ProductsAbaqus/StandardAbaqus/ExplicitAbaqus/CAE Defining the isotropic mass valueYou specify a mass magnitude, which is associated with the three translational degrees of freedom at the node of the element. Specify mass, not weight. You must associate this mass with a region of your model. Input File Usage MASS, ELSET=name mass magnitude where the ELSET parameter refers to a set of MASS elements. Abaqus/CAE Usage Property or Interaction module: Point mass/inertia: select point: Magnitude: Isotropic: mass magnitude: Defining the mass matrix explicitly in Abaqus/StandardYou can define a general mass matrix explicitly in Abaqus/Standard if the introduction of individual terms on and off the diagonal of the mass matrix is desired. See User-defined elements for details. Abaqus/CAE Usage Defining the mass matrix explicitly is not supported in Abaqus/CAE. Defining the anisotropic mass tensorYou can specify the mass as anisotropic by giving the three principal values and the principal directions. When the orientation of the principal directions is not specified, they are assumed to coincide with the global axes. In a large-displacement analysis the local axes of the anisotropic mass rotate with the rotation, if active, of the node to which the anisotropic mass is attached. The rotation degree of freedom is active at a node if that node is connected to a beam, a conventional shell, a rotary inertia element, or a rigid body. You can specify mass proportional loads such as gravitation on an anisotropic mass. Damping and mass scaling can also be used with an anisotropic mass. Specify mass, not weight. You must associate this mass with a region of your model. Input File Usage MASS, ELSET=name, TYPE=ANISOTROPIC, ORIENTATION=orientation_name , , where the ELSET parameter refers to a set of MASS elements. Abaqus/CAE Usage Property or Interaction module: Point mass/inertia: select point: Magnitude: Anisotropic: , , and: Defining damping for MASS elementsIn Abaqus/Standard you can define mass proportional damping for direct-integration dynamic analysis or composite damping for modal dynamic analysis. Although both damping definitions can be specified for a set of MASS elements, only the damping that is relevant to the particular dynamic analysis procedure will be used. In Abaqus/Explicit mass proportional damping can be defined for MASS elements. DynamicsYou can define inertia proportional damping for MASS elements in direct-integration dynamic analysis or explicit dynamic analysis. See Material damping for details. Input File Usage MASS, ALPHA= Abaqus/CAE Usage Property or Interaction module: Point mass/inertia: select point: Damping: Alpha:: Modal dynamicsYou can define the fraction of critical damping to be used with the MASS elements when calculating composite damping factors for the modes when used in modal dynamic analysis. See Material damping for details. Input File Usage MASS, COMPOSITE= Abaqus/CAE Usage Property or Interaction module: Point mass/inertia: select point: Damping: Composite:: |