长管拖车天然气瓶强度与疲劳寿命分析

发布时间：2018-02-12 15:54

本文关键词： 长管拖车天然气瓶疲劳寿命有限元分析气瓶　出处：《河北科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着世界能源消耗的急剧增加和环境问题的日益严峻,天然气在总能源消耗中所占的比例越来越大。天然气长距离运输以管道为主,但在天然气的短距离运输中,铺设管道投资巨大,更适合采用车辆运输。长管拖车是一种方便、快捷的短距离天然气运输方式,得到了广泛的应用。本课题针对长管拖车高压天然气瓶进行静强度、惯性载荷分析,并在此基础上开展疲劳寿命研究,具有一定的工程意义。以目前广泛采用的长管拖车天然气瓶为模型,采用有限元软件ANSYS分别对内压、内压与重力联合作用下长管拖车天然气瓶进行了静强度的分析,分析结果表明,长管拖车在内压和重力作用下,瓶身主体部分应力水平较低,远小于材料的屈服极限;气瓶缩口与法兰连接处具有较大的应力集中,但总体应力水平低于材料的屈服极限,满足强度的要求。通过对道路运输条件下的惯性载荷进行分析,设定三个方向的加速度进行动力学分析,分析结果表明,天然气瓶的应力水平与三个方向加速度的合成量具有近似线性关系,合成量的大小直接影响气瓶的应力水平。在惯性载荷作用下,气瓶的最大应力超过了材料屈服极限,存在疲劳失效风险。采用ANSYS软件对气瓶进行了模态分析,得到了其前6阶的自振频率,并根据自振频率计算得到了长管拖车的合理运行速度应该小于120km/h;对内压波动影响下的气瓶进行疲劳寿命的进行分析,分析结果表明,虽然气瓶大部分区域不满足无限寿命的要求,但其疲劳寿命能够满足工作要求;通过对惯性载荷作用下的气瓶疲劳寿命进行分析,结果表明,应该将垂直于轴向的加速度控制在18m/s2以内,以防止气瓶发生疲劳破坏。
[Abstract]:With the rapid increase of world energy consumption and the increasingly serious environmental problems, the proportion of natural gas in the total energy consumption is increasing. Long distance transportation of natural gas is mainly pipeline, but in the short distance transportation of natural gas, Long tube trailer is a convenient and fast short distance natural gas transportation mode, which has been widely used. This subject is aimed at static strength of high pressure natural gas bottle of long pipe trailer. The analysis of inertial load and the study of fatigue life on the basis of this are of engineering significance. Taking the natural gas bottle of the long tube trailer which is widely used at present as the model, the finite element software ANSYS is used to analyze the internal pressure, respectively. The static strength of the natural gas bottle of long tube trailer under the combined action of internal pressure and gravity is analyzed. The results show that the stress level of the main body of the long tube trailer is lower than the yield limit of the material under the action of internal pressure and gravity. There is a greater stress concentration at the connection between the cylinder and the flange, but the overall stress level is lower than the yield limit of the material, which meets the requirements of the strength. The inertia load under the condition of road transportation is analyzed. The dynamic analysis of the acceleration in three directions is carried out. The results show that the stress level of the natural gas bottle has an approximate linear relationship with the composition of the acceleration in the three directions. Under the action of inertial load, the maximum stress of the cylinder exceeds the material yield limit, and there is a risk of fatigue failure. The modal analysis of the cylinder is carried out by using ANSYS software. The first 6 natural frequencies are obtained, and the reasonable operating speed of the long tube trailer should be less than 120 km / h according to the natural frequency. The fatigue life of the gas cylinder affected by the fluctuation of internal pressure is analyzed, and the results show that, The fatigue life of the cylinder can meet the requirements of the work though most of the region does not meet the requirements of infinite life. The analysis of the fatigue life of the cylinder under the action of inertial load shows that the fatigue life of the cylinder can meet the requirement of the infinite life. Axial acceleration should be controlled below 18 m / s 2 to prevent cylinder fatigue damage.
【学位授予单位】：河北科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE97

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