含软化带复合材料板的损伤容限特性研究

 碳/环等先进复合材料断裂韧性低,在静载作用下常具有典型的准脆性破坏模式。而在制造和使用中不可避免地会有缺陷、损伤（包括结构缺口等）,致使其承载能力大大降低。为防止损伤突然激发并快速扩展而导致灾难性破坏,软化带设计是一种颇有效果的解决办法。 软化带即在受轴向载荷的板（如机翼翼面）上设置的一些不连续条带。

THE STUDY OF DAMAGE TOLERANCE PROPERTY OF COMPOSITE PLATES WITH SOFTENING STRIPS

This paper presents a special layup concept-----softeningstrip design. The combination of different layups and/or different materials can be used to provide a low-stress and high-toughness region to prevent from crack propagation. Using the concept of softening strip, the potential to improve the damage tolerance of graphite/epoxy laminated composite plates under the action of uniaxial tension is investigated by means of analyses and tests.The specimens were made from 0/ + 45/0]s T300/648 laminates with two pieces of softening-strips (graphite-glass hybrid composite). The effect of crack arrestment and the failure mechanism of the softening strips are studied in the tests through different measure procedures.The ultimate failure load and the load at the onset of rapid crack propagation are tested. In addition, the influence of the crack size and the parameters of the softening strips on the damage tolerance capability are also analysed.The softening strip concept can be used to meet the damage tolerance requirement with less weight penalty.