Shell offset

This problem contains basic test cases for one or more Abaqus elements and features.

This page discusses:

Elements tested
Features tested
Problem description
Results and discussion
Input files

ProductsAbaqus/Standard

Elements tested

S4R

S8R

S8RT

Features tested

Shell offset used with a shell cross-section and a shell general section.

Problem description

The model consists of a plate with a length of 10.0, a width of 1.0, and a thickness of 0.2. The end at $x = $ 0 is fixed, and all degrees of freedom except the rotation about the $y$ -axis are constrained at $x = $ 10. A rotation $ϕ_{y} = $ −0.1 is applied at $x = $ 10 for the static analyses. A single shell element with an offset of half the shell's thickness from the midsurface is used to model the plate. Simpson's rule is used for the shell cross-section for all the elements.

Two additional input files (esf4sxsd.inp and esf4sgsb.inp) test the bending of a cantilevered half-cylinder. The model has a radius of 5, a length of 20, and a thickness of 0.2. One end is completely constrained, and a uniform upward pressure is applied to all the elements. A general, nonlinear static procedure is included.

Elastic material properties are used to define a material with $E = $ 3.0 × 10⁶ and $ν = $ 0.25 in all cases.

Results and discussion

The verification of the shell offset results is based on the formulation described in Transverse shear stiffness in composite shells and offsets from the midsurface. The results are verified by comparing them to the results obtained from an equivalent model without offset. This equivalent model is defined using a composite shell section and a general shell section, where an extra layer that has a negligible material modulus is added to the model.

Input files

Composite shell section offset:

esf4sxsc.inp: S4R elements; static steps.
esf4sxsd.inp: S4R elements; static steps using NLGEOM.
es68sxsc.inp: S8R elements; static steps.
es68sxsd.inp: S8R elements; frequency, steady-state dynamics, modal dynamic, and response spectrum steps.
es68sxra.inp: S8R elements; static steps with rebars.
es68sxrb.inp: S8R elements; frequency, steady-state dynamics, modal dynamic, and response spectrum steps with rebars.
es68sxxa.inp: S8R elements; static steps with thermal expansion.
es68sxxb.inp: S8RT elements; coupled temperature-displacement steps with static loading.

General shell section offset:

esf4sgsa.inp: S4R elements; static steps.
esf4sgsb.inp: S4R elements; static steps using NLGEOM.
es68sgsa.inp: S8R elements; static steps.
es68sgsb.inp: S8R elements; frequency, steady-state dynamics, modal dynamic, and response spectrum steps.