气动载荷压心变化对机翼结构重量的影响

Effects of the location changing of the aerodynamic center on the wing structure weight

借助PATRAN、NASTRAN有限元分析工具,着重研究机翼结构重量因气动载荷压心变化而产生的影响。气动载荷的压心变化通过在飞机巡航状态中某一个载荷情况下真实的气动载荷基础上叠加一个微小量的分布载荷来实现,保证新得到的气动载荷与原始的气动载荷总载保持一致,从而使得气动载荷的压心位置发生变化。通过理论分析和简单的有限元分析验证,得到了气动载荷压心变化下机翼蒙皮、长桁等单元的应力分布和增长规律,进而得到气动载荷压心变化与机翼结构增重之间的函数关系:气动载荷压心向翼尖方向移动1%,机翼结构重量增重2.46%。该结论可以为其他型号的民机机翼设计提供参考依据。

By using FEM software such as PATRAN/NASTRAN,this paper studies the influence on the structure weight due to the change of the aerodynamic pressure center.The change of the aerodynamic pressure center is simulated through adding a small distributed load on the actual aerodynamic load on the wing under the aircraft cruise condition,which guarantees the same magnitude of the load while the pressure center is changed.Through the theoretical analysis and FEM validation,the patterns of stress distribution on the wing skin and stringer,and of the aerodynamic pressure center location are obtained.Further more,the function between the aerodynamic pressure center location and the structure weight is obtained;the wing structure weight will increase 2.46% while the pressure center moves 1% toward the wing tip.This conclusion can be taken as the reference during the civil aircraft wing design.