复合材料编织接头承载能力的试验研究

 试验研究了用于航空结构的三维整体编织复合材料单耳承力接头在静载条件下的承载能力与破坏模式。单耳接头试样采用RTM(Resin Transfer Molding 树脂传递模塑)工艺制成，重点研究了由3种编织工艺（三维四向、三维五向和三维六向）、2种连接孔加工方式（机械钻孔和编织孔）、2种几何外形所组成的10组三维编织复合材料单耳承力接头的破坏机理与破坏载荷。对其在航空结构中的可应用性做出了评估。

Failure Load of Load-bearing Joints in Three-dimensional Braided Composites

Load response and failure modes of 3-d braided composite lugs were studied experimentally. The objective of the study was to get information on the stiffness, strength and failure mode of the lug, as well as on the applicability of the analysis method used to predict lug load response and failure. The test lugs were manufactured with the Resin Transfer Molding (RTM) technique. The test specimens were loaded parallel to the lug centerline. Ten types of specimens, with three kinds of braiding technology (three-dimensional four-directional braiding, three-dimensional five-directional braiding and three-dimensional six-directional braiding), both drilled hole and braided hole, and various dimension, were tested. There are three basic failure modes in braided composite joints: net-tension, shear-out, and bearing. Net-tension failure is associated with matrix and fiber tension failure due to stress concentrations. Shear-out and bearing failures result primarily from the shear and compression failures of fiber and matrix.