin wall liner(0.8 mm),carbon fiber/epoxy as composite layer,and ellipticity ratio of 2.3∶1.Combining a life prediction model,the fatigue life,failure locations,and their evolution patterns were determined,and experimental validation was conducted.Results show that the fatigue life prediction accuracy reached 93%compared to experimental data.The combined modeling approach using SOLID185 solid elements and SHELL181 shell elements effectively simulated fatigue life of multi⁃layer structures.During pressurization/depressurization cycles,the liner's elastic deformation rebounds upon pressure reduction,while permanent plastic deformation and material fracture strain directly affect fatigue life.Selecting optimal autofrettage pressure expands the elastic working range;when autofrettage pressure increased from 18 MPa to 24 MPa,fatigue life rose from 99 cycles to 304 cycles,a 207%improvement.These findings provide references for developing high⁃ellipticity⁃ratio flat composite cylinders.
作者
李玉峰
马天驹
LI Yufeng;MA Tianju(Lanzhou Institute of Aerospace Technology and Physics,Lanzhou 730000,China)
出处
《压力容器》
北大核心
2025年第3期44-53,共10页
Pressure Vessel Technology
关键词
复合材料气瓶
疲劳寿命
椭球比
扁平异形
composite cylinder
fatigue life
ellipticity ratio
flat⁃shaped
