摘要
聚脲作为一种涂层或夹层材料被用在爆炸冲击领域,对目标结构具有良好的防护作用。为研究聚脲材料的力学性能,利用万能试验机和分离式霍普金森拉杆试验装置对聚脲材料分别进行准静态和动态拉伸加载试验。得到碳化硅与聚脲纳米复合材料在低应变率(0.001~0.1 s-1)和高应变率(1260~4500 s-1)范围内的真应力-真应变曲线,并分析了应变率强化效应和纳米碳化硅颗粒含量对聚脲力学性能的影响。结合超弹性理论构建了含有应变率效应的准静态和动态本构模型,对试样的模型参数进行了拟合。结果表明:应变率越高,试样的流动应力越大,且动态加载下的流动应力要显著大于准静态,表现出明显的应变率强化效应;碳化硅与聚脲纳米复合材料的力学性能优于纯聚脲材料;碳化硅与聚脲纳米复合材料流动应力与相对应变率的对数在一定应变率范围内基本上满足线性关系;通过对聚脲动态拉伸力学性能数值模拟,仿真结果和试验结果吻合性很好,验证了拉伸试验应力-应变结果的准确性;本构模型拟合结果和试验结果吻合较好,说明所构建的本构模型能够较好地描述碳化硅与聚脲纳米复合材料的力学行为。
Polyurea,as a coating or sandwich material,can be used to improve the protective performance of target structure in the fields of blast and impact.In order to study the tensile mechanical properties and constitutive model of SiC/polyurea nanocomposites,an universal testing machine and split Hopkinson tensile bar(SHTB)apparatus were used in quasi-static and dynamic tests,respectively.The true stress-true strain curves of specimens were obtained in the range of low strain rates(0.001-0.1 s-1)and high strain rates(1260-4500 s-1).The effects of strain rate hardening and nano SiC on the mechanical properties of the specimens were discussed.A constitutive model with strain rate effect was constructed based on the hyperelastic theory.The experimental results show that the higher the strain rate is,the greater the flow stress of specimen is,the test specimens show obvious strain rate effects under dynamic loading,and the mechanical characters are enhanced by adding nano SiC into pure polyurea.The relation between the flow stress and the logarithm of relative strain rate is basically linear.The simulation on the dynamic tensile mechanical properties of polyurea shows that the simulated results are in good agreement with the test results,which verifies the accuracy of the stress-strain results in tensile test.Finally,the fitting results of constitutive model are in good agreement with the test results.This indicates that the constitutive model can better describe the tensile mechanical behavior.
作者
刘强
陈鹏万
苏健军
李芝绒
张玉磊
LIU Qiang;CHEN Pengwan;SU Jianjun;LI Zhirong;ZHANG Yulei(State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081,China;Xi'an Modern Chemistry Research Institute, Xi'an 710065, Shaanxi, China)
出处
《兵工学报》
EI
CAS
CSCD
北大核心
2021年第6期1238-1249,共12页
Acta Armamentarii
基金
国防基础性军工科研院所稳定支持专项项目(WDZCKYXM20190503)
中国兵器四院创新基金项目(SJQC2042)。
关键词
碳化硅
聚脲
纳米复合材料
霍普金森拉杆
拉伸力学性能
应变率
本构模型
SiC
polyurea
nanocomposite
split Hopkinson tensile bar
tensile mechanical property
strain rate
constitutive model
