民用飞机全机静力试验前机身工况配平载荷设计

Balancing Load Design for Full-Size Static Strength Test of Large Civil Aircraft of front fuselage serious condition

摘要:

民用飞机结构强度的分析与验证需要结合全机静力试验。在全机静力试验中，不同工况的试验配平载荷设计方案能否反映考核区在该工况下的真实受力直接影响着试验的可靠性和准确性。全机静力试验中由于加载方案复杂，为了简化试验加载数量，传统的配平方法主要保证考核区的加载准确性，对于非考核区的载荷简化到若干加载点上，本文通过试验数据发现传统的配平方法对飞机机身这种薄壁结构，非考核区的配平对考核区影响较大，即使非考核区距离考核区很远。本文以某飞机前机身严重工况为例，基于飞机全机有限元模型，研究了静力试验的载荷设计方案，通过对比理论设计态载荷与传统试验态配平载荷方案下的内力解，对传统全机静力试验配平方案进行优化。该优化的配平方案是基于飞机在此工况下的真实受力情况，非考核区的配平载荷简化不改变全机的受力形式，计算结果表明优化后的试验态内力解与理论设计态内力解基本吻合。本文的研究结果表明，对于飞机机身薄壁结构，圣维南原理并不使用，全机静力试验的配平要与真实工况受力情况吻合，才能达到试验验证目的。

Abstract:

Abstract：In order to complete the strength analysis and airworthiness verification of aircraft structure, it is necessary to carry out full-size static strength test of aircraft. For different load condition, the reliability and validity of test result are directly affected by whether the balancing design of test load can reflect the real stress condition of the evaluation area. In the full-size static strength test of aircraft, In ordor to simplify the complex loading scheme.Traditional balance loading is used to ensure the loading is accurate in the asseessment area, while the loading is simplify to some loading points in the non assessment area.In this paper, we find out that to the thin-wall structure like civil aircraft, traditional balacncing load in the non asseessment area have an effect on asseessment area,even if the the non asseement area is far away from the asseement area.Taking a front fuselage serious condition of a large civil aircraft as an example,the load design scheme of full-size static strength test of aircraft is studied based on the FEM model,By comparing the result of FEM analysis under theoretical design load and common test load, the optimized test load balancing scheme is put forward, the optimized blancing load is based on the real load in the condition we choose,and the balancing load in the non asseessment area doesn’t change the balace mode of the aircraft. The calculated results show that the internal force under optimized test load is basically identical with it under theoretical design load. According to the research in this paper, we can conclude that the Saint Venmant principl is inapplicable to the thin-wall structure like civil aircraft, in ordor to achieve the vertification purpose, the balancing load we exert should consistent with the real situation.