基于分层理论的螺栓连接夹芯复合材料加筋结构振动特性

针对采用螺栓连接方式固定的夹芯复合材料加筋结构，表层采用分层理论单元、芯层采用体单元，结合有限元方法计算固有频率和振型。通过试验验证，有限元计算结果与试验结果吻合，并得到了在有限元分析中模拟实际结构边界条件的处理方法。试验结果对比表明，与钢制结构相比，夹芯复合材料加筋结构前三阶固有频率提高2倍以上，夹芯复合材料加筋结构能大幅提高整体结构刚度，改善结构的振动特性。 

Vibration characteristics of reinforced sandwich composite structure with bolt connection based on layer-wise theory

The natural frequencies and vibration modes of the bolt fixed sandwich composite structure with stiffeners were obtained using finite element method in while the surface layers were simulated as layerwise elements and the core layers were simulated as solid elements. The simulated results were verified through comparing with experimental results. The method of simulating boundary condition for the actual structure in finite element analysis is obtained. By comparing with the experimental results of steel structure, it is found that the first three-order natural frequencies are twice higher for the sandwich composite reinforced structure. The sandwich composite structure with stiffeners can greatly improve the stiffness of the whole structure and the vibration characteristics of the structure.