编织结构玻璃长丝缝合线的打结强度

Knot strength investigation of braided glass filament fiber sewing threads

针对玻璃纤维丝束在纺织预制件或预浸料的缝合过程中易发生断裂的情况,设计了二维管状编织结构的玻璃纤维缝合线。采用Instron电子万能试验机对不同编织工艺参数的缝合线试样分别进行了loop结和knot结的拉伸强度测试,分析了拉伸断裂的机制和破坏模式。结果表明:编织结构玻璃长丝缝合线的打结强度和断裂伸长率明显高于玻璃丝束;花节长度是影响打结性能的主要因素;试样在试验过程中受剪切和拉力共同作用,经历伸直—受力—断裂几个阶段,试样断口基本平齐。

Two-dimensional braided sewing thread made of glass fiber was tailored to conquer the rupture problem of the glass tow in stitching process of composite preform or prepreg. Instron apparatus was used to test the tensile strength of the knot and loop of specimens with different braiding parameters, and the breaking mechanism and rupture mode were analyzed. The results showed that 2-D braided glass fiber thread had better breaking tenacity and elongation than the glass tow. The knot performance was mainly influenced by pitch length. Shear and tensile force were acted on the specimens jointly during the test that made the thread undergo three phases： unwinding, force bearing and breaking. And the broken end was seen nearly flush.