Nomex蜂窝夹层结构面内剪切性能试验研究

采用改进设计的像框试验对Nomex蜂窝夹层结构的面内剪切性能进行了表征测试与研究。试验结果表明,在像框的持续性剪切载荷作用下,夹层结构首先发生了板-芯界面脱粘,继而蒙皮在竖直方向上形成了巨大的鼓包和皱褶。随着剪切载荷的增加,夹层结构最终发生了横向的断裂。多次试验结果所得的低于3%的离散率也预示出面内剪切像框试验的有效性和准确性。此外,试样和夹具之间的固定程度是影响面内剪切像框试验的关键因素。仅采用螺钉进行固定的试样测试时,螺钉受拉力的移动直接导致了夹层结构边缘破坏,然而样件本身所受像框的面内剪切载荷有限,试验无效。

Experimental Study on In-Plane Panel Shear of Nomex Honeycomb Cored Sandwich Structure

The modified picture-frame experiment was applied to test and study the in-plane panel shear of Nomex honeycomb cored sandwich structure. The results show that under by the continuous shear loads from the picture frames, skin-core debonding of the sandwich structure occurred firstly and the skin materials formed to the big bubbles and wrinkles in the vertical direction ,i.e., the direction of tensile travel. With the increase of shear loads, the sandwich structure finally fractured in the transverse direction. The dispersion ratio of lower 3% gained from several experiment results indicates the effectiveness and accuracy. In addition, the fixedness between specimen and fixtures is the key factor for picture-frame experiment of in-plane panel shear. For the screw-fixed test specimen, the motion of screws driven by tensile loads induced the failure of the edges of sandwich structure.However, the specimen gained in-plane panel shear loads from picture frames were very limited indicating invalid experiment.