To explore the service behavior of thermal protection materials in hypersonic environments

wind tunnel experiments and numerical simulation methods are used to investigate the failure of D6AC steel structure under multi-physics coupling. Based on the basic theory of hypersonic aerodynamics and structural mechanics

the multi-physics coupling theory model of hypersonic D6AC steel structure is established. The aerodynamic heating and structural response in different flight environments are obtained by N-S equation simulation

and the results of numerical simulation are verified in wind tunnel test. The aerodynamic heat is the main factor leading to the failure of D6AC steel structure. Under three different flow conditions

the ablation phenomenon occurs in the steel structure

and the starting time of the structure ablation depends on the total temperature of the incoming flow.