(1. 北京科技大學(xué) 材料科學(xué)與工程學(xué)院，北京 100083；
2. 中國兵器裝備集團公司 西南技術(shù)工程研究所，重慶 400039)
摘 要: 利用Gleeble1500熱模擬試驗機和分離式霍普金森壓桿試驗裝置(SHPB)對T2銅進行常溫下準(zhǔn)靜態(tài)壓縮試驗和高應(yīng)變率下的沖擊壓縮實驗, 獲得不同應(yīng)變率下的應(yīng)力-應(yīng)變曲線。結(jié)果表明:T2銅在動態(tài)沖擊下的強度明顯高于準(zhǔn)靜態(tài)壓縮下的強度，具有顯著的應(yīng)變率強化效應(yīng)；在動態(tài)沖擊較低應(yīng)變速率的區(qū)域內(nèi)，T2銅的塑性流動應(yīng)力對應(yīng)變率很敏感，具有明顯的應(yīng)變強化和應(yīng)變率強化效應(yīng)。但在動態(tài)沖擊較高應(yīng)變速率的區(qū)域內(nèi)，發(fā)生相同變形時的應(yīng)力水平相差不大，表現(xiàn)出對應(yīng)變率變化不敏感的性質(zhì)。對傳統(tǒng)的Johnson-Cook本構(gòu)模型進行修正，擬合曲線與試驗曲線吻合較好。
關(guān)鍵字: T2銅；霍普金森壓桿試驗；應(yīng)變率效應(yīng)；本構(gòu)模型
（1.School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China;
2. Southwest Technology and Engineering Research Institute,
China South Industries Group Corporation, Chongqing 400039, China）
Abstract:The quasi-static compression and impact experiment under high strain rates of the T2 copper were carried out at room temperature by the Gleeble1500 thermal simulation testing machine and high split Hopkison pressure bar (SHPB) testing technique. The stress-strain curves of materials at different strain rates were obtained. The experimental results show that the strength of T2 copper under dynamic impact is obviously higher than that under quasi-static compression and the strain rate strengthening effect is significant. In the lower strain rate region of the dynamic impact, the plastic flow stress of T2 copper is very sensitive to strain rate, and it has obvious strain hardening and strain rate hardening effect. But in the higher strain rate region of the dynamic impact, the stresses under the same strain are not quite different and they are not sensitive to strain rates. The traditional Johnson-Cook constitutive model is modified to make the fitting curves agree well with the test curves.
Key words: T2 copper; split Hopkison pressure bar test; strain rate effect; constitutive model
