## 1 Introduction  
The shock environment exists widely in aerospace engineering. A high-frequency transient shock load will occur during the initiating process of a pyrotechnics device. The response of spacecraft under this shock load is defined as the shock environment [1]. During the process of explosive separation, the explosion and separation can produce a complex shock environment with a short duration, high frequency and high amplitude, which may cause the damage or failure of the satellite system (especially the electronic equipment), resulting in failure of the satellite. Therefore, the transient response analysis of the spacecraft structure under the explosive separation and shock load is an important aspect of satellite development [2]. A reasonable prediction method of the shock response is urgently needed in the process of spacecraft development and the early stage of system level tests so as to reduce the scientific research cost and shorten the development cycle. Because of the complexity of the structure and material properties of spacecraft, the modal density of each part of the spacecraft varies greatly. Due to the large area mass and dense modes of the structure, such as the stellar panel, it is very sensitive to high frequency excitation. Therefore, a single finite element or statistical energy analysis method cannot solve the problem well. The hybrid FE-SEA method based on the wavenumber can effectively solve the problem of a complex spacecraft response [3]. Due to the complexity of the shock environment, the shock signal has obvious high frequency or broadband characteristics. The traditional finite element analysis and other dynamic analysis methods cannot accurately predict the high frequency response caused by the shock load [4; 5]. In engineering practice, the magnitude of the shock load is estimated based on the engineering experience combined with the data of a similar test [6]. [PERSON] [7] studied a shock test method. A pendulum was used to shock the plate to achieve different shock environments. Statistical energy analysis was used in the numerical simulation [8]. [PERSON] et al. predicted the dynamic response of a composite sandwich beam under shock load. The shock responses of fully clamped monolithic and sandwich beams with elastic panels and compressible elastoplastic cores were analyzed [9]. The FE-SEA method [10] was used to calculate the high frequency or middle high frequency response of the structure. The transient statistical energy analysis (TSEA), the finite element method, the local phase information reconstruction (LMPR), and the virtual mode synthesis (VMSS) were utilized to calculate the transient shock response of the structure. [PERSON] [11] investigated a method of transient response prediction. The shock load was applied to the structure. The results of the numerical analysis were verified by experiments. [PERSON] [12] focused on dynamic response estimation against short-time loading with an updated finite element model, using frequency response functions and the particle swarm optimization technique. [PERSON] [13] calculated the exact transient energy response of a two-degree-of-freedom system under impulse, and the accurate transient energy response of the two-oscillator system was studied by using TSEA. At the same time, the two methods were simulated. [PERSON] [14] synthesized the correlation phase based on the pseudo modal phase change. Combined with the influence of the high frequency filter output and low frequency finite element calculation, the time history response of the equipment in the whole frequency range was predicted. [PERSON] [15] developed a method to predict the transient response of the shock source under structural shock loading. According to the relationship between the impulse response and contact force, [PERSON] calculated the structural displacement and contact force. [PERSON] [16] supplemented the missing phase information of the statistical energy analysis by supplementing the substructure modal information.