What is EI in Civil Engineering | What is meant by EI constant in a given structure
What is EI in Civil Engineering
EI is the product of the materials modulas of elasticity (E) and the elements second moment of area (I).
- E is a function of how stiff the material is.
- I is a function of the elements shape.
What is meant by EI constant in a given structure
The EI value defines how stiff a structure is.
For example in an EI of the simple concrete beam with width b and depth d, the value of I is equal to b*d^3/12.
The deflection can be calculated as 5/384 * w*length^4 / EI.
In this example, the variables are
- The span of the beam (length),
- The weight that the beam carries (w),
- The beam properties (EI).
The EI constant is often an expression in the engineering world to explain the stiffness of a structural element. E is the Modulus of Elasticity, and I is the second moment of inertia.
EI is most often used in FEM (Finite Element Modeling). This expression is a fundamental building block for analyzing complex structures and is a property for many FEM elements (Beams, Bars, Rods, etc.)
Also Read: Why are I beams shaped like an I?