Stress corrosion cracking (SSC) is another major factor in the life of NPP materials.
![abaqus 6.14 xfem abaqus 6.14 xfem](https://demo.pdfslide.net/img/380x512/reader024/reader/2021010910/5aa80e8f7f8b9aca258b5756/r-1.jpg)
(a) High-cyclic fatigue and (b) low-cyclic fatigue. Most of the time, LCF is the cause of failures, so the LCF is considered in this research.
#Abaqus 6.14 xfem crack
The failure due to the crack propagation in the case of LCF is more prominent as compared to that in case of high-cyclic fatigue (see Figure 1). LCF has two characteristics: plastic deformation in each cycle and low-cycle phenomena. However, LCF is fatigue in which the plastic deformation is considered in each cycle. The mean stress is caused by residual stress, the assembly load, or strongly nonuniform loading. The stress in case of high-cycle fatigue comes from a combination of mean and alternating stresses.
![abaqus 6.14 xfem abaqus 6.14 xfem](https://abaqus-docs.mit.edu/2017/English/SIMA3DXRefImages/xfem-hole-mesh.png)
The fatigue caused by the small elastic strains under a high number of load cycles before failure occurs is called high-cycle fatigue. Resistance to the fatigue by the material can be classified into following regimes: low-cycle fatigue (or short life) or limited resistance ( and cycles), high-cycle fatigue ( cycles), and gigacycle fatigue (more than cycles). After the industrial revolution in the 19 th century, it has become accepted engineering terminology for damage and failure of materials under cyclic loads. The word fatigue was firstly originated from the Latin word Fatigare which means “to tire” and commonly associated with mental and physical weariness in the people. Mechanical fatigue and SCC are two important types of failure in the LWRs. By applying different SCC loads, the overall crack growth is measured as SCC load becomes the main cause of failure in LWRs in some cases particularly in the presence of residual stresses. It has been observed that the separately calculated results for SCC and LCF of crack growth rate are different from those of joint/overall effect. In the case of SCC, (mm/sec) is converted into (mm/cycle), and results are combined at the end. The simulations are carried out using extended finite element method (XFEM) separately, for the SCC and LCF, on an identical crack. As it is an attempt to combine SCC and LCF, this research focuses on the joint effect of SCC and LCF loading on crack propagation. SCC is mainly a combination of the loading, the corrosive medium, and the susceptibility of materials while the LCF depends upon the elements such as compression, moisture, contact, and weld. In the last few decades, many types of research studies have been conducted on these two phenomena separately, but the joint effect of these two mechanisms on the same crack has not been discussed yet though these two loads exist simultaneously in the LWRs. Low-cyclic fatigue (LCF) and stress corrosion cracking (SSC) are the two main causes of failure in light-water reactors (LWRs). The structural integrity analysis of nuclear power plants (NPPs) is an essential procedure since the age of NPPs is increasing constantly while the number of new NPPs is still limited.