Plane stress and plane strain piezoelectric elements
Elements tested
CPS3E CPS4E CPS6E CPS8E CPS8RE CPE3E CPE4E CPE6E CPE8E CPE8RE
Problem description
Material:
Linear elastic, Young's modulus = 30 × 106, Poisson's ratio = 0.3, no piezoelectric coupling, isotropic dielectric constant 1.0 × 10−3.
Boundary conditions:
0, 0.
Loading:
Distributed pressure of 1000/length on each edge. Equivalent concentrated shear forces corresponding to distributed shear loading of 1000/length on each edge in the directions shown. Distributed charges of 1000/length on each edge. Concentrated charges at each node to negate the distributed charges, except for the distributed charge of 1000/length on the top surface.
Reference solution
- Stresses
Both plane stress and plane strain elements,
−1000;
and for plane strain elements,
−600.
- Strains
Plane strain elements,
−1.7333 × 10−5, −8.6667 × 10−5.
Plane stress elements,
−2.3333 × 10−5, −8.6667 × 10−5.
- Electrical fluxes
Both plane stress and plane strain elements, 0, −1000.
- Electrical potential gradients
Both plane stress and plane strain elements, 0, −1.0 × 106.
- Displacements
, .
- Potentials
.
Results and discussion
Elements using reduced integration may have additional boundary conditions to those specified above. All elements yield exact solutions. Section output requests to the results (.fil) file and to the data (.dat) file are used in some of the input files to output accumulated quantities on the face in the x–y plane.
Three-dimensional piezoelectric elements
Elements tested
C3D4E C3D6E C3D8E C3D10E C3D15E C3D20E C3D20RE
Problem description
Material:
Linear elastic, Young's modulus 30 × 106, Poisson's ratio 0.3, no piezoelectric coupling, isotropic dielectric constant 1.0 × 10−3.
Boundary conditions:
, , , , .
Loading:
Distributed pressure of 1000/area on each face, and equivalent concentrated forces for shear loading, defined such that all three shear stresses are of magnitude −1000. Distributed charges of 1000/area on each face. Concentrated charges at each node to negate the distributed charges, except for the distributed charge of 1000/area on the top surface.
Reference solution
- Stresses
−1000.
- Strains
−1.3333 × 10−5, −8.6667 × 10−5.
- Electrical fluxes
0, 0, −1000.
- Electrical potential gradients
0, 0, −1.0 × 106.
- Displacements
.
- Potentials
.
Results and discussion
Elements using reduced integration may have additional boundary conditions to those specified above. All elements yield exact solutions. Section output requests to the results (.fil) file and to the data (.dat) file are used in some of the input files to output accumulated quantities on the face in the x–y plane.
Axisymmetric piezoelectric elements
Elements tested
CAX3E CAX4E CAX6E CAX8E CAX8RE
Problem description
Material:
Linear elastic, Young's modulus 30 × 106, Poisson's ratio 0.3, no piezoelectric coupling, isotropic dielectric constant 1.0 × 10−3.
Boundary conditions:
Loading:
Distributed pressure of 1000/area on each face. Distributed charges of 1000/area on each face. Concentrated charges at each node to negate the distributed charges, except for the distributed charge of 1000/area on the top surface.
Reference solution
- Stresses
−1000, 0.
- Strains
−1.3333 × 10−5, 0.
- Electrical fluxes
0, −1000.
- Electrical potential gradients
0, −1.0 × 106.
- Displacements
= −1.33 × 10−2 along 1000, −1.33 × 10−5z.
- Potentials
.
Results and discussion
Elements using reduced integration may have additional boundary conditions to those specified above. All elements yield exact solutions. Section output requests to the results (.fil) file and to the data (.dat) file are used in some of the input files to output accumulated quantities on the face in the x–y plane.
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