Sattar Mohsin, Othman Abdul Rahim, Akhtar Maaz, Kamaruddin Shahrul, Khan Rashid, Masood Faisal, Alam Mohammad Azad, Azeem Mohammad, Mohsin Sumiya
Department of Mechanical Engineering, Universiti Teknologi PETRONAS, Seri Iskandar 32610, Perak, Malaysia.
Department of Mechanical Engineering, NED University of Engineering & Technology, Karachi 75270, Sindh, Pakistan.
Materials (Basel). 2021 Sep 23;14(19):5518. doi: 10.3390/ma14195518.
In a number of circumstances, the Kachanov-Rabotnov isotropic creep damage constitutive model has been utilized to assess the creep deformation of high-temperature components. Secondary creep behavior is usually studied using analytical methods, whereas tertiary creep damage constants are determined by the combination of experiments and numerical optimization. To obtain the tertiary creep damage constants, these methods necessitate extensive computational effort and time to determine the tertiary creep damage constants. In this study, a curve-fitting technique was proposed for applying the Kachanov-Rabotnov model into the built-in Norton-Bailey model in Abaqus. It extrapolates the creep behaviour by fitting the Kachanov-Rabotnov model to the limited creep data obtained from the Omega-Norton-Bailey regression model and then simulates beyond the available data points. Through the Omega creep model, several creep strain rates for SS-316 were calculated using API-579/ASME FFS-1 standards. These are dependent on the type of the material, the flow stress, and the temperature. In the present work, FEA creep assessment was carried out on the SS-316 dog bone specimen, which was used as a material coupon to forecast time-dependent permanent plastic deformation as well as creep behavior at elevated temperatures and under uniform stress. The model was validated with the help of published experimental creep test data, and data optimization for sensitivity study was conducted by applying response surface methodology (RSM) and ANOVA techniques. The results showed that the specimen underwent secondary creep deformation for most of the analysis period. Hence, the method is useful in predicting the complete creep behavior of the material and in generating a creep curve.
在许多情况下，Kachanov-Rabotnov各向同性蠕变损伤本构模型已被用于评估高温部件的蠕变变形。二次蠕变行为通常采用解析方法进行研究，而三次蠕变损伤常数则通过实验和数值优化相结合的方式来确定。为了获得三次蠕变损伤常数，这些方法需要大量的计算工作和时间来确定三次蠕变损伤常数。在本研究中，提出了一种曲线拟合技术，用于将Kachanov-Rabotnov模型应用于Abaqus中的内置Norton-Bailey模型。它通过将Kachanov-Rabotnov模型拟合到从Omega-Norton-Bailey回归模型获得的有限蠕变数据来推断蠕变行为，然后在可用数据点之外进行模拟。通过Omega蠕变模型，使用API-579/ASME FFS-1标准计算了SS-316的几种蠕变应变速率。这些取决于材料的类型、流动应力和温度。在当前工作中，对SS-316狗骨试样进行了有限元分析蠕变评估，该试样用作材料试样，以预测随时间变化的永久塑性变形以及高温和均匀应力下的蠕变行为。该模型借助已发表的实验蠕变测试数据进行了验证，并通过应用响应面方法（RSM）和方差分析（ANOVA）技术进行了敏感性研究的数据优化。结果表明，在大部分分析期间，试样经历了二次蠕变变形。因此，该方法可用于预测材料的完整蠕变行为并生成蠕变曲线。
