| Spacecraft is subjected to shock and random excitation and other complex and severe vibration environment in the launch phase. It is important for optimizing the design of spacecraft and make a reasonable assessment of the ground test conditions to get more accurate dynamic load transferred by from the interface. However, it is difficult to measure the interface load of satellite and launch vehicle directly in the lunching process in site. Moreover, it can not be fully obtained by measure method in the condition of stringent weight restrictions and other constraints. In this thesis, the method for dynamic force in the interface of satellite and launch vehicle in the condition of transient excitation and broadband stationary random excitation is studied. It predicts the interface load of time domain and frequency domain by the response of measured acceleration in little points. Then the validity and accuracy of analytical method can be verified and evaluated by the test results. The main work is as follows.Analyzing the satellite-rocket interface load is realized through dynamic model whose accuracy and reasonability thus directly determines the accuracy and effectiveness of the responding analysis. It mainly revises the stiffness of structural components and refines structural connection in order to improve the accuracy of dynamic model by use of the vibrational test results.This thesis proposes the time-domain analysis method under the impact excitation. It imposes the acceleration boundary conditions by use of large-mass method. Using Green function method to establish the convolution integral relationship between the incentive of acceleration, the response of acceleration and interface force. The measured acceleration response inverses impact excitation. Then it can predict interface force. There is two case. One is based on uniform distribution impact excitation, the other is non-uniform distribution impact excitation. Several control nodes in acceleration border are selected.Such acceleration interpolation nodes describe non-uniform distribution incentive and rectangular pulse distribute incentive as interpolation basic function in time domain. It can get the Green function of control nodes. Eventually it can obtain the interface force through inversion of control nodes in impact load.This thesis proposes the analysis method of satellite-rocket under broadband random excitation. Using large-mass method and frequency response function method to establish the relationship in frequency domain between the incentive of acceleration, the response of acceleration and interface force. The measured acceleration response inverses impact excitation in frequency domain. Then it can predict interface force. There is two case in the same. One is based on uniform distribution excitation, the other is non-uniform distribution excitation. Several control nodes in acceleration borders are selected.Such acceleration interpolation nodes describe non-uniform distribution incentive and harmonic incentive as interpolation basic function in frequency domain. It can get the frequency response function of control nodes.Eventually it can obtain the interface force through inversion of control nodes in case of broadband random excitation. Comparing the measured results and the calculated results, the analysis method in this thesis is effective and accurate. |
