ema 405 quadrilateral elements. introduction quadrilateral elements are 4-sided, planar elements...
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![Page 1: EMA 405 Quadrilateral Elements. Introduction Quadrilateral elements are 4-sided, planar elements They can address plane stress, plane strain, or axisymmetric](https://reader035.vdocuments.site/reader035/viewer/2022071709/56649d015503460f949d3eaf/html5/thumbnails/1.jpg)
EMA 405Quadrilateral Elements
![Page 2: EMA 405 Quadrilateral Elements. Introduction Quadrilateral elements are 4-sided, planar elements They can address plane stress, plane strain, or axisymmetric](https://reader035.vdocuments.site/reader035/viewer/2022071709/56649d015503460f949d3eaf/html5/thumbnails/2.jpg)
IntroductionQuadrilateral elements are 4-sided,
planar elementsThey can address plane stress, plane
strain, or axisymmetric analyses◦Plane stress - z=0 (for thin structures)
◦Plane strain - z=0 (for thick structures)
◦Axisymmetric will be addressed in the next chapter
2-D triangular elements are related and can be thought of as quad elements where two nodes are coincident
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Element Types in ANSYSConstant Strain TriangleOption for Plane42 in ANSYS
3
2
1
53
6
2
654
321
),(
),(
cc
c
c
ycxccyxv
ycxccyxu
xy
y
x
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What if triangles have midside nodes (linear strain triangle)?
3
45
26
1
ycxccycxcc
ycxcc
ycxcc
ycxycxcycxccyxv
ycxycxcycxccyxu
xy
y
x
11108653
12119
542
12112
10987
265
24321
22
2
2
),(
),(2
Plane2 element in ANSYS
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Bilinear quadrilateral element?
3
4
21yccxcc
xcc
ycc
xycycxccyxv
xycycxccyxu
xy
y
x
8643
87
42
8765
4321
),(
),(
Option in Plane42 element in ANSYS
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Bilinear Quadrilateral (cont.)
This element does not permit curvature in bending
this
not this
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Quadratic quadrilateral element?
3
4
21
287542
216
215
21413
21211109
28
27
265
24321
22
),(
),(
ycxycycxcxc
xycyxcycxycxcycxccyxv
xycyxcycxycxcycxccyxu
x
Plane82 element in ANSYS
7
6
5
8
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Improved bilinear quadrilateral elementThis is the default behavior of
Plane42 in ANSYSIt adds curvature terms to the
assumed displacements to permit curvature in bending
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Von Mises Stress
Also known as equivalent stressA common model for the onset of
yielding in multiaxial stress states
222222 62
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