复合材料头锥结构气动热应力分析方法研究

RESEARCH OF THE ANALYSIS METHOD OF AERODYNAMIC HEATING STRESS OF A COMPISITE CONE

针对某飞行器前部复合材料锥体结构的打样设计,采用有限元方法进行设计飞行条件下气动热载荷、气动压力载荷联合作用时结构应力应变分析方法的研究。文中针对打样阶段对结构性能进行初始估算的要求,对模型进行多场解耦和适当的工程简化处理。首先以结构外表面为边界,建立气动网格,进行流场分析,确定结构网格的热载荷、边界条件;然后对结构网格进行热分析,获得其瞬态温度场分布;最后施加气动压力和温度场分析结果进行结构耦合热应力分析,获得应力应变数据。文中对流场、温度场、应力场采用的实用化处理方法,在满足打样阶段分析要求的同时,克服多场耦合分析协调困难、总体工作量大等问题,具有较高的效率。计算结果表明,气动热应力对锥体顶部应力产生较大影响,必须在设计中加以考虑,并可为下一阶段的详细设计提供更精确的数据参考。所用计算软件为FLUENT和AN-SYS。

The FEA（finite dement analysis） method is used to analyze the composite cone in the front of one aircraft during the theoretical layout design. The method of analyzing the stress and strain of the structure is discussed under the designed aerodynamic heating and aerodynamic pressure. Considering of the need for the structure performance in the phase of theoretical layout design, some engineering simplifying processing like decoupling is used. Firstly, the flow field around the structure is calculated to get the thermal load of the structure, using the out surface of the structure to build the flow field grid. Then the structure grid is built to calculate the temperature field in the whole flying. At last, the temperature result and aerodynamic pressure are used to calculate the stress and strain of the same structure. The engineering processing method in the thesis overcomes the shortcoming of communication and heavy workload in the analysis of multi-field coupling. The result indicates that the aerodynamic heating is the main contributor of the top structure stress, and it must be notice in the detail design. All models are calculated in the software of FLUENT and ANSYS, and the result can be referred in the later design.