A slender beam is modelled with shell elements comparing the computed stresses using 4node and 9node shell elements. In addition, the use of isotropic material and laminates for the computation of the stresses is tested. This test case is intended for computing stresses of nonlayered and layered elements.
The model is meshed using Q4.S.MITC.E4 or Q9.S.MITC elements and uses either the normal isotropic material model or a laminate with three layers, the outer layers being very thin. The beam is modelled in the direction of the yaxis and the shell elements are placed in the xyplane.
The beam is clamped at y=0 and loaded at y=200. For the inplane bending case (case 1) and the traction case (case 2) the traction load along the edge is 0.2. For the outofplane case (case 3) the traction load along the edge is 0.02.
The tip of the beam is loaded on the corners in the x, y or zdirection, respectively, depending on the load case.
Table 17. Input options
eltype num

Identifier to select the element type: num=1 selects Q4; num=2 selects Q9. 
load num

Select the direction of the load: 1: inplane bending (in xyplane); 2: tension in the length of the beam; 3: outofplane bending. 
matid num

Specifies the material of the elements: 1: isotropic, nonlayered material; 2: same isotropic material as 1, but with 3 layers. 
pcoeff val

The value for the Poisson coefficient. Results calculated for p=0.0 and p=0.3. 
Theoretical values (beam theory) for the tip displacement and for the
stresses are readily available (see Python test program
__init__.py
). The figure below shows the deformation
(amplified) in the three loading directions: Outofplane bending (blue),
inplane bending (green) and tension (yellow).