飞行器热防护结构宽频声振响应及疲劳寿命分析方法研究

The thermal protection system (TPS) plays a key role in the design of transatmospheric hypersonic vehicles. Among various TPSs, the shingle TPS has been a hotspot due to its outstanding behaviors, but few researchers have conducted the structural-acoustic analysis and fatigue life prediction of the shingle TPS under wideband acoustic excitations (10Hz～10KHz). In this project, a typical shingle TPS structure is taken as the object for study. Firstly, in the low frequency range, efforts will be focused on the more efficient algorithm of structural-acoustic analysis based on the coupling of the finite element method（FEM）and the fast multipole boundary element method (FMBEM). Secondly, within the middle and high frequency ranges, the modelling treatments will be investigated in detail for the multi-hybrid model based on the modal overlap factor with fine partition of frequency bands, and a nested algorithm for vibro-acoustic response analysis using the Statistical Energy Analysis (SEA) and Hybrid energy finite element method (Hybrid EFEM) will be established. Thirdly, a fatigue life estimation procedure will be developed for structures under wideband acoustic excitations. After a series of typical experimental validation and model refinement, a set of solving algorithms which integrate the FEM, FMBEM, SEA and EFEM will be established for the vibro-acoustic response analysis and fatigue life prediction for complicated shingle TPS structures under wideband acoustic excitations. The developed algorithms are expected to provide a solid foundation for the TPS vibro-acoustic analysis of the reusable hypersonic vehicles.

热防护系统（TPS）是保证跨大气层高超飞行器安全飞行的基础，其中盖板式TPS以其突出优点而成为该领域的一个研究热点，但是针对其在宽频噪声激励（10Hz～10KHz）下的声振耦合分析以及疲劳预报却鲜有报道。本项目以典型盖板式热防护结构为研究对象，在低频段开展基于有限元（FEM）与快速多极边界元（FMBEM）耦合的声振耦合分析高效算法研究，在中高频段开展基于模态重叠因子频段精细划分的多混合模型建模方法和基于SEA-Hybrid EFEM的嵌套算法研究，同时发展宽频噪声激励下结构的疲劳寿命分析方法。经过有代表性的实验验证和模型修正，最终建立一套针对宽频激励下盖板式TPS结构的集FEM、FMBEM、SEA、EFEM等方法为一体的声振环境预示及疲劳寿命预报分析方法，为可重复使用高超飞行器的TPS设计提供技术基础。

热防护系统（TPS）是保证跨大气层高超飞行器安全飞行的基础，其中盖板式TPS以其突出优点而成为该领域的一个研究热点，但是针对其在宽频噪声激励（10Hz～10KHz）下的声振耦合分析以及疲劳预报却鲜有报道。本项目以典型盖板式热防护结构为研究对象，在低频段开展基于边界元的声学响应分析和结构优化，发展了基于NURBS和细分曲面的声学等几何边界元，采用宽频快速多极算法加速求解，推导了灵敏度分析的伴随变量法，在此基础上，进行了结构优化算法研究，分别进行了形状优化、拓扑优化和联合优化。进而，开展了有限元（FEM）与快速多极边界元（FMBEM）耦合的声振高效分析算法研究，提出FEM-FMBEM强耦合系统高效分析和拓扑优化算法，为耦合系统优化设计提供了有效手段。在中高频段开展基于模态重叠因子频段精细划分的多混合模型建模方法，基于SEA并引入应力集中因子对结构宽频范围内的声振响应及应力水平进行预估。同时，基于波法对典型梁板壳及耦合结构的传递特性进行了理论分析，进而将能量辐射传递法(RETM)由各向同性材料结构的分析拓展到各向异性梁板结构的高频响应分析。最终建立一套针对宽频激励下盖板式TPS结构的集FEM、FMBEM、统计能量分析（SEA）、RETM等方法为一体的声振响应预示及疲劳寿命预报分析方法，为可重复使用高超飞行器的TPS设计提供技术基础。