工业纯钛TA2室温蠕变条件下裂纹尖端的参量表征与估算

Parameter Characterizing and Estimating for Room Temperature Creep Crack Tip of Commercially Pure Titanium TA2

摘要:

通过试验、理论分析和有限元模拟对工业纯钛TA2室温蠕变条件下裂纹尖端应力应变场的参量表征及估算进行了研究。试验研究表明，在室温条件下，工业纯钛TA2存在明显的第1阶段蠕变现象。理论分析和有限元模拟表明，对TA2裂纹体进行保载时，裂纹尖端的应力应变场为HRR场，提出采用与时间相关的J积分来表征，并给出了估算方法。通过有限元计算，获得了TA2室温蠕变条件下CT试样的时间相关J积分值，论证了采用J积分来表征室温蠕变条件下TA2裂纹尖端应力应变场的合理性。将有限元计算与估算方法获得的J积分进行了比较，验证了估算方法的有效性和准确性。

Abstract:

The parameter characterizing and estimating for room temperature creep crack tip stress-strain field of commercially pure titanium TA2 were studied by testing, theoretical analysis and finite element (FE) simulation. Testing results indicate that for commercially pure titanium TA2, the primary creep will occur at room temperature. Theoretical analysis and FE simulation demonstrate that the stress-strain field at the crack tip under loading hold period is HRR field. Thus, the time dependent J-integral was proposed to characterize this HRR field, and an estimation method for the J-integral was provided. Then the FE simulation was used to obtain the time dependent J-integral of TA2 CT specimen under the condition of room temperature creep, which shows that J-integral may appropriately characterize the crack tip stress-stain field. At last, the J-integral obtained by FE simulation and the estimation method were compared, which proves the effectiveness and accuracy of the estimation method.