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·1592· 工程科学学报,第37卷,第12期 0.5 0 -0.5 ◆ 13 1.4 1.5 1.6 1.7 1.3 1.4 1.5 1.6 △K/(MPa-m-吗 △K/MPa·m-13 图7Q345R疲劳裂纹扩展过程声发射计数率(a)和声发射能量率(b)与△K的关系 Fig.7 Relations of acoustic emission count rate (a)and acoustic emission energy rate (b)to AK for Q345R 数计算的疲劳裂纹长度,计算结果偏于保守,但对于工 程测量而言,声发射监测技术是预测构件疲劳裂纹和 3结论 剩余寿命的有效方法 (1)Q345R疲劳裂纹扩展的声发射过程分为三个 1.6m 明显的阶段,分别对应疲劳裂纹扩展的近门槛扩展区、 --da/dN-dC/dN 1.2 da/dN-dE/dN 稳态扩展区和失稳断裂区.累积计数值和累积能量值 0.8 可以很好地表征整个疲劳裂纹扩展过程 (2)声发射参数在第2阶段到第3阶段的转折点 0.4 NP/DE 比线弹性断裂力学定义下的要提前,这表明声发射技 0 术对疲劳进入失稳扩展阶段更加敏感. (3)建立了低合金钢Q345R声发射计数率和能 0.4 量率与疲劳裂纹扩展速率的关系,可以为Q345R剩余 0.8 寿命的预测提供依据 -12 08 04 0 0.4 0.8 dC/dN.dE/dN 参考文献 图8da/dW与dC/dW以及da/dW与dE/dW的关系 [Smith T A,Warwick R G.A survey of defects in pressure vessel Fig.8 da/dN rs.dC/dN and da/dN rs.dE/dN built to high standard of construction.Int I Pressure Vessels Piping,1974,2(4):283 1 Shen G T,Zhang W L.A review of nondestructive testing tech- 32 0 一一计数计算的裂纹 niques for pressure vessels.Nondestr Test.2004,26(1):37 28 ·一能量计算的裂纹 (沈功田,张万岭.压力容器无损检测技术综述.无损检测, ■实测裂纹 24 2004,26(1):37) 2 [3] Shen GT,Li JH.Nondestructive inspection of pressure vessels: 20 g18 acoustic emission technique.Nondestr Test,2004,26(9):457 16 (沈功田,李金海.压力容器无损检测:声发射检测技术。无 4 12 损检测,2004,26(9):457) 10 [4] Roberts T,Talebzadeh M.Acoustic emission monitoring of fatigue 8 crack propagation.J Constr Steel Res,2003,59(6):695 特接和 [5] Han Z Y,Luo H Y,Zhang Y B,et al.Effects of micro-structure 00 on fatigue crack propagation and acoustic emission behaviors in a 20000400006000080000100000120000140000 micro-alloyed steel.Mater Sci Eng A,2013,559:534 循环次数 [6]Han Z Y,Luo H Y,Cao J W,et al.Acoustic emission during fa- 图90345R疲劳裂纹扩展长度的计算值与实测值对比 tigue crack propagation in a micro-alloyed steel and welds.Mater Fig.9 Comparison between calculated crack length by acoustic emis- Sei Eng A,2011,528(2526):7751 sion and measured crack length 7]Kohn D,Ducheyne P,Awerbuch P.Acoustic emission during工程科学学报,第 37 卷,第 12 期 图 7 Q345R 疲劳裂纹扩展过程声发射计数率( a) 和声发射能量率( b) 与 ΔK 的关系 Fig. 7 Relations of acoustic emission count rate ( a) and acoustic emission energy rate ( b) to ΔK for Q345R 数计算的疲劳裂纹长度,计算结果偏于保守,但对于工 程测量而言,声发射监测技术是预测构件疲劳裂纹和 剩余寿命的有效方法[14]. 图 8 da / dN 与 dC/ dN 以及 da /dN 与 dE/dN 的关系 Fig. 8 da / dN vs. dC/ dN and da / dN vs. dE/ dN 图 9 Q345R 疲劳裂纹扩展长度的计算值与实测值对比 Fig. 9 Comparison between calculated crack length by acoustic emis￾sion and measured crack length 3 结论 ( 1) Q345R 疲劳裂纹扩展的声发射过程分为三个 明显的阶段,分别对应疲劳裂纹扩展的近门槛扩展区、 稳态扩展区和失稳断裂区. 累积计数值和累积能量值 可以很好地表征整个疲劳裂纹扩展过程. ( 2) 声发射参数在第 2 阶段到第 3 阶段的转折点 比线弹性断裂力学定义下的要提前,这表明声发射技 术对疲劳进入失稳扩展阶段更加敏感. ( 3) 建立了低合金钢 Q345R 声发射计数率和能 量率与疲劳裂纹扩展速率的关系,可以为 Q345R 剩余 寿命的预测提供依据. 参 考 文 献 [1] Smith T A,Warwick R G. A survey of defects in pressure vessel built to high standard of construction. Int J Pressure Vessels Piping,1974,2( 4) : 283 [2] Shen G T,Zhang W L. A review of nondestructive testing tech￾niques for pressure vessels. Nondestr Test,2004,26( 1) : 37 ( 沈功田,张万岭. 压力容器无损检测技术综述. 无损检测, 2004,26( 1) : 37) [3] Shen G T,Li J H. Nondestructive inspection of pressure vessels: acoustic emission technique. Nondestr Test,2004,26( 9) : 457 ( 沈功田,李金海. 压力容器无损检测: 声发射检测技术. 无 损检测,2004,26( 9) : 457) [4] Roberts T,Talebzadeh M. Acoustic emission monitoring of fatigue crack propagation. J Constr Steel Res,2003,59( 6) : 695 [5] Han Z Y,Luo H Y,Zhang Y B,et al. Effects of micro-structure on fatigue crack propagation and acoustic emission behaviors in a micro-alloyed steel. Mater Sci Eng A,2013,559: 534 [6] Han Z Y,Luo H Y,Cao J W,et al. Acoustic emission during fa￾tigue crack propagation in a micro-alloyed steel and welds. Mater Sci Eng A,2011,528( 25-26) : 7751 [7] Kohn D,Ducheyne P,Awerbuch P. Acoustic emission during · 2951 ·
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