Question

In FEM, which option is not correct with respect to the generation of element geometries?

(a) It involves coordinate transformation

(b) It is based on a one-to-many mapping

(c) A point in actual element maps uniquely to master element

(d) Tiny interior angles are avoided

This question was addressed to me in an internship interview.

I'd like to ask this question from Modelling Considerations topic in section Interpolation Functions, Numerical Integration and Modelling Considerations of Finite Element Method

Answer 1

The correct choice is (b) It is based on a one-to-many mapping

The best I can explain: The numerical evaluation of integrals over actual elements involves a coordinate transformation from the actual element to a master element. The transformation is acceptable if and only if every point in the actual element is mapped uniquely into a point in the master element, and vice versa. Such mappings are termed one-to-one. To avoid numerical failure of matrices, the interior angle at each vertex of a triangular element should be reasonably larger than 0°.