空心微球/环氧树脂复合泡沫塑料的抗压性能与破坏机制

以环氧树脂为基体, 不同粒径空心玻璃微球为填充体, 制备了轻质高强复合泡沫塑料。通过单轴准静态压缩试验研究了空心微球的粒径大小对复合泡沫塑料的抗压性能的影响, 并采用SEM对复合泡沫塑料的微观结构进行观测。通过随机空间分布法建立了空心玻璃微球/环氧树脂复合泡沫塑料的实体模型, 并且使用有限元分析软件对复合泡沫塑料在1 kPa载荷下的应力分布进行了分析。结果表明, 在相同体积含量下, 当空心微球的粒径从30 μm增大到120 μm时, 复合泡沫塑料的抗压强度无明显变化。有限元分析的结果表明, 在复合泡沫塑料中主要承载部分为空心微球, 空心微球上的应力大于树脂基体上的应力。最大应力分布在空心微球的内壁, 结合SEM图像可推测, 空心微球在破裂之前受到充分的挤压, 并且从内壁产生裂纹。

Compressive property of hollow glass microsphere/epoxy resin syntactic foam and its fracture mechanism

The hollow glass microspheres were sieved to have different particle sizes, and the syntactic foams by blending hollow glass microspheres with epoxy resin were prepared. The compressive mechanical properties of the syntactic foams were studied by quasi-static compressive tests. In addition, the microscopicstructure was observed by SEM. By using the random spatial dispersing method, model of syntactic foams filled with particles having varied particle size were built. And finite element method was utilized to analyze the behavior of the matrix and particles under 1 kPa pressure. The result shows that as the particle diameter of hollow glass microspheres increases from 30 μm to 120 μm, the compressive strength of syntactic foam does not have significant change. With finite element analysis, it is found that hollow glass microspheres are the main energy loader. The value of von-Mises stress located on the hollow microspheres is higher than that of stress located on the matrix. The maximum stress is located on the inner surface of hollow glass microspheres, and it could also infer that microspheres are fully squeezed before crack from inside out with the SEM observation.