Strength And Stability Assessment Of Hyperbaric Oxygen Chambers Of Different Structures Based On Analysis And Design Methods

Air pressurized oxygen tank and other special medical equipment gradually enter the public view with the progress of medicine.Oxygen tank is a pressure vessel,which needs to meet not only the requirements of JB4732 "Steel Pressure Vessel Analysis and Design Standard",but also the relevant provisions of medical air pressurized oxygen tank.Due to the great risk of accident in oxygen chamber,once an accident occurs,it will be a serious accident.Therefore,this paper carries out strength check,fatigue check analysis and stability analysis based on stress classification method for two kinds of air pressurized oxygen chamber.The strength calculation based on limit load method is also done.(1)In this paper,the finite element models of two types of air pressurized oxygen chambers are firstly established,and the strength is checked based on the stress classification method.Through stress linearization,the membrane stress and membrane bending stress of relevant structures are obtained.After checking,both oxygen tanks meet the relevant requirements of JB4732.(2)In this paper,the fatigue analysis of the two structures of air pressurized oxygen chamber is carried out.In the fatigue condition,the peak stress of the equipment is obtained,the cyclic stress amplitude of the equipment is calculated,and the expected life of the equipment is obtained by interpolation.The allowable cycles of the traditional circular oxygen chamber are 116058.The allowable cycles of the structurally optimized flatbottomed oxygen chamber are 17,339.(3)Since the traditional circular oxygen tank is subjected to external pressure only when the transition tank is loaded,linear buckling calculation is carried out in this paper,and the critical buckling pressure when instability occurs is 1.91 mpa.On the basis of linear buckling,the nonlinear buckling of the structure is checked,and the buckling mode and critical buckling load more close to the actual situation are obtained.The critical buckling load is0.729 MPa.(4)Due to the conservative strength calculation based on stress classification method,this paper analyzed the Mises stress distribution of two types of air pressurized oxygen tanks based on the limit load method,calculated the Mises stress distribution of oxygen tanks under ideal elastic-plastic material,and obtained the structural displacement cloud diagram.After checking,it was found that the strength met the requirements.The allowable limit load of the traditional circular oxygen chamber is 0.356 MPa,and that of the flat-bottom oxygen chamber is 0.7942 MPa.