ACIS

 

Modifies an entity, or list of entities, by bending it about a specified axis. 

Role: The neutral root, bending axis, and bending direction together define the neutral plane for the bending operation. [A neutral plane is the location along which material is neither stretched nor compressed during bending - material above the neutral plane (along the bending direction) is compressed, while material below the neutral plane is stretched. The location of a neutral plane varies with the type of material to be bent.] 

The argument neutral_root is an SPAposition that lies on the neutral plane. 

The argument bend_axis is an SPAunit_vector that defines the rotational axis of the bend. 

The argument bend_direction is an auxiliary SPAunit_vector that defines the direction of the bend. 

Together with the neutral root, the bending axis (ba) and bending direction (bd) define a bending plane whose normal is the vector ba X bd. (The bending axis and bending direction should be perpendicular to one another.) This cross product additionally defines the "positive" and "negative" sides of the entity to be bent. (As remarked below, the positive side is that which is bent during fixed-end bending.) 

The argument bend_radius is a real number that specifies the radius of the bend, as measured from the center of the bend to the neutral plane. 

The argument bend_angle is the angle, in radians, indicating the extent of the bend. 

The argument bend_width is the width of bend region, as measured on the neutral plane. The values of bend_radius, bend_angle, and bend_width are used to determine the region to be bent. Because only two of these are independent, being related by bend_width=bend_radius*bend_angle, specifying bend_width can be considered optional. More generally, assigning zero or negative values to any of these three parameters implies that the parameter is to be computed from the other two. (It is therefore always desirable to specify at most two parameters from among these three.) However, if only thebend_radius is given as positive, the entire entity is bent. 

The argument f_center_bend (optional) is a logical type specifying the final orientation of the bend, that is, whether it is to be considered a center bend or a fixed-end bend. If f_center_bend is set toTRUE, material on both sides of the bending plane are equally bent by one-half the bend_angle value. If f_center_bend is not set, or set to FALSE, the negative side of the bend is fixed, and only the positive side is bent by the extent given by bend_angle. (This mode of bending is called fixed-end bending.) 

For cases where localized bending is desired, the (optional) array of positions bend_regions may be used to specify the portions of the entity to bend. (One or more positions can be provided.) These positions must be either within the components to be bent, or on their faces. The given positions are tested to determine if they are within the bending region, and must lie on a face in order to be used. If any of the bend positions is invalid (outside the bending region or outside the entity and its faces), no bending is performed. 

If the width of the specified bend region is small, a bend may fail no matter how small the bend angle. Specifically, when this width is comparable to the tolerances of nearby entities, it becomes impossible even to define such a region. 

Effect: Changes model 

Journal: Available 

Parameters:

in_entity

entity to bend.

neutral_root

location on the neutral plane.

bend_axis

bend axis.

bend_direction

bend direction.

radius

bend radius.

angle

bend angle (in radians) = 0.

width

bend width = 0 (radius*angle).

f_center_bend

bend is symmetric about the bend direction if TRUE.

n_points

number of positions in the bend_regions array.

bend_regions

array of positions on the faces to be bent (for localized bending).

opts

ACIS options.