Question

A1 is the first area and N1 is its shape function then shape function N1= ___

(a) A1/A

(b) A-A1

(c) A1+A

(d) A1

This question was posed to me at a job interview.

Question is from Two Dimensional Problems in division Two Dimensional Problems using Constant Strain Triangles of Finite Element Method

Answer 1

The correct answer is (a) A1/A

To explain I would say: The shape functions are physically represented by area co-ordinates. A point in a triangle divides into three areas. The shape functions are precisely represented as

 N1=A1/A .