Given:
Unit square
(
X
1
,
X
2
)
∈
[
0
,
1
]
{\displaystyle (X_{1},X_{2})\in [0,1]}
with displacement fields :
u
=
κ
X
2
e
^
1
+
κ
X
1
e
^
2
{\displaystyle \mathbf {u} =\kappa X_{2}{\widehat {\mathbf {e} }}_{1}+\kappa X_{1}{\widehat {\mathbf {e} }}_{2}}
.
u
=
−
κ
X
2
e
^
1
+
κ
X
1
e
^
2
{\displaystyle \mathbf {u} =-\kappa X_{2}{\widehat {\mathbf {e} }}_{1}+\kappa X_{1}{\widehat {\mathbf {e} }}_{2}}
.
u
=
κ
X
1
2
e
^
2
{\displaystyle \mathbf {u} =\kappa X_{1}^{2}{\widehat {\mathbf {e} }}_{2}}
.
Sketch:
Deformed configuration in
x
1
,
x
2
{\displaystyle x_{1},x_{2}}
plane.
The displacement
u
=
x
−
X
{\displaystyle \mathbf {u} =\mathbf {x} -\mathbf {X} }
. Hence,
x
=
u
+
X
{\displaystyle \mathbf {x} =\mathbf {u} +\mathbf {X} }
. In the reference configuration,
u
=
0
{\displaystyle \mathbf {u} =0}
and
x
=
X
{\displaystyle \mathbf {x} =\mathbf {X} }
. Hence, in the
(
x
1
,
x
2
)
{\displaystyle (x_{1},x_{2})}
plane, the initial square is the same shape as the unit square in the
(
X
1
,
X
2
)
{\displaystyle (X_{1},X_{2})}
plane. We can use Maple to find out the values of
x
1
{\displaystyle x_{1}}
and
x
2
{\displaystyle x_{2}}
after the deformation
u
{\displaystyle \mathbf {u} }
.
with(linalg):</code>
X := array(1..3): x := array(1..3): u = array(1..3):
e1 := array(1..3,[1,0,0]):
e2 := array(1..3,[0,1,0]): e3 = array(1..3,[0,0,1]):
ua := evalm(k*X[2]*e1 + k*X[1]*e2):
ub := evalm(-k*X[2]*e1 + k*X[1]*e2);
uc := evalm(k*X[1]^2*e2);
u
a
:=
[
k
X
2
,
k
X
1
,
0
]
{\displaystyle {\mathit {ua}}:=\left[k{X_{2}},k{X_{1}},0\right]}
u
b
:=
[
−
k
X
2
,
k
X
1
,
0
]
{\displaystyle {\mathit {ub}}:=\left[-k{X_{2}},k{X_{1}},0\right]}
u
c
:=
[
0
,
k
X
1
2
,
0
]
{\displaystyle {\mathit {uc}}:=\left[0,k{X_{1}}^{2},0\right]}
xa := evalm(ua + X);
xb := evalm(ub + X);
xc := evalm(uc + X);</code>
x
a
:=
[
k
X
2
+
X
1
,
k
X
1
+
X
2
,
X
3
]
{\displaystyle {\mathit {xa}}:=\left[k{X_{2}}+{X_{1}},k{X_{1}}+{X_{2}},{X_{3}}\right]}
x
b
:=
[
−
k
X
2
+
X
1
,
k
X
1
+
X
2
,
X
3
]
{\displaystyle {\mathit {xb}}:=\left[-k{X_{2}}+{X_{1}},k{X_{1}}+{X_{2}},{X_{3}}\right]}
x
c
:=
[
X
1
,
k
X
1
2
+
X
2
,
X
3
]
{\displaystyle {\mathit {xc}}:=\left[{X_{1}},k{X_{1}}^{2}+{X_{2}},{X_{3}}\right]}
Plots of the deformed body are shown below
Deformed shapes