# A Comparative Analysis of 3D Software for Modeling Fatigue Crack Growth: A Review
## 2 Software
### Numerical-Based Approaches
#### 2.1.5. Fmfat  
FEMFAT is a widely used software package in the automotive and mechanical engineering industries, offering a wide range of capabilities for fatigue life analysis [60; 61]. It supports both high-cycle and low-cycle fatigue analyses and allows for the assessment of multiaxial loading, mean stress, and variable amplitude loading effects on fatigue life predictions. With its comprehensive material database, FEMFAT simplifies the selection and assignment of fatigue material properties for different engineering materials.  
FEMFAT offers numerous benefits when it comes to fatigue crack growth simulation. These advantages can be summarized as follows:  
* The software seamlessly integrates with popular finite element analysis (FEA) software packages like ANSYS, ABAQUS, and MSC Nastran, enabling effortless transfer of geometry, mesh, and loading conditions [62; 63; 64]. This integration streamlines the analysis workflow and enhances the accuracy of fatigue life predictions. FEMFAT can directly import the geometry of the component or structure from the FEA software, eliminating the need for manual reconstruction and ensuring consistency. It can also import the mesh, including element connectivity and nodal coordinates, preserving structural details.
* FEMFAT accesses the loading conditions from the FEA software, such as forces or displacements, which are crucial for fatigue analysis. Additionally, it retrieves the results of the FEA analysis, like stress distribution and strain data, to facilitate realistic and accurate fatigue life assessment [65; 66; 67].
* FEMFAT offers a range of analysis options that are suitable for both metallic and non-metallic components. It allows for the simultaneous analysis of base materials as well as welded and/or spot joints. Additionally, FEMFAT incorporates the effects of different manufacturing processes on the fatigue behavior of components. It specifically considers processes such as shot peening, rolling, carburizing, and nitriding, as they have a significant impact on the component's fatigue properties [68].
* FEMFAT provides a unified framework for modeling fatigue crack growth. It covers the entire fracture evolution, including nucleation, propagation, branching, and kinking [69].
* FEMFAT takes into account the influence of residual stress distribution near the crack tip. This consideration enhances the accuracy of fatigue life predictions [70].  
While FEMFAT is indeed a powerful tool for fatigue analysis, it is important to be aware of certain limitations associated with its application. Here are some limitations to consider when using FEMFAT for fatigue analysis:* Limited to Low-Cycle Fatigue: FEMFAT is primarily designed for low-cycle fatigue analysis, which is typically applicable to components subjected to high loads and a relatively small number of stress cycles. It may not be as effective in analyzing high-cycle fatigue or very long-life situations [71; 72].
* Lack of Environmental Effects: FEMFAT primarily focuses on mechanical loading and fatigue behavior. It does not account for environmental factors, such as temperature, humidity, or corrosive conditions, which can significantly affect fatigue life.
* FEMFAT may encounter issues when all element nodes are declared as weld nodes at a shell element. This can lead to interpretation errors and overly conservative results for certain stress conditions.
* FEMFAT ignores stresses in elements other than weld elements connected to a simple weld node. Proper modeling guidelines should be followed to avoid this issue [73; 74].