FracturetestsofOFHCbarsunderimpacttensionandanalysis basedonarepresentativevolumeelement
-
摘要: 采用Hopkinson装置和一种基于一级气体炮的高速冲击拉伸断裂装置,研究了无刻槽高导无氧铜 (OFHC)杆在一系列冲击拉伸速度下的断裂。当冲击拉伸速度大于40m/s时,断裂位置总在冲击拉伸端附 近,此速度被确定为OFHC的实验临界冲击拉伸速度。一种受单轴冲击拉伸荷载的、中心含椭球空穴的样本 体积单元被用于数值模拟所含空穴的增长与失稳的过程。OFHC的J-C与Z-A 本构关系用于描述基体材料 的动态响应。讨论了空穴失稳条件并提出以空穴形状演化为判据,比较了空穴失稳时的样本体积单元平均径 向应变与无刻槽杆的冲击断裂应变。也用这种样本体积单元模型分析了OFHC的实验临界冲击拉伸速度。
-
关键词:
- 固体力学 /
- 单轴冲击拉伸 /
- 样本体积单元\OFHC杆 /
- 断裂实验
Abstract: Unnotchedoxygen-freehighconductive(OFHC)barsweretestedatdifferenttensilevelocitiesonatensionHopkinsonbarandanovelfacilityforhigh- speedtensiletestsbasedonaone-stage gasgunsystem.AndtheimpactvelocitycorrespondingtothefractureattheimpactendwasdeterminedastheexperimentalcriticalimpactvelocityintensionofOFH .Arepresentativevolumeelement( RVE)wasmodeledbyacircularcylindercontaininganellipsoidvoidatitscenterandtheRVE wasdynamicallyloadedbyanaxialvelocityatitstop.Theentireprocesswasnumericallysimulated fromthevoidgrowthtovoidinstabilityintheRVEforOFHCwhichobeyedtheJ-CorZ-Aconstitutiverelation. Theconditionsofdynamicvoidinstabilitywerediscussedandacriterionbasedonvoid shapeevolutionwaspresented.TheaverageradialstrainsoftheRVEinvoidinstabilitywerecomparedwiththeexperimentallocalizedfracturestrainsoftheunnotchedOFHCbarsu deruniaxialimpacttension. TheexperimentalcriticalimpactvelocityintensionofOFHCwasalsoanalyzedbyusing theRVEmodel.-
Key words:
- solid mechanics /
- uniaxialimpacttension /
- representativevolumeelement /
- OFHCbar
期刊类型引用(0)
其他类型引用(3)
-
计量
- 文章访问数: 2383
- HTML全文浏览量: 78
- PDF下载量: 204
- 被引次数: 3