本文關(guān)鍵詞：基于J-C模型的鎂合金MB2動靜態(tài)拉伸破壞行為　出處：《爆炸與沖擊》2017年06期 　論文類型：期刊論文

  更多相關(guān)文章： 破壞行為 SHTB實(shí)驗(yàn) 鎂合金MB 應(yīng)力三軸度 應(yīng)變率

【摘要】：為了研究不同應(yīng)力狀態(tài)和應(yīng)變率條件下鎂合金MB2的拉伸破壞行為,利用材料試驗(yàn)機(jī)和分離式Hopkinson拉桿(SHTB),對鎂合金MB2的光滑及缺口圓柱試件進(jìn)行了動靜態(tài)拉伸加載;擬合得到了鎂合金MB2的動靜態(tài)拉伸本構(gòu)關(guān)系,建立了其修正的Johnson-Cook失效破壞準(zhǔn)則,并對不同試件的拉伸破壞行為進(jìn)行了數(shù)值模擬;利用SEM對宏觀破壞模式對應(yīng)的微觀損傷機(jī)理進(jìn)行了分析。結(jié)果表明,隨著應(yīng)力三軸度的增加,鎂合金MB2的等效破壞應(yīng)變先增大后減小,宏觀破壞模式由剪切轉(zhuǎn)為正拉斷,微觀損傷機(jī)制由混合斷裂轉(zhuǎn)變?yōu)轫g窩斷裂;而隨著應(yīng)變率的增加,等效破壞應(yīng)變不斷減小,破壞模式不發(fā)生改變。Johnson-Cook本構(gòu)關(guān)系和修正后的Johnson-Cook失效破壞準(zhǔn)則能較好地?cái)M合動態(tài)靜態(tài)拉伸實(shí)驗(yàn)結(jié)果并預(yù)測不同試件的杯錐形破壞特征。
[Abstract]:In order to study the tensile failure behavior of magnesium alloy MB2 under different stress state and strain rate, the material testing machine and split Hopkinson rod were used. The smooth and notched cylindrical specimens of magnesium alloy MB2 were subjected to static and dynamic tensile loading. The static and static tensile constitutive relation of magnesium alloy MB2 was obtained, the modified Johnson-Cook failure criterion was established, and the tensile failure behavior of different specimens was simulated numerically. The microscopic damage mechanism corresponding to the macroscopic failure mode was analyzed by SEM. The results show that the equivalent failure strain of magnesium alloy MB2 increases first and then decreases with the increase of stress triaxiality. The macroscopic failure mode changed from shear to normal tensile fracture, and the microscopic damage mechanism changed from mixed fracture to dimple fracture. The equivalent failure strain decreases with the increase of strain rate. The failure mode does not change. Johnson-Cook constitutive relation and the modified Johnson-Cook failure failure criterion can fit the dynamic static tensile test results and predict different results. The characteristics of cup cone failure of the specimen.
【作者單位】： 中國工程物理研究院總體工程研究所;
【基金】：國家自然科學(xué)基金項(xiàng)目(11472257) 中國工程物理研究院總體工程研究所創(chuàng)新與發(fā)展基金項(xiàng)目(13CXJ09)
【分類號】：O346
【正文快照】： 鎂合金是一種潛力巨大的輕質(zhì)工程材料,有著廣闊的應(yīng)用前景,其中MB2是鎂合金的典型代表。材料在復(fù)雜應(yīng)力狀態(tài)下的失效破壞行為是工程材料和結(jié)構(gòu)設(shè)計(jì)的理論基礎(chǔ)。目前,鎂合金在動靜態(tài)加載下的力學(xué)行為研究以單向應(yīng)力狀態(tài)為主[1-3],且能實(shí)現(xiàn)復(fù)雜應(yīng)力動態(tài)加載的實(shí)驗(yàn)設(shè)備與技術(shù)尚不

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1 賈東;鎂合金MB2破壞模式與應(yīng)力狀態(tài)的關(guān)系[D];中國工程物理研究院;2013年

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本文編號：1418050