All components of the structural model have material - the substance from which something is made. Commonly used are:
- Metals
- Wood
- Concrete
- Plastics
The choice of material would depend on the component's purpose. For example, a steel beam might work if this member supports a floor.
Material Properties
Homogeneous and Heterogeneous Materials
Homogeneous and heterogeneous have something to do with "how consistent something is." When someone says the former, its properties are uniform throughout; otherwise, it is the latter.
This property depends on the position. Let's look at a steel beam.
When we analyze any point, we expect it to look the same greyish metal. We can say it is homogeneous.
On a side note, this property depends on scale. Let's go back to our steel beam example.
If we investigate its microstructure, one may find flaky fragments, such as iron and carbon; At this scale, steel is heterogeneous.
Anisotropic and Isotropic Materials
Scientists have discovered that properties depend on direction. When properties change along a path, it is anisotropic. On the other hand, when properties remain the same, it is isotropic. Let's look at examples:
A great example of the former is wood. Its strength perpendicular to the grain differs from its strength parallel to it. On a side note, wood is also orthotropic - the properties change when analyzed along orthogonal axes.
For the latter, steel is a good example. The strength is the same no matter what direction we analyze.
It is important to note that this property also depends on scale.
Composite Materials
We can combine objects of different substances to form composites. For these materials, properties change. Generally, we do this for several reasons, such as to increase strength and stiffness.
Summary
Materials such as metals, wood, concrete, and plastics make a structure.
Homogeneous are those whose properties are the same at any point while heterogeneous are those that vary. It will depend on position and scale.
Anisotropic are those whose properties change in path. Isotropic are those that stay the same. These properties will depend on scale.
Composite materials occur when two or more materials act together.
