Research On Safety Of Rocket Launching Pad Based On Optical Fiber Sensing And Structure Simulation

The reliability and security of aerospace equipment requires very strict requirements.Especially the rocket launching pad working status affect the mission,which is related to workers' life.It requires the launching pad building structure safety monitoring system,which can immediately identify structural damage and give alarm,to save the loss.With research and improvement of the launching pad design technology,considering the effect on the launch safety,in order to guarantee the normal work of the launch,security research and monitoring of the structure is more important,and a great economic and social benefits can be obtained.A certain type of rocket launching pad is become the research object,through the simulation software to calculate the launch under various working conditions.And it successfully uses the high precision optical fiber grating sensors to set up a structural stress monitoring system for the launching pad,realizing the purpose of monitoring the stress of study object.At the same time,the results of the simulation and the reliability of the monitoring system are verified by comparing the data of the equipment recorded in the field experiment,to complete the security analysis of the launching pad.The main research contents and achievements are as follows:Firstly,learn the working principle of fiber Bragg grating sensor and demodulator.Selecting the sensing device suitable for the working environment of the launching pad.Determine the sensitive parts and dangerous areas of the launching pad structure according to the survey results,to design the launching pad monitoring system.Installation of fiber optic sensor and circuit protection scheme is arrangemented,and the data is collected.Secondly,determining the working condition of the finite element simulation,the finite element analysis software Ansys Workbench is used to simulation the model.According to the actual situation of model,structural contact type and mesh size can be set up,to calculate the stress nephogram and displacement nephogram of the various working conditions,especially stress state of the bolts,strap and seam.The simulation results are compared with the experimental results and the reasons for the differences are analyzed.After verifing the effectiveness of the simulation model,bolts failure,strap failure,and weld cracking failure conditons are simulated,to provide theoretical basis for the structural safety judgment.Lastly,using Fluent software for the simulation analysis of high temperature gas flow movement.Establishing the physical model of the whole flow field and setting key material properties,selecting rational turbulence model and boundary condition,heat transfer conditions and load distribution of the structure by air can be calculated.The influence of airflow on the thermal protection measures and structural safety of the launching pad is further obtained.Through the combination of simulation conclusion and monitoring data,the security analysis of the launching pad structure is realized.,to improve the accuracy of the rocket launching pad structure monitoring and safety evaluation.This system would reduce or even eliminate the structural failure of the launching pad,so it greatly improves the safety of launching pad,and ensures the smooth progress of space launch test.