Hello,
I am modelling a three-point bending test for a 3DCP specimen in Abaqus/Explicit. The supports (S1 and S2) are modelled as discrete rigid shell plates (R3D4). I created a reference point (RP) for each support and applied the boundary conditions at the RPs according to the test rules:
S1: Ux = 0, Uy = 0, Uz = 0; Rx = 0, Ry = free, Rz = 0
S2: Ux = free, Uy = 0, Uz = 0; Rx = 0, Ry = free, Rz = 0
When running Abaqus/Explicit, the job aborts with an error indicating that one or more rigid bodies have zero rotary inertia about an axis while the corresponding rotational DOF is unconstrained. The message suggests defining rotary inertia at the RPs or constraining all rotational DOFs (see attached figure).
Could you please advise on the preferred way to address this while remaining consistent with the test boundary conditions? Specifically, is it acceptable to:
keep the supports as discrete rigid plates and assign a small rotary inertia at the support RPs (so Ry can remain free without solver issues), or
instead model the supports as deformable plates/blocks (with sufficiently high stiffness) and make RPs rigid body constrained to the supports ?
and for each case what is contact option recommended in this test? i use General - contact is this enough and does changing it affect the results a lot ?
