碳纤维—铝合金复合材料气瓶的应力分析与优化设计

发布时间：2018-04-06 06:13

本文选题：复合气瓶　切入点：网格理论　出处：《北京化工大学》2011年硕士论文

【摘要】：本文以1.8L复合材料气瓶为例,采用ANSYS12.0中APDL语言建立起复合材料气瓶的有限元模型,并对封头段、封头与筒身过渡段、封头与极孔过渡段做了变厚度和变角度的处理,使得有限元模型更加接近真实情况。在复合材料气瓶制造过程中,自紧是一项重要工艺,自紧后内胆产生残余压缩应力；当气瓶正常工作时,内胆在工作压力下产生的拉伸应力与预紧后产生的残余压缩应力相迭加,内胆应力降低,外侧纤维应力提高,使得气瓶的应力分布更合理。根据《DOTCFFC》标准,分析了自紧过程和确定了自紧压力的范围；给出了复合气瓶在工作状态下、水压试验状态下和最小爆破压力状态下的内胆MISES应力分布和纤维层的纤维向应力分布,并将自紧和非自紧状态下气瓶的应力状况进行了对比,证明了自紧作用能显著提高气瓶的力学性能。考虑了几何非线性对复合材料气瓶性能的影响以及根据内胆应力值确定了疲劳破坏的位置。本文采用ANSYS中的优化模块对复合材料气瓶进行了优化设计。在优化设计中,以纤维层的体积最小为优化目标函数,以自紧压力、纤维厚度和缠绕角度为设计变量,根据《DOT CFFC》标准规定的各工况下的应力限制范围作为状态变量,采用零阶优化的方法综合考虑自紧压力、纤维厚度以及缠绕角度对各工况应力的影响和复合气瓶纤维层体积的影响；并分析了单个设计变量对复合材料气瓶各工况下的应力的影响。
[Abstract]:Taking 1.8L composite gas cylinder as an example, the finite element model of composite gas cylinder is established by using APDL language in ANSYS12.0, and the variable thickness and angle of the head segment, the head and cylinder body transition section, the head and the pole hole transition section are treated.The finite element model is closer to the real situation.Self-tightening is an important process in the manufacture of composite gas cylinders, in which residual compressive stress is produced in the inner tank after self-tightening, and when the cylinder is in normal operation,The stress distribution of gas cylinder is more reasonable due to the superposition of tensile stress under working pressure and residual compressive stress after pre-tightening. The stress of inner bile decreases and the stress of outer fiber increases.According to < DOTCFFC > standard, the self-tightening process is analyzed and the range of self-tightening pressure is determined, and the distribution of MISES stress in inner bile and fiber direction stress in fiber layer under the condition of water pressure test and minimum blasting pressure are given.The stress state of the gas cylinder under the condition of self-tightening and non-self-compaction is compared and it is proved that the self-tightening can improve the mechanical properties of the cylinder significantly.The effect of geometric nonlinearity on the properties of composite gas cylinders was considered and the fatigue failure position was determined according to the stress values of inner gallbladder.In this paper, the optimization module of ANSYS is used to optimize the design of composite cylinder.In the optimization design, the minimum volume of the fiber layer is taken as the optimization objective function, the self-tightening pressure, the fiber thickness and the winding angle are taken as the design variables, and the stress limit range under the working conditions stipulated by the < DOT CFFC > standard is taken as the state variable.The effects of self-tightening pressure, fiber thickness and winding angle on the stress and the volume of fiber layer of the composite cylinder are considered by the zero-order optimization method.The influence of a single design variable on the stress of composite cylinder under different working conditions was analyzed.
【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH49;TB333

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