Release rotational degrees of freedom

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

B21

B22

B23

B31

B32

B33

Features tested

Various types of hinged connections are tested by releasing one or more rotational degrees of freedom. Equivalent models using multi-point constraints are included for comparison.

Problem description

Two beam elements are aligned with the x-axis, joined at the center, and clamped at nodes 1 and 4. Rotational degrees of freedom are released at the center, node 2. Equivalent MPC definitions are used to connect two separate nodes at the center, nodes 2 and 3.

Loading:

Step 1: The left half of the model is loaded by forces per unit length, PY = −1000 and PZ = 1000.

The right half of the model is loaded by forces per unit length, PY = 1000 and PZ = −1000.

Step 2: The loads that were applied in the first step are applied again, this time using NLGEOM for large-displacement analysis.

Results and discussion

The results are the same for the equivalent multi-point constraint models.

Input files

xreleasepinx2.inp: Static steps, release all the rotational degrees of freedom for a beam in a plane.
xmpcpinx2.inp: Static steps, equivalent MPC type PIN for a beam in a plane.
xreleasepinx3.inp: Static steps, release all the rotational degrees of freedom for a beam in space.
xmpcpinx3.inp: Static steps, equivalent MPC type PIN for a beam in space.
xreleaserevo2.inp: Static steps, release one rotational degree of freedom for a beam in space.
xmpcrevo2.inp: Static steps, equivalent MPC type REVOLUTE plus MPC type PIN for a beam in space.
xreleaseuniv2.inp: Static steps, release two rotational degrees of freedom for a beam in space.
xmpcuniv2.inp: Static steps, equivalent MPC type UNIVERSAL plus MPC type PIN for a beam in space.
xreleaseuniv3.inp: Frequency, steady-state dynamics, modal dynamic, and response spectrum steps; release two rotational degrees of freedom for a beam in space.
xmpcuniv3.inp: Frequency, steady-state dynamics, modal dynamic, and response spectrum steps; equivalent MPC type UNIVERSAL plus MPC type PIN for a beam in space.