摘要
采用改进的直接冲击霍普金森杆装置,在高达1100 s^(-1)的应变率荷载作用下对密度梯度泡沫铝进行动态压缩试验研究,在X射线显微断层扫描检测样品的内部结构的基础上,结合数字图像技术记录试样损伤特征。结果表明:正梯度冲击以准矩形应力脉冲实现分层耗能,平均平台应力16.5 MPa,峰值应力较均质材料降低20%;负梯度结构引发应力波反射叠加,初始应力激增至35 MPa。过渡态下试样通过梯度界面的波阻抗匹配实现逐层压溃,冲击态时致密化波协同效应使压缩量提升1.7倍,应变率硬化使动态屈服强度增幅达32%;在132 m/s冲击下切向应变分布由层状分区转变为互穿网络,能量吸收稳定性提升41%,可为设计抗冲击-能量吸收一体化结构提供新范式。
A modified direct impact Hopkinson bar apparatus was used to conduct dynamic compression tests on density gradient aluminum foam under strain rate loads up to 1100 s^(-1).Based on X-ray micro-computed tomography to detect the internal structure of the samples,the damage characteristics of the samples were recorded using digital image correlation(DIC)technology.The results show that the positive gradient impact achieves layered energy dissipation with a quasi-rectangular stress pulse,with an average plateau stress of 16.5 MPa,and the peak stress is reduced by 20%compared to the homogeneous material.The negative gradient structure induces stress wave reflection and superposition,resulting in an initial stress surge to 35 MPa.In the transient state,the sample achieves layer-by-layer crushing through the wave impedance matching of the gradient interface.During the impact state,the densification wave synergistic effect increases the compression amount by 1.7 times,and the strain rate hardening increases the dynamic yield strength by 32%.Under the impact of 132 m/s,the tangential strain distribution changes from laminar partitioning to an interpenetrating network morphology,and the energy absorption stability is improved by 41%,which can provide a new paradigm for designing integrated impact-resistant and energy-absorbing structures.
作者
高航
周丰峻
李锋
梁庆峰
GAO Hang;ZHOU Fengjun;LI Feng;LIANG Qingfeng(Defense Engineering Institute,AMS,PLA)
出处
《防护工程》
2025年第2期6-12,共7页
Protective Engineering
基金
国家自然科学基金青年基金项目(52101172)
关键词
泡沫铝
数字图像技术
冲击响应
破坏模式
aluminum foam
digital image correlation(DIC)
impact response
failure mode
作者简介
第一作者:高航;通信作者:周丰峻
