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针对缠绕复合材料交叉起伏区域的细观结构,建立了一种细观分析模型。首先,将纤维交叉起伏区域划分为环向交叉起伏区和螺旋交叉起伏区2种类型;然后,以缠绕面为基准,用平行横截面将起伏区域空间结构模型离散化为多个子模型,运用纤维束起伏角、富树脂区域尺寸、纤维束的体积分数、纤维束的横截面形状及尺寸等细观参数来描述缠绕复合材料交叉起伏区域的细观结构。基于所建立的细观模型及层合板理论,提出了缠绕复合材料交叉起伏区域的等效刚度计算方法。通过算例研究了纤维束截面、纤维束起伏角以及富树脂区体积分数等细观参数对局部区域等效刚度的影响。结果表明:环向交叉起伏区的弹性模量比螺旋交叉起伏区下降得更为明显;在富树脂区域,弹性模量和剪切模量降低较为明显,而泊松比则有所增大。纤维束厚度增加及纤维束截面变化对交叉起伏区域等效刚度会产生明显影响。
Aiming at the mesostructure of the cross-sectional area of the wound composite material, a mesoscopic analysis model was established. First of all, the cross-sectional area of the fiber is divided into two types of cross-undulating area and spiral cross-hatching area. Then, based on the winding surface, the spatial cross-section of the undulating area is discretized into several sub-models. The microscopic structure of the cross-sectional area of the entangled composite was described by using the mesoscopic parameters such as the beam buoyancy angle, the area of the resin-rich zone, the volume fraction of the fiber bundle, the cross-sectional shape and the size of the fiber bundle. Based on the established meso-model and the theory of laminate, the equivalent stiffness calculation method of the cross-sectional area of the wound composite was proposed. The influences of the mesoscopic parameters such as fiber bundle cross section, fiber bundle buoyancy angle and resin-rich volume fraction on the equivalent stiffness of the local area are studied by numerical examples. The results show that the elastic modulus of the circumferentially crossed zone is more obvious than that of the spiral cross-sectional area. In the resin-rich zone, the elastic modulus and shear modulus decrease obviously, while the Poisson’s ratio increases. The increase of fiber bundle thickness and the change of fiber bundle cross section have a significant effect on the equivalent stiffness of the cross-wale area.