MSC Adams FE part 柔性体 多体动力学仿真

Interacting with Adams Modeling Elements
The FE Part interacts with the rest of the Adams model similar to other body types in Adams.
• Markers - Markers on FE Parts must be associated with a single node. The marker need not
Welcome to the FE Part 3
Building FE Parts
Building FE Parts
The FE_Part is composed of small pieces, known as finite elements. The behavior of each element is well known under all possible support and load scenarios. The elements share common points called nodes, section properties are assigned on each node. The basic building blocks to create FE_Part are described below:
Welcome to the FE Part 1
Welcome to the FE Part
2 FE Part
Introduction
Introduction
The FE Part is a wholly Adams-native modeling object with inertia properties and is accurate for very large deformation cases (that is, geometric nonlinearity) of beam-like structures. The FE Part differs from the linear flexible body option within Adams Flex in two significant ways: 1) it has the ability to accurately represent large deformations which the linear modes approach cannot and 2) its modeling does not require an FEA-produced file like the modal neutral file (MNF). The FE Part also differs from the beam force element in that it possesses inertia properties. The inertia properties are specified using symmetric, consistent mass matrix which remains constant. For a more detailed comparison with other methods of modeling geometric nonlinearity within Adams click here. The FE Part has below formulation options:
• Material - Defines Hale Waihona Puke Baidu collection of constants needed to define the stress-strain relationship for a
given physical material. Currently, only elastic behavior is supported. The number of constants varies depending on whether the material is isotropic, orthotropic, or anisotropic.
• Section Properties - Define the cross-sectional property values for each node specifying area
and area moments of inertia (Iyy, Izz and Iyz) of the beam.
• 3D Beam: A three-dimensional fully geometrically nonlinear representation useful for beam-like
structures. Accounts for stretching, shearing, bending, and torsion.
FE_PART contact with hollow sections is not supported.
• There is no problem if the geometry belongs to a any other PART or FLEX_BODY,
only if the geometry belongs to an FE_PART and there is contact on that FE_PART then we do not support it.
• Nodes - Define the neutral axis of the beam, whose axis passes through the origin of each node.
All nodes must be oriented such that the positive x-axis is tangent to the neutral axis of the beam centroid. To this end, we need to specify the location and orientation of the node with respect to the BCS of the element. Also, the number of nodes used, n, determines the number of degrees of freedom (DOF) of the FE Part as such: DOF for 3DBeam : = 3*((4*number_of_nodes)-1), DOF of 2DBeams : = 4*(number_of_nodes). Within Adams View these nodes are objects with names (typical of other Adams View objects) and labels which are single positive integer identifiers passed to Adams Solver. The modeling automation provided by the FE Part create and modify wizard in Adams View will name and label nodes in a consistent fashion, but users may rename FE Nodes.
necessarily be coincident with a node. Adams Solver will compute the initial offset to the node and it will keep the offset in subsequent computations. The marker will move as if it is rigidly attached to its node. Within Adams View an FE Part marker can be defined as either locationbased or node-based. During pre-processing, the location based marker will always remain at the specified location and automatically associate itself with the nearest node even after "remeshing" the FE Part.
• 2D Beam (XY, YZ, or ZX): A two-dimensional geometrically nonlinear representation useful
for beam-like structures whereby the centerline of the beam can be assumed constrained to a plane parallel to the model's global XY, YZ or ZX plane. The 2D Beam can stretch or bend in plane. The 2D Beam will solve faster than the 3D Beam. These formulation options are based on an MSC-authored adaptation of Absolute Nodal Coordinate Formulation (ANCF). The Adams FE Part implementation differs from pure ANCF primarily in that it is more like a hybrid between ANCF and geometrically exact beam theory to overcome the limitations of the conventional ANCF formulation. In this way, the new formulation doesn't suffer from the notorious "shear locking" phenomena. The name "FE Part" is appropriate for this entity since this formulation is rooted in finite element modeling and its implementation within Adams shares the finite element modeling concept of nodes (see below). The FE Part does not support material nonlinearity. Also, currently the FE Part is recommended to be applied only to modeling beam-like structures. Other shapes like plates/shells or solids are not currently directly supported. System linear modes analysis via Adams Linear is not currently supported for models including FE Parts nor are Adams2Nastran exports or analyses using Adams Controls. Note: