Feasibility analysis of high excess pressure cockpit using material substitution based on strain energy

The design concept of high excess pressure cockpit has been proposed as a solution to solve the ergonomics problems caused by cockpit environment. To address the contradiction among mass, economy, maneuverability and environment ergonomics, considering the composite advantages of high strength and lightweight, the feasibility analysis concept of high excess pressure cockpit based on material substitution is proposed in the paper. Based on the strain energy analysis on finite element model, the iteration design method of equal stiffness and lightening effect analysis on material substitution are presented, The weight reduction effect after material substitution can be evaluated intuitively by using equal stiffness curve. The calculation result of cockpit indicates that the lightening effect can reach 35.09%. Because of the complexity of cockpit design, bi-level optimization method is proposed and performed by means of the First-Order Radio algorithm. The research shows that the method can achieve good result. The feasibility of high excess pressure cockpit is studied from the aspect of the relationship between excess pressure and mass, and the research demonstrates that, due to the utilization of T300/4211 in place of 6061 alloy, the excess pressure of cockpit increases from 35 to 45 kPa, a 28.57% increase, while the cockpit mass is decreased by 12.56%. Thus, the contradiction among mass, economy and environment ergonomics can be coordinated, which can provide a reference for the design of high excess pressure cockpit.