颗粒冰与钛合金冻结强度的剪切试验分析

飞机在湿度较大的高空云层飞行时,空气中液滴碰撞飞机发动机叶片后易产生具有颗粒结构的冰体。为研究叶片上冻结冰对飞机发动机运行性能的影响,本文在低温实验室内采用喷雾法在钛合金表面制备颗粒结构冰,模拟飞机发动机叶片上冻结冰的形成过程。通过自主研制的剪切试验仪对不同环境温度下冻结的冰体与钛金属表面的剪切强度进行试验测量,得到了温度(T)与剪切强度(τs)的对应关系。试验结果显示,冻结冰与钛金属粘剪切强度随着环境温度降低而增加,并呈现出明显的线性关系。应力时程曲线显示,颗粒冰与钛合金表面粘结处发生的剪切破坏为典型的脆性破坏过程。本文为研究飞机发动机上冰体的力学性质、飞机防冰设计以及相应数值模拟提供了重要的参考数据。

Experiments analysis of shear strength between granular ice and titanium alloy surface

In high humidity atmosphere,the engine of aircrafts faces challenges from icing when water drops hit on its surface.In this paper,a spraying apparatus is established to model the icing process on titanium alloy surfaces.Through applying shear forces on the cohesive zone,the shear strength (τs) under different temperature (T) is obtained.The result shows that the τs linearly decreases with T.It shows that the shear failure happened in the cohesive zone between the granular ice and titanium alloy surface is a typical brittle failure.The experiment data would be useful for the analysis of physical and mechanical properties of granular ice,helpful for the ice-resistant design of the aircraft engine,as well as calibration for simulation.