热环境下的金属热防护系统的动力学特性研究

Study on Dynamic Characteristics of Metallic Thermal Protection System

研究了金属热防护系统(metallic thermal protection system,简称MTPS)在典型RLV再入热载荷作用下的动力学特性。首先,针对MTPS在热载荷作用下的动态响应问题,结合数值算例验证了有限元分析方法的可行性和正确性;其次,基于MTPS的有限元传热分析模型,计算了热环境下结构的瞬态温度响应;最后,使用有限元的分析方法对笔者建立的MTPS简化模型在热应力场和结构场耦合下的结构动力学特性进行了研究分析,给出了典型再入热环境下结构的固有振动频率随加热时间的变化曲线。计算结果发现,材料弹性模量等参数的变化比热应力场对MTPS结构固有频率的影响更大,热应力场对结构固有频率的影响最高达到10.3%的比例。

The study on the dynamic characteristics of the metallic thermal protection system with typical RLV reentry load profile was conducted. First of all, the dynamic response of MTPS under heating was analyzed and the method was validated available and correct by numerical examples. Transient thermal analysis was completed based on the FEM model, and the dynamic characteristics of the MTPS model under the thermal-structural couple field was researched by FEM. The changes of material elastic modulus affect the natural frequencies much more than the thermal stress does. However, the thermal stress in structure does have effects on the natural frequencies as high as 10.3%.