负泊松比结构由于优异的力学特性,逐渐被广泛应用于抗爆炸、抗侵彻等领域。提出了一种基于负泊松比结构的复合结构,从抗侵彻、抗爆炸两个角度设计了三个主要功能层,运用有限元仿真方法探究了异型陶瓷负泊松比复合结构在爆炸环境和弹丸...负泊松比结构由于优异的力学特性,逐渐被广泛应用于抗爆炸、抗侵彻等领域。提出了一种基于负泊松比结构的复合结构,从抗侵彻、抗爆炸两个角度设计了三个主要功能层,运用有限元仿真方法探究了异型陶瓷负泊松比复合结构在爆炸环境和弹丸侵彻下的响应特征,分析了防护机理并设计了参数优化方案,研究了陶瓷层最低厚度、负泊松比结构纵向蜂窝数、内凹六边形凹角、钢板厚度、聚脲层厚度等参数对结构抗爆抗弹性能的影响。通过能量吸收率(Specific Energy Absorption,SEA)、侵彻深度、中心点位移等指标评估不同参数组对应复合结构的防护能力。结果表明,陶瓷层最低厚度是影响结构抗侵彻能力的最大因素,聚脲层厚度和负泊松比结构纵向蜂窝数是影响结构抗爆能力的较大因素。在降低面密度的同时调整各参数,获得了最优抗爆抗侵彻的复合结构设计方案,实现了低面密度与高强防护的结合。研究提供了工程防护增强设计的新思路,助力推进了防护工程轻质化、模块化发展。展开更多
This study proposed an effective plastic deformation technique,rotating backward extrusion(RBE),for producing high performance AZ80 magnesium alloy cup-shaped pieces.The RBE process was carried on the Gleeble-3500 tes...This study proposed an effective plastic deformation technique,rotating backward extrusion(RBE),for producing high performance AZ80 magnesium alloy cup-shaped pieces.The RBE process was carried on the Gleeble-3500 test machine at 653 K,and the conventional backward extrusion(CBE)was also conducted for comparison.A detailed microstructure analysis was performed using the optical microscopy(OM)and electron back-scatter diffraction(EBSD).The results shown that the equivalent strain and deformation uniformity of the cup pieces could be substantially increased by the RBE process compared with the CBE process.Furthermore,the RBE process could significantly improve the grain refining capacity and the proportion of dynamic recrystallization(DRX),of which the maximum reduction of grain size was 88.60%,and the maximum increase of DRX proportion was 55.30%in the cup bottom.The main deformation mechanism of the RBE process was the discontinuous DRX(DDRX),while the continuous DRX(CDRX)was also occurred in the cup transition.Compared with the CBE sample,the texture of the cup bottom was weakened for the RBE sample.The microhardness value of the RBE sample was higher than that of the CBE sample,which can be attributed to the grain refinement strengthening.展开更多
文摘负泊松比结构由于优异的力学特性,逐渐被广泛应用于抗爆炸、抗侵彻等领域。提出了一种基于负泊松比结构的复合结构,从抗侵彻、抗爆炸两个角度设计了三个主要功能层,运用有限元仿真方法探究了异型陶瓷负泊松比复合结构在爆炸环境和弹丸侵彻下的响应特征,分析了防护机理并设计了参数优化方案,研究了陶瓷层最低厚度、负泊松比结构纵向蜂窝数、内凹六边形凹角、钢板厚度、聚脲层厚度等参数对结构抗爆抗弹性能的影响。通过能量吸收率(Specific Energy Absorption,SEA)、侵彻深度、中心点位移等指标评估不同参数组对应复合结构的防护能力。结果表明,陶瓷层最低厚度是影响结构抗侵彻能力的最大因素,聚脲层厚度和负泊松比结构纵向蜂窝数是影响结构抗爆能力的较大因素。在降低面密度的同时调整各参数,获得了最优抗爆抗侵彻的复合结构设计方案,实现了低面密度与高强防护的结合。研究提供了工程防护增强设计的新思路,助力推进了防护工程轻质化、模块化发展。
基金financially supported by the National Natural Science Foundation of China(No.51775520)the National Key Research and Development Program(No.2016YFB0301103-3)+1 种基金the Key R&D program of Shanxi Province(International Cooperation)(No.201903D421036)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(No.2018002)。
文摘This study proposed an effective plastic deformation technique,rotating backward extrusion(RBE),for producing high performance AZ80 magnesium alloy cup-shaped pieces.The RBE process was carried on the Gleeble-3500 test machine at 653 K,and the conventional backward extrusion(CBE)was also conducted for comparison.A detailed microstructure analysis was performed using the optical microscopy(OM)and electron back-scatter diffraction(EBSD).The results shown that the equivalent strain and deformation uniformity of the cup pieces could be substantially increased by the RBE process compared with the CBE process.Furthermore,the RBE process could significantly improve the grain refining capacity and the proportion of dynamic recrystallization(DRX),of which the maximum reduction of grain size was 88.60%,and the maximum increase of DRX proportion was 55.30%in the cup bottom.The main deformation mechanism of the RBE process was the discontinuous DRX(DDRX),while the continuous DRX(CDRX)was also occurred in the cup transition.Compared with the CBE sample,the texture of the cup bottom was weakened for the RBE sample.The microhardness value of the RBE sample was higher than that of the CBE sample,which can be attributed to the grain refinement strengthening.
