Multi-point impact behavior and the relationship between CAI strength and DBIP of PMI foam sandwich structures  

作　　者：Keyu ZHU Xitao ZHENG Jiaming SUN Guoyue WANG Leilei YAN 

机构地区：[1]School of Aeronautics,Northwestern Polytechnical University,Xi’an 710072,China

出　　处：《Chinese Journal of Aeronautics》2024年第10期265-274,共10页中国航空学报（英文版）

基　　金：Supported by the National Key R&D Program of China(2023YFB3709602,2023YFB3709603);National Natural Science Foundation of China(12372141);the Key R&D Program in Shaanxi Province(2024GH-ZDXM-27).

摘　　要：Sandwich structures are vulnerable to multi-point impacts,and such impacts can result in a reduction in residual strength even catastrophic accident.Therefore,the multi-point impact behaviors of PMI foam sandwich structure are investigated and studied using experimental and numerical coupled methods.Three impact energy levels and five Distances Between Impact Positions(DBIP)are considered in details,and representative impact characteristics are compared to reveal the association between Compression After Impact(CAI)strength and DBIP.Results indicate that the interference between the multi-point impact events has a dominant effect on CAI strength when DBIP is small,and the variation in bending stiffness induced by the boundary effect is the dominant factor affecting CAI strength when DBIP ranges from 20 mm to 60 mm.In addition,matrix damage represents the primary damage mode in multi-point impact,and the calculated ratio of energy absorbed by the top face sheet and honeycomb core,in relation to the total absorbed energy,serves as a clear indicator of the damage severity experienced by both components.This work is enlightening for the structural design of impact-resistant composites.

关 键 词：Multi-point impact Damage mechanism Interference effect CAI strength Numerical method 

分 类 号：V214.8[航空宇航科学与技术—航空宇航推进理论与工程]