Isolarametric Elements

Question 1

Motivation of isoparametric elements

Answer 1

To permit quadrilateral elements to have non rectangular shapes and curved sides

Question 2

Advantages and disadvantages of isoparametric elements

Answer 2

Irregular geometry
Curved boundaries
Transition from coarse to finite mesh to capture stress concentration

Disadvantage: loss of accuracy

Question 3

Requirement for uniqueness

Answer 3

The sign of the Jacobian (determinant), J, remain unchanged at all points of the mapped element