Nonstructural mass verification

The nonstructural mass contribution is specified in the form of a total mass to be applied over an element set. Several element types are tested in each input file, with two elements in the model for each element type. Each element pair is subjected to equivalent displacements (and rotations in the case of beams and shells) such that their response is dynamic. Tests of membranes and shells are performed with and without the specification of nodal thickness. The reaction forces for the constrained nodes of each pair of elements are output for comparison purposes.

The nonstructural mass contribution is specified in the form of a total mass to be applied over the entire model. Several element types are tested in each input file with two elements (test and reference) in the model for each element type. The material density of a “reference” element is chosen to be eight times that of a “test” element. A total mass equal to a third of all “reference” elements is distributed over the entire model. In the case of a mass proportional distribution of the nonstructural mass, the effective element densities of a “reference” element and a “test” element remain at the 8:1 ratio; with the volume proportional distribution, the ratio changes to 4:1. In either distribution any “test” and “reference” element pair would have different mass; hence, the reaction forces are not expected to match.

In Abaqus/Explicit each element pair is subjected to equivalent displacements (and rotations in the case of beams and shells) such that their response is dynamic. In Abaqus/Standard a single- step static analysis is carried out with gravity loads. Rebar defined using the procedure to specify layers of reinforcement as part of the element section definition are included where applicable. Under mass proportional distribution of a total nonstructural mass, the elements with rebar defined using the procedure to specify layers of reinforcement as part of the element section definition attract a higher nonstructural mass compared to those elements without the rebar. However, the same is not true when the rebar are defined using the element-based rebar procedure. Tests of membranes and shells are performed with and without the specification of nodal thickness. The reaction forces for the constrained nodes of each pair of elements are output. In Abaqus/Explicit the element stable time increment values are also output for comparison. These values for a “reference” element and a “test” element are not expected to be identical but should correspond to the modified spatial distribution of the mass in the model.

The nonstructural mass contribution is specified in the form of a mass per unit volume to be applied over an element set. Several element types are tested in each input file, with two elements in the model for each element type. Each element pair is subjected to equivalent displacements (and rotations in the case of beams and shells) such that their response is dynamic. Tests of membranes and shells are performed with and without the specification of nodal thickness. The reaction forces for the constrained nodes of each pair of elements are output for comparison purposes.

The nonstructural mass contribution is specified in the form of a mass per unit area to be applied over an element set. Several element types are tested in each input file, with two elements in the model for each element type. Each element pair is subjected to equivalent displacements (and rotations in the case of beams and shells) such that their response is dynamic. Tests of membranes and shells are performed with and without the specification of nodal thickness. The reaction forces for the constrained nodes of each pair of elements are output for comparison purposes.

The nonstructural mass contribution is specified in the form of a mass per unit length to be applied over an element set. Several element types are tested in each input file, with two elements in the model for each element type. Each element pair is subjected to equivalent displacements (and rotations in the case of beams and shells) such that their response is dynamic. The reaction forces for the constrained nodes of each pair of elements are output for comparison purposes.