bush Module

Inheritance diagram of pyNastran.bdf.cards.properties.bush

All bush properties are defined in this file. This includes:

  • PBUSH

  • PBUSH1D

  • PBUSH2D (not implemented)

  • PBUSHT

All bush properties are BushingProperty and Property objects.

class pyNastran.bdf.cards.properties.bush.BushingProperty[source]

Bases: pyNastran.bdf.cards.base_card.Property

dummy init

cross_reference(model: BDF) → None[source]
type = 'BushingProperty'
uncross_reference() → None[source]

Removes cross-reference links

class pyNastran.bdf.cards.properties.bush.PBUSH(pid, k, b, ge, rcv=None, mass=None, t=None, comment='')[source]

Bases: pyNastran.bdf.cards.properties.bush.BushingProperty

Generalized Spring-and-Damper Property Defines the nominal property values for a generalized spring-and-damper structural element.

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PBUSH

PID

K

K1

K2

K3

K4

K5

K6

B

B1

B2

B3

B4

B5

B6

GE

GE1

GE2

GE3

GE4

GE5

GE6

RCV

SA

ST

EA

ET

M

MASS

T

ALPHA

TREF

COINL

RCV was added <= MSC 2016 MASS was added <= MSC 2016 T/ALPHA/TREF/COINL was added in MSC 2021

Creates a PBUSH card, which defines a property for a CBUSH

Parameters
pidint

property id

kList[float]

Nominal stiffness values in directions 1 through 6. len(k) = 6

bList[float]

Nominal damping coefficients in direction 1 through 6 in units of force per unit velocity len(b) = 6

geList[float]

Nominal structural damping constant in directions 1 through 6. len(ge) = 6

rcvList[float]; default=None -> (None, None, None, None)

[sa, st, ea, et] = rcv_fields length(rcv_fields) = 4

massfloat; default=None

lumped mass of the CBUSH This is an MSC only parameter.

tList[float]; default=None -> (None, None, None)

[alpha, tref, coinl] = t_fields length(t_fields) = 3 alpha: thermal expansion coefficient; default=0.0 tref: reference temperature; default=0.0 coincident_length: length of CBUSH with coincident grids; default=0.0

commentstr; default=’’

a comment for the card

classmethod _init_from_empty()[source]
classmethod _read_rcv(card, istart)[source]
classmethod _read_var(card, var_prefix, istart, iend)[source]
classmethod add_card(card, comment='')[source]

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

Parameters
cardBDFCard()

a BDFCard object

commentstr; default=’’

a comment for the card

pid = None

Property ID

pname_map = {-23: 'ET', -22: 'EA', -21: 'ST', -20: 'SA', -19: 'GE6', -18: 'GE5', -17: 'GE4', -16: 'GE3', -15: 'GE2', -14: 'GE1', -13: 'B6', -12: 'B5', -11: 'B4', -10: 'B3', -9: 'B2', -8: 'B1', -7: 'K6', -6: 'K5', -5: 'K4', -4: 'K3', -3: 'K2', -2: 'K1'}
raw_fields()[source]
repr_fields()[source]

Gets the fields in their simplified form

Returns
fieldsList[varies]

the fields that define the card

type = 'PBUSH'
update_by_pname_fid(name, value)[source]
validate()[source]

card checking method that should be overwritten

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

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.properties.bush.PBUSH1D(pid: int, k: float = 0.0, c: float = 0.0, m: float = 0.0, sa: float = 0.0, se: float = 0.0, optional_vars=None, comment: str = '')[source]

Bases: pyNastran.bdf.cards.properties.bush.BushingProperty

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PBUSH1D

PID

K

C

M

SA

SE

SHOCKA

TYPE

CVT

CVC

EXPVT

EXPVC

IDTS

IDETS

IDECS

IDETSD

IDECSD

SPRING

TYPE

IDT

IDC

IDTDU

IDCDU

DAMPER

TYPE

IDT

IDC

IDTDV

IDCDV

GENER

IDT

IDC

IDTDU

IDCDU

IDTDV

IDCDV

Creates a PBUSH1D card

Parameters
pidint

property id

kfloat

stiffness

cfloat

Viscous damping

mfloat

mass

safloat

Stress recovery coefficient [1/area].

sefloat

Strain recovery coefficient [1/length].

optional_varsdict[name]
namestr

SHOCKA, SPRING, DAMPER, GENER

valuesList[varies]

the values

SHOCKA:

Coefficients of the following force versus velocity/displacement relationship F(u, v) = Cv * S(u) * sign(v) * |v|^EXPV TYPE CVT CVC EXPVT EXPVC IDTS IDETS IDECS IDETSD IDECSD CVT/CVC : int

Viscous damping coefficient CV for tension v > 0, force per unit velocity.

EXPVT/EXPVCint

Exponent of velocity EXPV for tension v > 0 (or compression v < 0).

IDTSint

Identification number of a TABLEDi entry for tension and compression if TYPE=TABLE. The TABLEDi entry defines the scale factor S, versus displacement u.

IDETS/IDECSint

Identification number of a DEQATN entry for tension if TYPE=EQUAT. The DEQATN entry defines the scale factor S, versus displacement u, for tension u > 0 (or compression v < 0).

IDETSD/IDECSDint

Identification number of a DEQATN entry for tension if TYPE=EQUAT. The DEQATN entry defines the defines the scale factor S, versus displacement u, for tension u > 0 (or compression v < 0).

SPRING:

Nonlinear elastic spring element in terms of a force versus displacement relationship TYPE IDT IDC IDTDU IDCDU

DAMPER:

Nonlinear viscous element in terms of a force versus velocity relationship. TYPE IDT IDC IDTDV IDCDV

GENER:

General nonlinear elastic spring and viscous damper element in terms of a force versus displacement and velocity relationship. For this element, the relationship can only be defined with TYPE=EQUAT (and it’s implicit). IDT IDC IDTDU IDCDU IDTDV IDCDV

TYPEint

the type of the result; {TABLE, EQUAT}

IDT/IDCint

tension/compression table/equation

IDTDU/IDCDUint

du/dt tension/compression table/eq

IDTDV/IDCDVint

dv/dt tension/compression table/eq

_damper_fields()[source]
_gener_fields()[source]
classmethod _init_from_empty()[source]
_properties = ['pname_fid_map']
static _read_damper(v) = Ft(u)[source]
static _read_gener(u, v) = Ft(u, v)[source]
static _read_shock(card, istart)[source]

F(u, v) = Cv * S(u) * sign(v) * |v|^ev

static _read_spring(u) = Ft(u)[source]
_shock_fields()[source]
_spring_fields()[source]
classmethod add_card(card, comment='')[source]

Adds a PBUSH1D card from BDF.add_card(...)

Parameters
cardBDFCard()

a BDFCard object

commentstr; default=’’

a comment for the card

pid = None

Property ID

pname_fid_map = {'C': 'c', 'K': 'k', 'M': 'm'}
raw_fields()[source]
repr_fields()[source]

Gets the fields in their simplified form

Returns
fieldsList[varies]

the fields that define the card

type = 'PBUSH1D'
write_card(size: int = 8, is_double: bool = False) → str[source]

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.properties.bush.PBUSH2D(card=None, comment='')[source]

Bases: pyNastran.bdf.cards.properties.bush.BushingProperty

dummy init

type = 'PBUSH2D'
write_card(size: int = 8, is_double: bool = False) → str[source]

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.properties.bush.PBUSHT(pid, k_tables, b_tables, ge_tables, kn_tables, comment='')[source]

Bases: pyNastran.bdf.cards.properties.bush.BushingProperty

dummy init

classmethod _init_from_empty()[source]
classmethod add_card(card, comment='')[source]

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

Parameters
cardBDFCard()

a BDFCard object

commentstr; default=’’

a comment for the card

raw_fields()[source]
type = 'PBUSHT'
update_by_pname_fid(name, value)[source]
write_card(size: int = 8, is_double: bool = False) → str[source]

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.properties.bush.PBUSH_OPTISTRUCT(pid, k, b, ge, mass, comment='')[source]

Bases: pyNastran.bdf.cards.properties.bush.BushingProperty

Generalized Spring-and-Damper Property Defines the nominal property values for a generalized spring-and-damper structural element.

1

2

3

4

5

6

7

8

9

PBUSH

PID

K

K1

K2

K3

K4

K5

K6

B

B1

B2

B3

B4

B5

B6

GE

GE1

GE2

GE3

GE4

GE5

GE6

M

M1

M2

M3

M4

M5

M6

Creates a PBUSH card, which defines a property for a CBUSH

Parameters
pidint

property id

kList[float]

Nominal stiffness values in directions 1 through 6. len(k) = 6

bList[float]

Nominal damping coefficients in direction 1 through 6 in units of force per unit velocity len(b) = 6

geList[float]

Nominal structural damping constant in directions 1 through 6. len(ge) = 6

massList[float]

Nominal mass in directions 1 through 6.

commentstr; default=’’

a comment for the card

classmethod _init_from_empty()[source]
classmethod _read_var(card, var_prefix, istart, iend)[source]
classmethod add_card(card, comment='')[source]

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

Parameters
cardBDFCard()

a BDFCard object

commentstr; default=’’

a comment for the card

pid = None

Property ID

pname_map = {-23: 'ET', -22: 'EA', -21: 'ST', -20: 'SA', -19: 'GE6', -18: 'GE5', -17: 'GE4', -16: 'GE3', -15: 'GE2', -14: 'GE1', -13: 'B6', -12: 'B5', -11: 'B4', -10: 'B3', -9: 'B2', -8: 'B1', -7: 'K6', -6: 'K5', -5: 'K4', -4: 'K3', -3: 'K2', -2: 'K1'}
raw_fields()[source]
repr_fields()[source]

Gets the fields in their simplified form

Returns
fieldsList[varies]

the fields that define the card

type = 'PBUSH'
validate()[source]

card checking method that should be overwritten

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

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

pyNastran.bdf.cards.properties.bush._append_nones(list_obj, nrequired)[source]

this function has side effects