【摘要】：面對日益惡化的環(huán)境和石油資源的枯竭，使得作為清潔能源應(yīng)用典型的CNG氣瓶的使用逐年增加，CNG汽車在國內(nèi)逐漸推廣使用。CNG-2氣瓶由金屬內(nèi)襯和外層纏繞的高強(qiáng)度纖維增強(qiáng)復(fù)合材料組成，，由于其質(zhì)量輕、強(qiáng)度高和安全可靠等優(yōu)點得到了廣泛的應(yīng)用。使用過程中，CNG氣瓶也出現(xiàn)了一些故障和爆炸事故，從而導(dǎo)致氣瓶的安全分析和研究越來越受到關(guān)注。論文以CNG-2氣瓶為研究對象，探討了氣瓶的應(yīng)力分析、疲勞分析、缺陷分析三個方面的內(nèi)容。 論文借助ANSYS有限元分析軟件，對鋼內(nèi)膽玻璃纖維纏繞的CNG-2氣瓶進(jìn)行了分析，利用有限元前處理程序建立了可以用于復(fù)合材料氣瓶計算的力學(xué)模型。通過建模分析，得到了氣瓶在自緊壓力、水壓、零壓、工作壓力及爆破壓力下的應(yīng)力分布，驗證了自緊的必要性；對計算過程是否需要考慮幾何非線性的影響作了討論，結(jié)果顯示幾何非線性會對應(yīng)力分布產(chǎn)生一定的影響。 論文研究了CNG-2氣瓶的自緊原理及其實現(xiàn)方案，探討了自緊壓力對氣瓶最大應(yīng)力分布、整體應(yīng)力分布及氣瓶疲勞壽命的影響，并對自緊壓力進(jìn)行了優(yōu)化。計算表明，隨著自緊壓力的增大，卸載后（即零壓力下）內(nèi)膽的環(huán)向壓應(yīng)力線性增大；工作壓力下內(nèi)膽的Von Mises應(yīng)力減小而纖維層的應(yīng)力線性增大，從而證明，合理的自緊工藝可以顯著改善工作壓力下內(nèi)膽和纖維的應(yīng)力分配，而平均應(yīng)力則隨著自緊壓力的增大而降低。綜合考慮，得出了最佳自緊壓力為36MPa的結(jié)論。 論文介紹了鋼內(nèi)膽和復(fù)合材料的疲勞機(jī)理及提高抗疲勞性能的途徑，在此基礎(chǔ)上，分別對復(fù)合材料和內(nèi)膽進(jìn)行了疲勞分析，結(jié)果表明自緊后內(nèi)膽的疲勞壽命由20240次增至100000次，提高了內(nèi)膽的疲勞壽命。 論文參照GB/T19624-2004《在用含缺陷壓力容器安全評定》標(biāo)準(zhǔn)對CNG-2氣瓶存在的凹坑缺陷進(jìn)行了安全分析和評定，分析表明，這類缺陷對氣瓶的內(nèi)膽和纖維層的最大應(yīng)力及應(yīng)力幅有較大影響，在缺陷長度和寬度保持不變的情況下，隨著凹坑深度的增大，內(nèi)膽的應(yīng)力幅隨之增加，而纖維層的最大Von Mises應(yīng)力亦增大，因此，缺陷會縮短氣瓶使用壽命，帶來安全隱患。
[Abstract]:In the face of the worsening environment and the depletion of petroleum resources, the use of CNG cylinders, which are typical of clean energy applications, is increasing year by year. The CNG-2 cylinder is composed of high strength fiber reinforced composites with metal lining and outer winding, which is widely used because of its advantages of light weight, high strength, safety and reliability. In the process of application, there are also some failures and explosion accidents in CNG cylinders, which leads to more and more attention to the safety analysis and research of gas cylinders. In this paper, the CNG-2 cylinder is taken as the research object, and the stress analysis, fatigue analysis and defect analysis of the cylinder are discussed. In this paper, the ANSYS finite element analysis software is used to analyze the glass fiber wound CNG-2 cylinders in steel, and a mechanical model for the calculation of composite gas cylinders is established by using the finite element preprocessing program. Through modeling and analysis, the stress distribution of the cylinder under self-tightening pressure, water pressure, zero pressure, working pressure and blasting pressure is obtained, and the necessity of self-tightening is verified. Whether the influence of geometric nonlinearity should be considered in the calculation process is discussed. The results show that geometric nonlinearity will have a certain effect on the stress distribution. In this paper, the self-tightening principle of CNG-2 cylinder and its realization scheme are studied, and the effects of self-tightening pressure on the maximum stress distribution, integral stress distribution and fatigue life of the cylinder are discussed, and the self-tightening pressure is optimized. The calculation results show that the circumferential compressive stress increases linearly after unloading (i.e. zero pressure) with the increase of self-tightening pressure. The Von Mises stress of the inner bile decreases and the stress of the fibrous layer increases linearly under the working pressure, which proves that the reasonable self-tightening process can significantly improve the stress distribution between the inner bile and the fiber under the working pressure. The average stress decreases with the increase of self-tightening pressure. It is concluded that the best self-tightening pressure is 36MPa. This paper introduces the fatigue mechanism of steel inner tank and composite material and the ways to improve the fatigue resistance. On the basis of this, the fatigue analysis of the composite material and the inner bravery is carried out respectively. The results show that the fatigue life of the inner tank increases from 20240 times to 100000 times after self-compaction. The fatigue life of the inner gallbladder is improved. In this paper, the safety analysis and evaluation of the concave defects in CNG-2 cylinders are carried out with reference to the GB/T19624-2004 Standard for Safety Assessment of pressure vessels with defects. The analysis shows that, These defects have a great effect on the maximum stress and stress amplitude of the inner tank and fiber layer of the cylinder. When the length and width of the defect remain constant, the stress amplitude of the inner bile increases with the increase of the pit depth. The maximum Von Mises stress of the fiber layer also increases, therefore, the defect will shorten the service life of the cylinder and bring about the hidden danger of safety.
【學(xué)位授予單位】：華南理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2011
【分類號】：TH49;TB33

【引證文獻(xiàn)】

相關(guān)期刊論文 前1條

1 郭崇志;甘平燕;付小立;;復(fù)合材料纏繞層缺陷深度對CNG-2氣瓶強(qiáng)度影響的研究[J];壓力容器;2013年03期

相關(guān)碩士學(xué)位論文 前1條

1 甘平燕;帶缺陷的CNG-2氣瓶安全評估與分析[D];華南理工大學(xué);2013年

本文編號：2318634