飞机结构有限元分析中分布载荷的离散化处理算法

飞机结构设计中,需要对两类分布载荷数据进行处理:一类是已经由上游专业做过离散化处理,以网格形式提供的数据,例如翼面、舱门等的气动载荷,机体结构、燃油、设备、商载等的惯性载荷;另一类是以均布或线性分布等较为简单分布形式作用的载荷,例如增压舱、燃油箱等结构的压差载荷。针对飞机结构设计中需要进行离散化处理的两种不同类型载荷数据,分别对三类典型单元(三角形、矩形和四边形)的等效结点载荷移置处理算法进行研究,根据能量等效原则,利用薄板弯曲单元的理论,提出分布载荷离散化处理的算法,并对实际应用中舍弃结点载荷力矩分量处理方法的合理性进行说明,并通过算例验证,证明所提出的算法可在实际工程中推广应用。

Discretization algorithm of distributed load in finite element analysis of aircraft structure

Abstract In the aircraft structure design, we need process two kinds of data. One is the data which have been discretized by the upstream specialty and provided in grid form, such as the aerodynamic loads on the Wing and the hatch, the inertia load of structure, fuel, equipment, payload and so on. The other is the data of load which acts in form of uninform or linear distribution such as pressure of pressured cabin or fuel tank. Aircraft structure applying distributed body force and distributed surface force are mainly composed of panels, frame webs and so on. Generally, they are simplified into triangular, rectangular and quadrilateral plane stress elements. In this paper, the equivalent nodal load shift processing algorithm of three kinds of typical units is studied according to the principle of energy equivalence, and the algorithm of discrete processing of distributed load is put forward, and the rationality of the processing method of the load moment component of the discard node in practical application is explained and verified. It is proved by an example that the proposed algorithm can be popularized and applied in practical engineering.