beam Module

defines:

• CBEAM

• BEAMOR

class pyNastran.bdf.cards.elements.beam.BEAMOR(pid, is_g0, g0, x, offt='GGG', comment='')

Bases: pyNastran.bdf.cards.base_card.BaseCard

1	2	3	4	5	6	7	8	9
BEAMOR	PID				G0/X1	X2	X3	OFFT
BEAMOR	39				0.6	2.9	-5.87	GOG

classmethod _init_from_empty()

classmethod add_card(card, comment='')

raw_fields()

type = 'BEAMOR'

write_card(size: int = 8, is_double: bool = False) → str

Writes the card with the specified width and precision

Parameters

sizeint (default=8)

size of the field; {8, 16}

is_doublebool (default=False)

is this card double precision

Returns

msgstr

the string representation of the card

class pyNastran.bdf.cards.elements.beam.CBEAM(eid, pid, nids, x, g0, offt='GGG', bit=None, pa=0, pb=0, wa=None, wb=None, sa=0, sb=0, comment='')

Bases: pyNastran.bdf.cards.elements.bars.LineElement

1	2	3	4	5	6	7	8	9
CBEAM	EID	PID	GA	GB	X1	X2	X3	OFFT/BIT
	PA	PB	W1A	W2A	W3A	W1B	W2B	W3B
	SA	SB

or

1	2	3	4	5	6	7	8	9
CBEAM	EID	PID	GA	GB	G0			OFFT/BIT
	PA	PB	W1A	W2A	W3A	W1B	W2B	W3B
	SA	SB

bit is an MSC specific field NX 2020 added offt

Adds a CBEAM card

Parameters

pidint

property id

midint

material id

nidsList[int, int]

node ids; connected grid points at ends A and B

xList[float, float, float]

Components of orientation vector, from GA, in the displacement coordinate system at GA (default), or in the basic coordinate system

g0int

Alternate method to supply the orientation vector using grid point G0. Direction of is from GA to G0. is then transferred to End A

offtstr; default=’GGG’

Offset vector interpretation flag None : bit is active

bitfloat; default=None

Built-in twist of the cross-sectional axes about the beam axis at end B relative to end A. For beam p-elements ONLY! None : offt is active

pa / pbint; default=0

Pin Flag at End A/B. Releases the specified DOFs

wa / wbList[float, float, float]

Components of offset vectors from the grid points to the end points of the axis of the shear center

sa / sbint; default=0

Scalar or grid point identification numbers for the ends A and B, respectively. The degrees-of-freedom at these points are the warping variables . SA and SB cannot be specified for beam p-elements

commentstr; default=’’

a comment for the card

offt/bit are MSC specific fields

Area()

returns the area of the element face

Centroid()

G0() → int

gets G0

Ga() → int

gets Ga/G1

Gb() → int

gets Gb/G2

Mid()

Nodes()

Nsm()

Placeholder method for the non-structural mass, \(nsm\)

classmethod add_card(card, beamor=None, comment='')

Adds a CBEAM card from BDF.add_card(...)

Parameters

cardBDFCard()

a BDFCard object

beamorBEAMOR() or None

defines the defaults

commentstr; default=’’

a comment for the card

center_of_mass()

the centroid formuala is way more complicated if you consider the nonstructural mass axis

center_of_mass_xform()

A B ———- ^ ^ | wa | wb | | 1———-2

1-2 are the nodes of the bar A-B defines the axis of the shear center

^ z

+–+ | | | | | | 2—> y | +–+ | | +—–+

cross_reference(model: BDF) → None

Cross links the card so referenced cards can be extracted directly

Parameters

modelBDF()

the BDF object

classmethod export_to_hdf5(h5_file, model, eids)

exports the elements in a vectorized way

get_axes(model: BDF) → Tuple[Any, Any, Any, Any, Any]

Gets the axes of a CBAR/CBEAM, while respecting the OFFT flag.

Notes

pyNastran.bdf.cards.elements.bars.rotate_v_wa_wb() for a description of the OFFT flag.

is_passed: bool out: (wa, wb, ihat, jhat, khat)

get_axes_by_nodes(model: BDF, pid_ref, node1, node2, xyz1, xyz2, log)

Gets the axes of a CBAR/CBEAM, while respecting the OFFT flag.

Notes

pyNastran.bdf.cards.elements.bars.rotate_v_wa_wb() for a description of the OFFT flag.

get_edge_ids()

Return the edge IDs

get_offt_bit_defaults()

offt doesn’t exist in NX nastran

get_x_g0_defaults()

X and G0 compete for the same fields, so the method exists to make it easier to write the card

Returns

x_g0varies

g0 : List[int, None, None] x : List[float, float, float]

Notes

Used by CBAR and CBEAM

property is_bit

is the bit flag active?

property is_offt

is the offt flag active?

property node_ids

property nodes

property nodes_ref

raw_fields()

repr_fields()

Gets the fields in their simplified form

Returns

fieldsList[varies]

the fields that define the card

safe_cross_reference(model: BDF, xref_errors)

type = 'CBEAM'

uncross_reference() → None

Removes cross-reference links

validate()

card checking method that should be overwritten

write_card(size: int = 8, is_double: bool = False) → str

Writes the card with the specified width and precision

Parameters

sizeint (default=8)

size of the field; {8, 16}

is_doublebool (default=False)

is this card double precision

Returns

msgstr

the string representation of the card

write_card_16(is_double=False)

pyNastran.bdf.cards.elements.beam._init_offt_bit(card, unused_eid: int, offt_default)

offt doesn’t exist in NX nastran