24 docs tagged with "properties"

2D element properties are used to describe two different classes of 2D elements:

This defines the type and properties ascribed to each 3D Element Property Number. Properties can be edited using the “3D Property Definition”.

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.

Cable properties are most useful for GsRelax nonlinear analysis, where all the cable elements with the same property form a cable that is allowed to slide. Cable elements can also be used in the Gss solver where they are treated in the same way as ties.

A number of parameters which control the calculation can be adjusted.

Damper elements are only considered in the explicit nonlinear solver. Including damper elements in a modal dynamic analysis gives rise to a completely different problem with complex results. This is not considered in GSA. Dampers follow the same local axis definition as beam, but the exceptions are zero length dampers and nodal dampers. For zero length dampers the local axis is the constraint axis or the first node and for nodal dampers it is the constraint axis of the node

Definition

Definition

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.

A spring matrix allows the user to define the stiffness terms explicitly for a nodal spring. The matrix option cannot be used with internal springs.

In output tables that include an entity number and a case number per line, the default sequence of lines is output in ascending order.

Definition

Form-finding is an analysis which seeks to determine the shape of a lightweight structure under a set of boundary constraints. During a form-finding analysis with the solver will search for form finding properties with the property number assigned to the element. If none are found, the normal beam section or 2D element properties will be used instead.

There are two aspects to the reinforcement - the reinforcement material and the reinforcement layout.

This page summarizes the section definition and allows extra data to be specified.

Normally the section properties are derived from the section geometry, but in some cases it is convenient to modify some of the parameters.

Definition

Definition

This defines the properties of a spacer chain made up of a series of spacer elements. Each individual spacer chain has its own unique spacer property number. The properties determine how the nodes along the spacer chain are controlled during the form-finding process.

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.

Stage properties are used to specify element properties for analysis stages where these are to differ from the whole model element properties. The table maps from the element property number, to a property number to be used inn the analysis stage. Properties not referenced in the analysis stage properties retain the element property reference.

Design codes have one of two methods for introducing a factor of safety: either applying a factor to the material properties or a reduction to the calculated strength