基于缝隙特征的蜂窝夹层结构刚度损失评估及应用

高精度蜂窝夹层结构反射面板由经过开缝应力释放工艺处理的表层铝板和铝蜂窝芯胶接而成, 为了研究缝隙所引起的夹层结构刚度损失, 基于对实验数据的统计分析, 考虑缝隙面积和分布等对刚度的影响, 定义了缝隙对刚度的影响系数与刚度的损失系数并建立了二者之间的关系, 提出了基于缝隙特征的蜂窝夹层结构刚度损失的评估方法。实验分析结果表明, 缝隙对夹层结构刚度造成的损失达到一定程度后明显减缓, 刚度最大损失可限定在40%。针对表板带有缝隙的夹层结构的数值分析, 依据夹层结构刚度等效原则, 利用刚度损失与缝隙影响系数之间的关系, 可将带有缝隙的表板等效为厚度减薄的连续表板, 对于模拟带有缝隙的夹层结构具有一定的应用价值。

Stiffness loss assessment and application based on fracture features of honeycomb sandwich structure

High precision sandwich reflector panels are made of aluminum face sheet and honeycomb core treated by the gap stress releasing process.In order to study the impact of the gap on sandwich structure stiffness loss,a relationship between the gap influence coefficient considering the influence of the area and distribution of gap on the rigidity and stiffness loss coefficient was established with statistical analysis of tests data.A stiffness loss assessment method based on fracture features of sandwich structure was put forward.The experimental analysis results show that gap will cause stiffness loss,which changes slowly after reaching a certain level and the fracture features influence on the stiffness can be limited into 40%.According to the sandwich structure stiffness equivalent principles and the stiffness loss assessment method,the face sheet with gaps can be replaced by the continuous sheet with decreased thickness during the numerical analysis.It has general application value to simulate the sandwich structure with fracture features.