三维编织复合材料T型梁的低温场弯曲性能

为研究三维编织复合材料T型梁低温环境下的弯曲力学性能,以指导耐低温抗弯曲三维编织复合材料结构设计,采用真空辅助树脂传递模塑成型工艺制备不同筋高高度三维编织复合材料T型梁,自制低温环境箱,与MTS 810.23型材料测试系统相结合测试三维编织复合材料T型梁在不同低温下的弯曲力学性能。结果表明:随测试温度的降低,三维编织复合材料T型梁载荷增加,位移增大,能量吸收增加;随筋高高度的增加,三维编织复合材料T型梁载荷增加,位移减小,能量吸收增加,抗弯刚度增强;三维编织复合材料T型梁由较高温度下不同程度的屈服断裂转变为低温下的脆性断裂,随着筋高高度增加,失效模式由弯曲失效转变为剪切失效。

Bending properties of three-dimensional braided composite T-beam at low temperature

In order to study the bending properties of three-dimensional (3-D) braided composite T-beam at low temperature so as to design low temperature resistant and bending resistant 3-D braided composite structure, the 3-D braided composite T-beam with different flange heights was fabricated by vacuum assisted resin transfer molding. The MTS 810.23 material testing system in combination with a self-developed low temperature environment testing system was adopted to test the bending properties of the 3-D braided composite T-beam at different temperatures. The results show that the failure load, displacement and energy absorption increase with the decrease of the temperature, and the bending rigidity, failure load and energy absorption increase with the increase of the flange height of the T-beam. The displacement decreases with the increase of the flange height. The failure behavior of 3-D braided composite T-beam changes from yield fracture at high temperature to brittle fracture at low temperature. The failure mode changes from bending failure to shear failure with the increase of height of flange height.