Non-structural mass trimming method for airplane in steady overload state

Abstract

The invention discloses a non-structural mass trimming method for an airplane in a steady overload state. By introducing increment of a non-structural mass unit, the aerodynamic load and the inertial load of the airplane are trimmed, so that a result obtained by analyzing a finite element model without displacement constraint is more reasonable than a result obtained by a displacement constraint method and an inertia relief method. According to the non-structural mass trimming method, a poly-condensed load array is obtained through a poly-condensation technology so as to accurately obtain a non-balance system of force of an airplane structure relative to a reference point; and a trimming load is further obtained by airplane overload, and the trimming load is equivalently converted into an increment attribute of a trimmed non-structural mass unit. According to the method, mass load increments are transferred to structural units by utilizing connection of RBE3 rigid units, namely, an inertial load of the trimmed mass unit is transferred to a force-bearing point of a structural model of an oil tank, a warehouse or an equipment compartment so as to accurately obtain stress characteristics of the airplane structure. The non-structural mass trimming method has important application values and significances for improving the design accuracy of the airplane structure.

Description

technical field [0001] The invention relates to the field of aircraft structure design, in particular to a method for balancing non-structural mass of an aircraft in a steady overload state. Background technique [0002] The aircraft is subjected to various loads during flight, and the loads that affect the structural strength of the aircraft mainly include aerodynamic force, air resistance, engine thrust, and structural inertial loads during flight. When using finite element discretized numerical analysis method to design and analyze the aircraft structure, it will encounter the unbalanced situation between the aerodynamic force and the inertial load of the aircraft. This unbalanced state may come from the unbalanced modeling of the initial aerodynamic loads and inertial loads, or it may be that although the aerodynamic loads and structural inertial loads are unbalanced under the initial conditions, the aerodynamic The loads are not in balance with the optimized structural...

AI Technical Summary

Problems solved by technology

However, this method of setting displacement constraints will transfer unbalanced loads to the foundation through the constraint nodes, resulting in inappropriate force transmission routes, and lead to stress concentration and incorrect deformation of the relevant elements of the constraint nodes, reducing the design analysis results calculation accuracy

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