Nomex蜂窝夹层板弯曲性能温度相关性的实验研究

Experimental study on the temperature effect on the flexural properties of Nomex honeycomb sandwich structure

采用三点弯曲法对六边形Nomex蜂窝夹层板在不同温度下的弯曲性能进行了研究。根据蜂窝芯的正交各向异性特征,分别取面内的两个主方向为长度方向制作了L试件和W试件。在25℃、50℃、100℃、150℃和180℃下开展了弯曲实验,确定了弯曲刚度与剪切刚度。结果表明:随着温度的升高,两个方向上的弯曲刚度与剪切刚度均明显下降;当温度升高到180℃时,弯曲刚度与剪切刚度均低于常温时的20%。对于蜂窝夹层板在横向力学载荷作用下的破坏模式,当温度低于50℃时,多出现面板凹陷;当温度达到150℃甚至更高时,多出现面板与蜂窝芯脱离并向外凸出。文中研究成果可以为Nomex蜂窝夹层板在变温或激光辐照下的工程应用提供参考。

The flexural properties of Nomex honeycomb sandwich structure at different temperatures were studied with three-point bending method. Considering the honeycomb＇s orthotropy, L and W specimens were made, respectively taking the two main directions in the core plane as the longitudinal direction. Bending experiments were carried out to determine the bending stiffness and shear stiffness at 25 ℃, 50 ℃, 100 ℃, 150 ℃ and 180 ℃ respectively. The results show that both the bending stiffness and the shear stiffness in the two directions decreases as the temperature rises. When the temperature rises to 180 ℃, the two kinds of stiffness are less than 20% of that at room temperature. The temperature also has effect on the failure mode when the sandwich structure is under transverse mechanical load. A sunken skin is often seen when the temperature is below 50 ℃; when the temperature rises to 150 ℃ or higher, the skin may be separated from the honeycomb and be protruded outward. The research results may provide a reference for the application of Nomex honeycomb structure in laser irradiation or fluctuating temperature environments.