编织预制件渗透率测量方法的比较研究

A Comparison of the Measurement Method for Permeability of the 3D Braided Preform

采用单向和径向流动测量了三维编织预制件的渗透率,比较研究了测量三维编织预制件渗透率的特点,分析了纤维体积含量、渗透率方向、注入压力在2种测试方法中的作用。实验结果表明:径向法适用于较低纤维体积含量,通过提取流动前沿轮廓能够确定渗透率方向,径向法中注入压力为0.1—0.3 MPa较适合;单向法适用于较高纤维体积含量,仅能测量2个方向的渗透率,而不能确定主渗透率方向,三维编织预制件渗透率测量采用2种方法相结合,单向法测量渗透率的大小,径向法测量主渗透率的方向。

Permeability of three-dimensional braiding preform was measured by radial and unidirectional flow techniques. Characteristic of the permeability was comparison between the two flow methods. The effect of the fiber volume fraction and orientation of the principal permeability as well as injection pressure on the measurement was analyzed. The experimental result showed that the performs of the lower fiber volume fraction were proper for radial flow. The orientation of the principal permeability tensor was obtained by extracting flow front ellipse. Injection pressure from 0.1 MPa to 0.3 MPa was proper for radial flow. The performs of the higher fiber volume fraction were proper for unidirectional flow, Although two directional permeabilities could be measured, orientation of the principal permeability cannot be determined, Permeability of the 3D braided perform was measured through combining radial with unidirectional flow. The permeability value was measured by unidirectional flow and the orientation of the principal permeability tensor was obtained by radial flow.