飞机结构强度试验应急载荷限定系统

多轮多支柱起落架飞机主起落架数量较多，试验机及试验设备重量大。试验应急卸载时，试验件和设备重量、以及加载过程中试验件变形所聚集能量快速释放的不协调性易对支持点结构产生较大冲击载荷，且该载荷不可控，影响试验的考核，存在安全隐患。针对多轮多支柱起落架飞机的强度试验要求，设计一种载荷限定系统。在应急卸载或者试验停试情况下，能够为非支持点起落架输出设定载荷，保证应急瞬间所产生的所有载荷按要求分配到所有起落架上，从而防止支持点起落架超载；试验过程中，能够对非支持点起落架施加试验主动载荷。利用仿真软件验证了系统原理的可行性。依据原理设计载荷限定系统，对其结构和工作性能进行应用验证，并在某型飞机全机疲劳试验中进行应用调试，结果表明，该系统完全能够满足试验要求。

Emergency load limited system for aircraft structural strength test

The number of main landing gears for multi-wheels and multi-struts landing gear aircraft is large, and the test machine and test equipment are heavy. During the test emergency unloading, the weight of test pieces and equipment, as well as the inconsistencies in the rapid release of the accumulated energy generated by the deformation of test pieces during the loading process, are likely to produce a large impact load on the support point structure. And the uncontrollable load will affect the test assessment, exposing potential safety hazards. A load limited system is designed to meet the strength test requirements of multi-wheels and multi-struts landing gear aircraft. In emergency unloading or test pause, the proposed system can set a load for the non-support landing gear, ensuring that all generated loads are assigned to all landing gears as required to prevent overloading of the support in the emergency moment. During the test, the test active load can be applied to non-support landing gear. The feasibility of the system principle is verified by simulation software. Based on the system principle, the load limited system is designed, and its structure and performance are verified. And the application debugging is carried out in the whole machine fatigue test of a certain type of aircraft. The results show that the system can fully meet the test requirements.