基于DCPD的CT试样裂纹扩展数值模拟标定方法

Calibration method for numerical simulation of crack growth of CT specimens based on DCPD

为保证核电结构裂纹扩展监测结果的准确性,建立有效的标定方法至关重要。该文根据直流电位降(DCPD)法的原理和有限元分析软件建立电位场模型,直观、定量地获得电位场变化数据,分析紧凑拉伸(CT)试样在不同裂纹长度下的电位降,并从监测环节考虑多种因素对标定曲线的影响,最后结合裂纹监测平台进行实验验证。结果表明,裂纹主电位接线点的位置、不同材料和几何尺寸对标定曲线产生微伏级的影响,仿真与实验数据分析结果的最大误差为4.9%。该标定曲线具有一定的可行性,可为后续动态裂纹扩展监测实验及验证工作提供参考。

To ensure the accuracy of crack extension monitoring results in nuclear power structures,it is crucial to establish an effective calibration method.This paper establishes an electric potential field model based on the principle of the direct current potential drop(DCPD) method and finite element analysis software to obtain the electric potential field variation data intuitively and quantitatively,analyzes the potential drop of compact tensile(CT) specimens at different crack lengths,and considers the influence of various factors on the calibration curve from the monitoring link,and finally combines the crack monitoring platform for experimental verification.The results show that the location of the crack’s main potential connection point,different materials,and geometric dimensions have microvolt-level effects on the calibration curve,and the maximum error between the simulation and experimental data analysis results is 4.9%.Therefore,the calibration curve has certain feasibility,which provides support for the subsequent dynamic crack extension monitoring experiments and validation work.