There are two different classes of 2D elements. The basic 2D element is the normal finite elements used for structural applications included in-plane and/or out-of-plane behaviour. The load panel element is a non-structural element used to apply load to beam elements.
All elements that refer to Beam Sections, 2D Properties or 3D Properties require an analysis material. This can either be an explicitly defined material or an implied material from a material grade. The latter are always assume to be elastic isotropic materials.
The block wizard can be activated from the block table view accessed by going to Explorer pane > Data > Blocks. From the table, select the wizard icon to bring up the block wizard dialogue box:
The member wizard can be activated from the Members Table view using the wizard button or from a Graphic view by selecting a member and then Edit member from the right-click menu.
As discussed in the Step-by-Step guide to Environmental Impact, environmental impact parameters for a material type may be specified in the Environmental Impact Wizard. This wizard can be accessed either from the Environmental Impact Specification dialog to specify global parameters, or from the material grades to specify values for a particular user material.
The grid layout definition table and/or dialog is used to define or modify a grid layout, which is a distribution of grid points that can be used to define model geometry using sculpt tools.
A link is unlike other elements in that it does not have stiffness, instead it created a constraint condition between the two ends of the element. The behaviour of a link element is like a rigid constraint with just two nodes. Degrees of freedom that are not linked have no connection at all.
A node with a mass property concentrates mass and inertia at a single point. In a static analysis (linear or nonlinear), the only effect of a mass is to give a loading based on m × g when gravity loads are applied to the structure. In a dynamic analysis both mass and inertia are used in the construction of the mass matrix
In most analysis no material curve needs to be defined, but for LS-DYNA analysis and for nonlinear springs material curves must be defined.
All beam type elements refer to a section defining the geometrical properties (e.g. area, second moment of area) referenced by the element or member through the property number. The set of sections in the model form the Section Library. Individual sections in the section library can have Section Analysis Properties that are modified for analysis, e.g. reducing the J value so that the element doesn't attract torsion. Sections are then grouped in Section Pools.
Springs are a general type of element which can be used to model both simple springs and more sophisticated types of behaviour. For springs connected to ground these are specified directly on a node rather than as an element. The two simplest and most robust types of spring are the axial and rotational springs which have only and axial or rotational stiffness respectively. The more general spring types can violate equilibrium conditions so use be used with care. General non linear springs require material curves to define the load deflection characteristics. A completely general linear spring connected to ground uses a material matrix to define the stiffness, but this matrix must be positive definite. Springs follow the same local axis definition as beam, but the exceptions are zero length springs and nodal springs. For zero length springs the local axis is the constraint axis or the first node and for nodal springs it is the constraint axis of the node.