Optimization Design Of Connection Structure Of Intergrated Thermal Protection Systems

The structure of the higher efficiency of the integrated thermal protection system has gradually become the focus development of thermal protection system.However,due to the integration of thermal protection system to connect the structure of insulation and bearing capacity of mutual restraint,contradictory,increased its design difficulty.This article takes into account the thermal insulation and bearing properties of the integrated thermal protection system connected to the structure of the optimal design.Firstly,the thermo-mechanical coupling analysis of the typical integrated thermal protection system of corrugated sandwich thermal protection system,it is found that the connection structure of the integrated thermal protection system is the key to slow the heat short and expansion mismatch.The sensitivity analysis of the thickness of the web Wt and its angle ? with the panel was obtained,and the sensitive interval of the structural ultimate stress was obtained.The thermodynamic coupling analysis of the geometric model with low sensitivity and deformation sensitivity is found,and it is found that the structural ultimate stress is greatly reduced.But also found that the current integrated thermal protection systems design of the irrationality and size optimization of both thermal insulation and bearing the limitations.Three thermal insulation models with equivalent heat flux,equivalent heat dissipation and net heat transfer rate are proposed.Through the formula derivation and the example shows under the thermodynamic coupling condition,it is found that the objective function of the strain stiffness as the equivalent stiffness under the thermo-mechanical coupling condition is smaller than the structural flexibility and the average displacement of the upper surface.The ultimate stress of the optimization result is smaller and the stiffness is bigger.Based on three kinds of thermal insulation model and strain energy,an integrated topology optimization model of thermal insulation is established.The topological optimization design of the integrated thermal protection connection structure under three kinds of thermal insulation models is carried out for the established topology optimization model.It is found that the net heat transfer rate is more clear and the intermediate density is smaller as the optimiza tion result obtained in the thermal insulation part of the topology optimization model,Through the optimization of the results of the model reconstruction and thermal coupling analysis,found that multi-mode topology optimization design can be a good balance of re-entry process of the ultimate stress and buckling deformation.According to the selection of the final optimization model to carry out both the temperature load dominant and pneumatic pressure dominated multi-mode topology optimization design,According to the topology optimization results to establish a more simple structure of the model for parameter sensitivity analysis,Select the optimal size,the size of the thermodynamic coupling analysis results compared with the topological optimization results,the volume is further reduced,the structural efficiency to further improve.