断裂力学的工程应用

1552010Vol．15No.52010730070..O346.1A1008－9020（2010）05-031－032010－07－111965—.、..1..1.1、、、、、..1.2、、..1、-a0σc.KIKIC1a.2、-σs.ac1b.13.ac1c.2.2.1KIKI:KI=Yσπa姨KIσ、aY.KIKI.、Y“”.2.2KICKIKIKIC.σc.ac.KIC=Yσcπac姨.σσσσsσsKIC.KIσKICσs、.a0a0a0acacσ-1σcσcσcσscba311552010Vol．15No.520102.3KIKICKI≥KIC.KI＜KIC..3.3.11KIKI、“”.KIσ、a、Y“”.2KIC、.3KI=KICσcac.2.[σ]=980MPaKIC=217MPam姨r=25mma=6mm..2“”KI=fa/rσπa姨fa/r1.1fa/r=1.76KI=KICσc898.3MPa.σc＜[σ].3.2[σ][σ]σsσbnsnb.σsσb.KI=KIC.[σ]=1372MPaa=1mm2c=4mm.σs=2058MPaKIC=46.5MPam姨σs1666MPaKIC77.5MPam姨.KI“”KI=1.1σπα姨Q姨.1.1Q2.2n=σs/[σ]=1.5n=σs/[σ]=1.22．.σ/σs=0.67,a/2c=0.25,2Q1.37KIσc882MPa＜[σ].σ/σs=0.82,a/2c=0.25,2Q1.32KIσc1444.5MPa＞[σ].n=KIC/KI=σc/[σ]=0.64n=KIC/KI=σc/[σ]=1.05..3.3、...dadN=f△K＝C·KnC、n△K△K=△σMa姨Ma/r00.10.20.30.40.50.60.81.01.52.03.05.010.0∞σ-σ-2.392.262.731.982.301.822.041.671.861.581.731.491.641.421.471.321.371.221.181.061.061.010.940.930.810.810.750.750.7070.707σ-σ-3.392.262.731.982.411.832.151.701.961.611.831.571.711.521.581.431.451.381.291.261.211.201.141.131.071.061.031.031.001.00σσσσraa0.10.20.250.30.41.00.881.071.211.381.760.90.911.121.241.411.790.80.951.151.271.451.830.70.981.171.311.481.870.61.021.221.351.521.90＜0.61.101.291.431.601.98a/2cQσ31321552010Vol．15No.52010EngineeringApplicationofFractureMechanicsGULILIUShan-chunXUHong-tongPeiliEngineeringandTechnologySchoolLanzhouCityUniversity,LanzhouGansu730070AbstractBrittledestructionisoneoftheimportantwaysofpartfailurethetraditionalmethodofanti-brittleisveryconservativeorstillproducesbrittlefailure.Fromfracturemechanics,thisarticlediscussedengineeringapplicationsofcrackbody.Keywordsfracturemechanicsstressfieldintensityfactorfracturetoughnesscrackgrowth.KIC、C、na0ac.N=NfN0乙dN=Nf-N0=aca0乙daC·△σnMan2=2n-2C·Mn/2△σn1a0n-22-1acn-2222n≠2=1C·M△σ2Inaca0n=2≠≠≠≠≠≠≠≠≠≠≠≠≠≠≠≠≠≠≠≠≠≠≠≠≠≠≠≠≠≠≠≠≠≠≠≠≠≠≠≠≠≠acKI=KICacac.a0.σ=344.5MPa318℃KIC=71.33MPam姨σs=585.6MPa.a/2c=0.1.dadN=f△K=C·Kn=1.9×10-14△K1.9.40a0.1C=1.9×10-14n=1.9n≠2.2M=1.21πQσ/σs=344.5/585.6=0.588a/2c=0.12Q=1.034M=3.66.3acKI=1.1σπa姨Q姨ac=Q1.21πKIcσ姨姨2=11.7mm4N=46.4×108×11.70.05-a00.053a0NNa03.40146003a0=3.8mm2c=38mm.4..、、、、、、、、、.、、、.、、50%、.[1]．[D]．2003．10.[2]．[D]．2003．10.[3]．[M]．1999．11.33