NiTi合金動態(tài)斷裂過程的實驗和數(shù)值方法研究
發(fā)布時間:2018-01-23 18:59
本文關(guān)鍵詞: 霍普金森桿 數(shù)值方法 NiTi合金 裂紋擴展計 動態(tài)斷裂過程 出處:《中國測試》2016年10期 論文類型:期刊論文
【摘要】:為獲得Ni Ti合金的動態(tài)起裂韌度和動態(tài)擴展速度與動態(tài)加載率之間的定量變化規(guī)律。利用分離式霍普金森壓桿(SHPB)測試系統(tǒng)對單邊三點彎曲試樣(SENB)進行沖擊加載試驗,采用實驗-有限元相結(jié)合的方法,獲得動態(tài)斷裂參數(shù)隨時間的變化規(guī)律。SENB試樣裂紋起裂時刻和裂紋擴展速度由粘貼在裂紋尖端的裂紋擴展計(CPG)測定。采用上述方法和數(shù)據(jù)獲得Ni Ti合金的I型動態(tài)起裂韌度和動態(tài)擴展速度。實驗結(jié)果表明:裂紋擴展計測得的起裂時刻與粘貼在同一試樣上的監(jiān)裂應(yīng)變片測得的結(jié)果基本相符,因此可以利用裂紋擴展計代替?zhèn)鹘y(tǒng)的監(jiān)裂應(yīng)變片來監(jiān)測裂紋起裂時刻,并獲得Ni Ti合金的起裂韌度。同時,可以利用裂紋擴展計(CPG)獲得裂紋動態(tài)擴展過程,繪制出裂紋擴展速度與時間的關(guān)系曲線,從而探討Ni Ti合金的動態(tài)斷裂韌度和裂紋擴展速度與動態(tài)加載率之間的定量變化規(guī)律。
[Abstract]:In order to obtain the quantitative variation of dynamic crack initiation toughness, dynamic propagation velocity and dynamic loading rate of Ni Ti alloy, the split Hopkinson compression bar SHPBwas used. The impact loading test was carried out on the single-sided three-point bending specimen with a testing system. The method of combining experiment with finite element method is adopted. The variation of dynamic fracture parameters with time is obtained. The crack initiation time and crack growth velocity of SENB specimen are measured by the crack propagating meter (CPG) which is affixed to the crack tip. Measurement. I dynamic initiation toughness and dynamic propagation rate of Ni Ti alloy were obtained by using the above method and data. The experimental results show that:. The crack initiation time measured by crack propagation is basically consistent with that measured by the strain gauge attached to the same specimen. Therefore, the crack initiation time can be monitored by using crack propagator instead of the traditional crack monitoring strain gauge, and the fracture initiation toughness of Ni Ti alloy can be obtained. At the same time, the crack initiation toughness of Ni Ti alloy can be obtained. The crack dynamic growth process can be obtained by using the crack Propagation Meter (CPG), and the curve of the relationship between the crack growth speed and the time can be drawn. The quantitative variation of dynamic fracture toughness, crack growth rate and dynamic loading rate of Ni Ti alloy is discussed.
【作者單位】: 四川大學(xué)建筑與環(huán)境學(xué)院;
【基金】:國家自然科學(xué)委員會與中國工程物理研究院聯(lián)合基金項目(U1430119)
【分類號】:O346.1
【正文快照】: 0引言Ni Ti形狀記憶合金以其獨特的超彈性、形狀記憶性能及良好的生物相容性而備受關(guān)注,目前已廣泛應(yīng)用于醫(yī)療外科、薄膜、航空和微機電等領(lǐng)域[1]。由于形狀記憶合金在工程領(lǐng)域的特殊性,其工作環(huán)境較為惡劣,常遭受碰撞、擠壓等動態(tài)荷載。尤其在航空航天領(lǐng)域,形狀記憶合金構(gòu)件,
本文編號:1458009
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