structure pile create command

Syntax

structure pile create keyword

Primary keywords:

by-line    by-nodeids    by-ray

Create a pile represented by one or more elements.

The three main keywords articulate three different techniques of creation: by creating a collection of elements that lie between a beginning and an endpoint (by-line); by specifying an element to be created from an existing pair of nodes (by-nodeids); or by specifying an initial point and a direction to follow (by-ray).

Note that the elements of the pile will be assigned the group name Pile N where N is the ID number of the pile. And the beginning and ending nodes will be assigned the group name Pile Begin and Pile End. See the group, grop-begin, and group-end keywords to customize these assignments.

by-line v1 v2 [pilecreateblock]

Create one element that lies along a straight line between the locations v1 and v2. New nodes associated with the element will also be created (see the id keyword). The nodal connectivity of each new element will be ordered such that the direction from v1 to v2 corresponds with the direction from the begin point to the end point. If there are zones in these locations, the element will be attached to the zones at its nodes such that the translational degrees-of-freedom are rigidly connected to the zones and the rotational degrees-of-freedom are free. If no attachment to zones is desired, then the links may be deleted with the command structure link delete after creating and positioning the element.

by-nodeids i1 i2 [pilecreateblock]

Specify the ID numbers (i1, i2) of two nodes that will define the element. These nodes must already exist—nodes can be created with the structure node create command. Ordering of the nodes defines the pile element coordinate system as follows. The positive \(x\)-direction lies along the line from i1 to i2, and the \(y\)-direction is found by projecting the global \(y\)- or \(x\)-directions onto the element cross-section. The \(y\)-direction can also be modified with the property direction-y.

The new element will not be attached to the grid; if you wish to attach it to the grid, then after creating it, position its nodes with the structure node initialize position command (which will create links and set appropriate attachment conditions for all nodes that are moved into a zone).

by-ray v1 v2 f [pilecreateblock]

Create one element that lies along a straight line starting at v1, proceeding in the direction specified by v2 for a distance given by f. New nodes associated with the element will also be created (see the id keyword). The nodal connectivity of each new element will be ordered such that the direction from v1 corresponds with the direction from the begin point to the end point. If there are zones in these locations, the element will be attached to the zones at its nodes such that the translational degrees-of-freedom are rigidly connected to the zones and the rotational degrees-of-freedom are free. If no attachment to zones is desired, then the links may be deleted with the command structure link delete after creating and positioning the element.

structure pile create Keyword Block

The following keywords may be optionally provided on element creation, using any of the major keywords: by-line, by-nodeids and by-ray.

distinct

Eliminate sharing of nodes among created elements. Every element will create a new set of nodes, even if they are at the same location in space and elements share the same ID number. This option is most commonly used with a later structure node join command to create links connecting nodes at the same location in order to apply custom inter-element behavior.

group s <slot s >

Assign all newly created elements to the group s. The optional keyword slot can be used to specify the group slot; if not specified, the group is assigned to the slot Default. Use of the group logic is described in Groups. If not specified, the default group name assigned will be Pile N where N is the ID number assinged to the pile.

group-begin s <slot s >

A group name that will be assigned to the first node of the elements created along a line. The default name assigned will be Pile Begin.

group-end str:`s` <slot s >

A group name that will be assigned to the first node of the elements created along a line. The default name assigned will be Pile End.

id i

Specify the ID that will be assigned to all new elements created by this command. If this value is not given, then the next available ID will be used. The ID controls potential joining of the two element end-nodes to an existing element as follows. At each end-node location, a new node is created unless all of the following conditions are fulfilled: 1) the ID is given; 2) an existing node is found near the potential new node location; and 3) the found node is part of a pile with ID equal to i.

maximum-length f

Break the element into segments no greater than length f. The segments setting, if provided, is overridden as needed by this setting.

segments i

Break the element into i equal segments, creating new nodes as needed. The default value is 1, indicating that only one element will be created.

snap <b >

Indicate that the first and last positions of the element(s) created will attempt to “snap” to the location of the nearest structural node (attached to any element type) within a radius of 1/2 the element length. If only one end is snapped in this manner, then the entire line created will be offset by the difference between the original and the snapped position.