Question

In the FEM element library, what is the correct name for a three noded triangular element?

(a) Linear strain triangular element

(b) Constant strain triangular element

(c) Variable strain triangular element

(d) Higher-order triangular element

This question was posed to me by my school teacher while I was bunking the class.

The origin of the question is Library of Elements and Interpolation Functions in chapter Interpolation Functions, Numerical Integration and Modelling Considerations of Finite Element Method

Answer 1

Correct answer is (b) Constant strain triangular element

For explanation I would say: A Constant Strain Triangular (CST) element is the simplest triangular element with only three nodes that are located at its ends. A Linear Strain Triangular element (LST) is a six-noded triangular element with three intermediate nodes in addition to three end nodes. For plane stress applications, LST gives an accurate result compare to the three-noded CST element. The variable strain triangular element is a higher-order triangular element with more than six nodes.