

Study with the several resources on Docsity
Earn points by helping other students or get them with a premium plan
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
This assignment solution was submitted to Amar Sharma for Finite Element Method course at Aligarh Muslim University. It includes: Derive, Relationship, Natural, Area, Cartesian, Coordinates, Triangular, Element
Typology: Exercises
1 / 2
This page cannot be seen from the preview
Don't miss anything!


Problem 3.8: Derive the relationship between the natural ( area ) and Cartesian coordinates of a triangular element.
Solution:
The natura l coordinates are given as:
L 1 =
L 2 =
L 3 =
Also
A = A 1 + A 2 + A 3
We have
Also
Ni = L1 Nj = L2 Nk = L 3
Then the relation between the natural and Cartesian coordinates is given by
X = x 1 L 1 + x 2 L 2 + x 3 L 3
Y = y 1 L 1 + y 2 L 2 + y 3 L 3
These equations can be expressed as
This equation can be inverted to obtain
docsity.com
Where A is given as
By expanding, the relation is given as
= L 1 = (x2y3 – x3y2) + (y2 – y3)x + (x3 – x2)y
= L 2 = (x3y1 – x1y3) + (y3 – y1)x + (x1 – x3)y
= L 3 = (x1y2 – x2 y1) + (y1 – y2)x + (x2 – x3)y
docsity.com