FGM materials in Abaqus

In the field of materials science, Functionally Graded Materials (FGMs) are defined by their gradual changes in composition and structure throughout their volume, which leads to corresponding variations in their properties. These materials can be engineered to serve particular functions and meet specific requirements for various applications. FGM materials can have different properties such as mechanical strength, thermal conductivity, electrical conductivity, and corrosion resistance, among others. The variation in properties is typically achieved by gradually changing the composition, microstructure, or both, of the material across its structure.

FGM materials are used in various applications such as aerospace, biomedical, energy, and automotive industries. For example, in aerospace, FGM materials can be used in turbine blades to improve their resistance to high temperatures and mechanical stress. In biomedical applications, FGM materials can be used to create implants that have better biocompatibility with the body tissues. An essential feature of functionally graded materials is their capacity to impede the spread of cracks, which renders them valuable as protective materials in defense applications such as armor plates and bulletproof vests.

For FGM modeling in Abaqus, there are three methods:

1. You can use UMAT or USDFLD subroutine to model the material and its properties, which is a precise and good method but it’s difficult because you have to deal with coding.
2. In the second method, you must divide the part into several layers and assign the material properties of each layer according to the given law. This is comparable to approximating a continuous function with a function that is constant in pieces. The more layers are used, the more accurate the approximation becomes. By increasing the number of layers, the convergence of the process can be analyzed.
3. The third method is easier and also have a good precision. In this method you must use the temperature-dependent data option in the edit material window and use it as a length or thickness of the part. This method involves assigning a temperature that varies continuously across the thickness of the material, which is then used to establish a direct relationship between temperature and mechanical properties. By correlating the distribution of temperature and mechanical properties, it becomes possible to vary the mechanical properties of the FGM material throughout the thickness of the part. It should be noted that this analysis is focused solely on the mechanical properties of the material, and does not take into account factors such as thermal conductivity or other thermal parameters, which are assumed to be zero. A key advantage of this technique is that it eliminates the need to divide the thick wall of the material into multiple thin layers.