Research On Dynamic Response And Optimization Of Rocket Launcher Under Impact Load Of Cold Launch At Sea

The rocket launcher,as an important component of the launch system of the carrier rocket,plays an indispensable role in the process of rocket launch.During the cold launch operation of offshore carrier rockets,the low-power and high intensity explosives arranged at the bottom of the rocket launcher will instantly generate high-pressure gas,which will eject the rocket from the launcher.The rocket launcher will directly withstand the impact of high-pressure gas,and the transient impact will not only cause damage to the rocket launcher structure and surrounding instruments and equipment,but also pose a threat to the safety of the launch platform structure and equipment.Therefore,based on actual engineering needs,dynamic response characteristics of rocket cold launch impact problems are studied,and the dynamic response laws of the launch frame structure are clarified,and structural optimization of the launch frame is carried out.Providing technical support for offshore rocket launch is of great significance for further ensuring launch safety.Firstly,the research methods for structural dynamic response under impact loads were introduced,and the research progress of domestic and foreign scholars in calculating structural dynamic response under impact loads was summarized.A research method mainly based on explicit dynamic analysis was established;The current research status on the optimization of the launch frame structure has been summarized,indicating the direction for this study.Secondly,a dynamic model of the offshore rocket launch system was established,and the problem of setting boundary conditions was discussed.The natural vibration characteristics of the launch frame structure were calculated;Based on the known information,the transient impact load during the rocket ejection process is calculated.The finite element explicit dynamic analysis method is used to analyze the dynamic response of the transient impact caused by the cold launch process of the rocket,and to explore the dynamic response laws of stress,displacement,and acceleration at typical areas of the launch frame structure.Once again,the vibration acceleration response data at typical assessment points of the rocket launcher structure caused by transient impact loads during the cold launch and ejection process of the rocket were obtained through full-scale tests.The results were compared with the calculation results of explicit dynamic analysis methods,verifying the effectiveness and engineering applicability of the finite element analysis model,impact load calculation,and explicit dynamic analysis calculation methods for offshore rocket launch systems,And based on the results of actual ship tests,the dynamic response characteristics of the rocket launcher structure under transient impact loads were analyzed.Finally,based on the dynamic response calculation results of the explicit dynamic analysis method and the data analysis of actual ship tests,it was found that although the structural performance of the rocket launcher meets the design requirements,there is a risk of exceeding the standard.Therefore,optimization design of the rocket launcher structure was carried out.In the ISIGHT optimization platform,the optimal super Latin method was used for DOE experimental design.The response surface method was used to establish an approximate model to replace the finite element model for optimization operations.The structural stress and displacement were optimized as the objectives,and the multi island genetic algorithm was used for structural optimization.Finally,the optimization plan for the launch frame structure was proposed.This article discusses the dynamic response characteristics of rocket launcher structures,conducts verification tests on impact response laws,and conducts optimization research on the impact resistance of launcher structures,providing a basis and reference for the design of impact protection for offshore launch equipment structures.