Shape function in Finite Element Method
Clash Royale CLAN TAG#URR8PPP
up vote
-1
down vote
favorite
Why is it that the choice of polynomial for 6-nodes rectangular element(linear in sides 1 and 3, quadratic in sides 2 and 4) in FEM does not follow normal pascal triangle regular arrangement? i.e $u=c_1+c_2x+c_3y+c_4xy+c_5xy^2+c_6x^2y$ .
finite-element-method
add a comment |Â
up vote
-1
down vote
favorite
Why is it that the choice of polynomial for 6-nodes rectangular element(linear in sides 1 and 3, quadratic in sides 2 and 4) in FEM does not follow normal pascal triangle regular arrangement? i.e $u=c_1+c_2x+c_3y+c_4xy+c_5xy^2+c_6x^2y$ .
finite-element-method
2
Welcome to MSE. For some basic information about writing mathematics at this site see, e.g., basic help on mathjax notation, mathjax tutorial and quick reference, main meta site math tutorial and equation editing how-to.
â José Carlos Santos
Sep 5 at 10:37
add a comment |Â
up vote
-1
down vote
favorite
up vote
-1
down vote
favorite
Why is it that the choice of polynomial for 6-nodes rectangular element(linear in sides 1 and 3, quadratic in sides 2 and 4) in FEM does not follow normal pascal triangle regular arrangement? i.e $u=c_1+c_2x+c_3y+c_4xy+c_5xy^2+c_6x^2y$ .
finite-element-method
Why is it that the choice of polynomial for 6-nodes rectangular element(linear in sides 1 and 3, quadratic in sides 2 and 4) in FEM does not follow normal pascal triangle regular arrangement? i.e $u=c_1+c_2x+c_3y+c_4xy+c_5xy^2+c_6x^2y$ .
finite-element-method
finite-element-method
edited Sep 8 at 17:23
Han de Bruijn
12k22260
12k22260
asked Sep 5 at 10:32
COLLINS AKEREMALE
1
1
2
Welcome to MSE. For some basic information about writing mathematics at this site see, e.g., basic help on mathjax notation, mathjax tutorial and quick reference, main meta site math tutorial and equation editing how-to.
â José Carlos Santos
Sep 5 at 10:37
add a comment |Â
2
Welcome to MSE. For some basic information about writing mathematics at this site see, e.g., basic help on mathjax notation, mathjax tutorial and quick reference, main meta site math tutorial and equation editing how-to.
â José Carlos Santos
Sep 5 at 10:37
2
2
Welcome to MSE. For some basic information about writing mathematics at this site see, e.g., basic help on mathjax notation, mathjax tutorial and quick reference, main meta site math tutorial and equation editing how-to.
â José Carlos Santos
Sep 5 at 10:37
Welcome to MSE. For some basic information about writing mathematics at this site see, e.g., basic help on mathjax notation, mathjax tutorial and quick reference, main meta site math tutorial and equation editing how-to.
â José Carlos Santos
Sep 5 at 10:37
add a comment |Â
1 Answer
1
active
oldest
votes
up vote
0
down vote
See above picture: there are only (linear) line segments in vertical direction.
And because of the three nodal points, there are two quadratic elements in horizontal direction. A reference for the latter:
- Understand 1D FEM solution using quadratics elements
Therefore the interpolation must be linear in $,y,$ and quadratic in $,x,$. According to a Cartesian product:
$$
(1,y) times (1,x,x^2) = (1,x,x^2,y,yx,yx^2)
$$
Mind that your term with $y^2$ is absent now and two terms with $x^2$ are present.
So the correct interpolation may be formulated as:
$$
u=c_1+c_2x+c_3y+c_4xy+colorredc_5x^2+c_6x^2y
$$
add a comment |Â
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
0
down vote
See above picture: there are only (linear) line segments in vertical direction.
And because of the three nodal points, there are two quadratic elements in horizontal direction. A reference for the latter:
- Understand 1D FEM solution using quadratics elements
Therefore the interpolation must be linear in $,y,$ and quadratic in $,x,$. According to a Cartesian product:
$$
(1,y) times (1,x,x^2) = (1,x,x^2,y,yx,yx^2)
$$
Mind that your term with $y^2$ is absent now and two terms with $x^2$ are present.
So the correct interpolation may be formulated as:
$$
u=c_1+c_2x+c_3y+c_4xy+colorredc_5x^2+c_6x^2y
$$
add a comment |Â
up vote
0
down vote
See above picture: there are only (linear) line segments in vertical direction.
And because of the three nodal points, there are two quadratic elements in horizontal direction. A reference for the latter:
- Understand 1D FEM solution using quadratics elements
Therefore the interpolation must be linear in $,y,$ and quadratic in $,x,$. According to a Cartesian product:
$$
(1,y) times (1,x,x^2) = (1,x,x^2,y,yx,yx^2)
$$
Mind that your term with $y^2$ is absent now and two terms with $x^2$ are present.
So the correct interpolation may be formulated as:
$$
u=c_1+c_2x+c_3y+c_4xy+colorredc_5x^2+c_6x^2y
$$
add a comment |Â
up vote
0
down vote
up vote
0
down vote
See above picture: there are only (linear) line segments in vertical direction.
And because of the three nodal points, there are two quadratic elements in horizontal direction. A reference for the latter:
- Understand 1D FEM solution using quadratics elements
Therefore the interpolation must be linear in $,y,$ and quadratic in $,x,$. According to a Cartesian product:
$$
(1,y) times (1,x,x^2) = (1,x,x^2,y,yx,yx^2)
$$
Mind that your term with $y^2$ is absent now and two terms with $x^2$ are present.
So the correct interpolation may be formulated as:
$$
u=c_1+c_2x+c_3y+c_4xy+colorredc_5x^2+c_6x^2y
$$
See above picture: there are only (linear) line segments in vertical direction.
And because of the three nodal points, there are two quadratic elements in horizontal direction. A reference for the latter:
- Understand 1D FEM solution using quadratics elements
Therefore the interpolation must be linear in $,y,$ and quadratic in $,x,$. According to a Cartesian product:
$$
(1,y) times (1,x,x^2) = (1,x,x^2,y,yx,yx^2)
$$
Mind that your term with $y^2$ is absent now and two terms with $x^2$ are present.
So the correct interpolation may be formulated as:
$$
u=c_1+c_2x+c_3y+c_4xy+colorredc_5x^2+c_6x^2y
$$
answered Sep 8 at 18:20
Han de Bruijn
12k22260
12k22260
add a comment |Â
add a comment |Â
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f2906115%2fshape-function-in-finite-element-method%23new-answer', 'question_page');
);
Post as a guest
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
2
Welcome to MSE. For some basic information about writing mathematics at this site see, e.g., basic help on mathjax notation, mathjax tutorial and quick reference, main meta site math tutorial and equation editing how-to.
â José Carlos Santos
Sep 5 at 10:37