o3seespy.section

class o3seespy.command.section.Aggregator(osi, mats, section=None)[source]

Bases: SectionBase

The Aggregator Section Class

This command is used to construct a SectionAggregator object which aggregates groups previously-defined UniaxialMaterial objects into a single section force-deformation model. Each UniaxialMaterial object represents the section force-deformation response for a particular section degree-of-freedom (dof). There is no interaction between responses in different dof directions. The aggregation can include one previously defined section.

Initial method for Aggregator

Parameters

  • mats (list) – List of mat objs and dofs of previously-defined uniaxialmaterial objects, mats = [[mattag1,dof1],[mattag2,dof2],...] the force-deformation quantity to be modeled by this section object. one of the following section dof may be used: * 'p' axial force-deformation * 'mz' moment-curvature about section local z-axis * 'vy' shear force-deformation along section local y-axis * 'my' moment-curvature about section local y-axis * 'vz' shear force-deformation along section local z-axis * 't' torsion force-deformation

  • section (obj) – Tag of previously-defined section object to which the uniaxialmaterial objects are aggregated as additional force-deformation relationships (optional)

op_type = 'Aggregator'
class o3seespy.command.section.Bidirectional(osi, e_mod, fy, hiso, hkin, code1='Vy', code2='P')[source]

Bases: SectionBase

The Bidirectional Section Class

This command allows the user to construct a Bidirectional section, which is a stress-resultant plasticity model of two coupled forces. The yield surface is circular and there is combined isotropic and kinematic hardening.

Initial method for Bidirectional

Parameters

  • osi (o3seespy.OpenSeesInstance) –

  • e_mod (float) – Elastic modulus

  • fy (float) – Yield force

  • hiso (float) – Isotropic hardening modulus

  • hkin (float) – Kinematic hardening modulus

  • code1 (str, optional) – Section force code for direction 1

  • code2 (str, optional) – Section force code for direction 2 one of the following section code may be used: * 'p' axial force-deformation * 'mz' moment-curvature about section local z-axis * 'vy' shear force-deformation along section local y-axis * 'my' moment-curvature about section local y-axis * 'vz' shear force-deformation along section local z-axis * 't' torsion force-deformation

Examples

>>> import o3seespy as o3
>>> osi = o3.OpenSeesInstance(ndm=2)
>>> o3.section.Bidirectional(osi, e_mod=1.0, fy=1.0, hiso=1.0, hkin=1.0, code1='Vy', code2='P')
op_type = 'Bidirectional'
class o3seespy.command.section.Elastic2D(osi, e_mod, area, iz, g_mod: Optional[float] = None, alpha_y: Optional[float] = None)[source]

Bases: SectionBase

The Elastic2D Section Class

Initial method for Elastic2D

Parameters

  • osi (o3seespy.OpenSeesInstance) –

  • e_mod (float) – Young’s modulus

  • area (float) – Cross-sectional area of section

  • iz (float) – Second moment of area about the local z-axis

  • g_mod (float (default=True), optional) – Shear modulus (optional for 2d analysis, required for 3d analysis)

  • alpha_y (float (default=True), optional) – Shear shape factor along the local y-axis

Examples

>>> import o3seespy as o3
>>> osi = o3.OpenSeesInstance(ndm=2)
>>> o3.section.Elastic2D(osi, e_mod=1.0, area=1.0, iz=1.0, g_mod=0.0, alpha_y=0.0)
op_type = 'Elastic'
set_a(value, ele=None, eles=None)[source]
set_e_mod(value, ele=None, eles=None)[source]
set_i(value, ele=None, eles=None)[source]
class o3seespy.command.section.Elastic3D(osi, e_mod, area, iz, iy, g_mod, jxx, alpha_y: Optional[float] = None, alpha_z: Optional[float] = None)[source]

Bases: SectionBase

The Elastic3D Section Class

This command allows the user to construct an ElasticSection. The inclusion of shear deformations is optional. The dofs for 2D elastic section are [P, Mz],for 3D are [P,Mz,My,T].

Initial method for Elastic3D

Parameters

  • osi (o3seespy.OpenSeesInstance) –

  • e_mod (float) – Young’s modulus

  • area (float) – Cross-sectional area of section

  • iz (float) – Second moment of area about the local z-axis

  • iy (float) – Second moment of area about the local y-axis (required for 3d analysis)

  • g_mod (float) – Shear modulus (optional for 2d analysis, required for 3d analysis)

  • jxx (float) – Torsional moment of inertia of section (required for 3d analysis)

  • alpha_y (float (default=True), optional) – Shear shape factor along the local y-axis

  • alpha_z (float (default=True), optional) – Shear shape factor along the local z-axis

Examples

>>> import o3seespy as o3
>>> osi = o3.OpenSeesInstance(ndm=2)
>>> o3.section.Elastic3D(osi, e_mod=1.0, area=1.0, iz=1.0, iy=1.0, g_mod=1.0, jxx=1.0, alpha_y=0.0, alpha_z=0.0)
op_type = 'Elastic'
set_a(value, ele=None, eles=None)[source]
set_e_mod(value, ele=None, eles=None)[source]
set_i(value, ele=None, eles=None)[source]
class o3seespy.command.section.ElasticMembranePlateSection(osi, e_mod, nu, h, rho)[source]

Bases: SectionBase

The ElasticMembranePlateSection Section Class

This command allows the user to construct an ElasticMembranePlateSection object, which is an isotropic section appropriate for plate and shell analysis.

Initial method for ElasticMembranePlateSection

Parameters

  • osi (o3seespy.OpenSeesInstance) –

  • e_mod (float) – Young’s modulus

  • nu (float) – Poisson’s ratio

  • h (float) – Depth of section

  • rho (float) – Mass density

Examples

>>> import o3seespy as o3
>>> osi = o3.OpenSeesInstance(ndm=2)
>>> o3.section.ElasticMembranePlateSection(osi, e_mod=1.0, nu=1.0, h=1.0, rho=1.0)
op_type = 'ElasticMembranePlateSection'
class o3seespy.command.section.Fiber(osi, gj: Optional[float] = None, torsion_mat=None)[source]

Bases: SectionBase

The Fiber Section Class

This command allows the user to construct a FiberSection object. Each FiberSection object is composed of Fibers, with each fiber containing a UniaxialMaterial, an area and a location (y,z). The dofs for 2D section are [P, Mz],for 3D are [P,Mz,My,T].

Initial method for Fiber

Supports pre-building

Parameters

  • gj (float) – Linear-elastic torsional stiffness assigned to the section

  • torsion_mat (obj) – uniaxial_material object assigned to the section for torsional response (can be nonlinear)

op_type = 'Fiber'
class o3seespy.command.section.FiberThermal(osi, gj=None)[source]

Bases: SectionBase

The FiberThermal Section Class

This command create a FiberSectionThermal object.The dofs for 2D section are [P, Mz],for 3D are [P,Mz,My]… note::#. The commands below should be called after the section command to generate all the fibers in the section.#. The patch and layer commands can be used to generate multiple fibers in a single command.Commands to generate all fibers:#. fiber`#. :doc:`patch`#. :doc:`layer

Initial method for FiberThermal

Parameters

  • osi (o3seespy.OpenSeesInstance) –

  • gj (None, optional) –

Examples

>>> import o3seespy as o3
>>> osi = o3.OpenSeesInstance(ndm=2)
>>> o3.section.FiberThermal(osi, gj=0.0)
op_type = 'FiberThermal'
class o3seespy.command.section.Isolator2spring(osi, tol, k1, fyo, k2o, kvo, hb, pe, po=0.0)[source]

Bases: SectionBase

The Isolator2spring Section Class

This command is used to construct an Isolator2spring section object, which represents the buckling behavior of an elastomeric bearing for two-dimensional analysis in the lateral and vertical plane. An Isolator2spring section represents the resultant force-deformation behavior of the bearing, and should be used with a zeroLengthSection element. The bearing should be constrained against rotation.

Initial method for Isolator2spring

Parameters

  • osi (o3seespy.OpenSeesInstance) –

  • tol (float) – Tolerance for convergence of the element state. suggested value: e-12 to e-10. opensees will warn if convergence is not achieved, however this usually does not prevent global convergence.

  • k1 (float) – Initial stiffness for lateral force-deformation

  • fyo (float) – Nominal yield strength for lateral force-deformation

  • k2o (float) – Nominal postyield stiffness for lateral force-deformation

  • kvo (float) – Nominal stiffness in the vertical direction

  • hb (float) – Total height of elastomeric bearing

  • pe (float) – Euler buckling load for the bearing

  • po (float, optional) – Axial load at which nominal yield strength is achieved

op_type = 'Isolator2spring'
class o3seespy.command.section.LayeredShell(osi, mats)[source]

Bases: SectionBase

The LayeredShell Section Class

This command will create the section of the multi-layer shell element, including the multi-dimensional concrete, reinforcement material and the corresponding thickness.

Initial method for LayeredShell

Parameters

mats (list) – A list of material objs and thickness, [[mat1,thk1], ..., [mat2,thk2]]

op_type = 'LayeredShell'
class o3seespy.command.section.NDFiber(osi)[source]

Bases: SectionBase

The NDFiber Section Class

This commnand allows the user to construct an NDFiberSection object. Each NDFiberSection object is composed of NDFibers, with each fiber containing an NDMaterial, an area and a location (y,z). The NDFiberSection works for 2D and 3D frame elements and it queries the NDMaterial of each fiber for its axial and shear stresses. In 2D, stress components 11 and 12 are obtained from each fiber in order to provide stress resultants for axial force, bending moment, and shear [P, Mz, Vy]. Stress components 11, 12, and 13 lead to all six stress resultants in 3D [P, Mz, Vy, My, Vz, T].The NDFiberSection works with any NDMaterial via wrapper classes that perform static condensation of the stress vector down to the 11, 12, and 13 components, or via concrete NDMaterial subclasses that implement the appropriate fiber stress conditions.

Initial method for NDFiber

Parameters

osi (o3seespy.OpenSeesInstance) –

Examples

>>> import o3seespy as o3
>>> osi = o3.OpenSeesInstance(ndm=2)
>>> o3.section.NDFiber(osi)
op_type = 'NDFiber'
class o3seespy.command.section.Parallel(osi, secs)[source]

Bases: SectionBase

The Parallel Section Class

Connect sections in parallel.

Initial method for Parallel

Parameters

  • osi (o3seespy.OpenSeesInstance) –

  • secs (list) – Objects of of predefined sections.

Examples

>>> import o3seespy as o3
>>> osi = o3.OpenSeesInstance(ndm=2)
>>> secs = [o3.section.Elastic2D(osi, e_mod=1.0, area=1.0, iz=1.0, g_mod=0.0, alpha_y=0.0),
>>>          o3.section.Elastic2D(osi, e_mod=1.0, area=1.0, iz=1.0, g_mod=0.0, alpha_y=0.0)]
>>> o3.section.Parallel(osi, secs)
op_type = 'Parallel'
class o3seespy.command.section.PlateFiber(osi, mat, h)[source]

Bases: SectionBase

The PlateFiber Section Class

This command allows the user to construct a MembranePlateFiberSection object, which is a section that numerically integrates through the plate thickness with “fibers” and is appropriate for plate and shell analysis.

Initial method for PlateFiber

Parameters

  • osi (o3seespy.OpenSeesInstance) –

  • mat (obj) – Ndmaterial object to be assigned to each fiber

  • h (float) – Plate thickness

Examples

>>> import o3seespy as o3
>>> # Example is currently not working
>>> osi = o3.OpenSeesInstance(ndm=2)
>>> mat = o3.uniaxial_material.Elastic(osi, 1.0)
>>> o3.section.PlateFiber(osi, mat=mat, h=1.0)
op_type = 'PlateFiber'
class o3seespy.command.section.RCCircularSection(osi, core_mat, cover_mat, steel_mat, d, cover_depth, a_s, nrings_core, nrings_cover, newedges, nsteel, gj: Optional[float] = None)[source]

Bases: SectionBase

The RCCircularSection Section Class

This command allows the user to construct an RCCircularSection object, which is an encapsulated fiber representation of a circular reinforced concrete section with core and confined regions of concrete.

Initial method for RCCircularSection

Parameters

  • osi (o3seespy.OpenSeesInstance) –

  • core_mat (obj) – Object of uniaxial_material assigned to each fiber in the core region

  • cover_mat (obj) – Object of uniaxial_material assigned to each fiber in the cover region

  • steel_mat (obj) – Object of uniaxial_material assigned to each reinforcing bar

  • d (float) – Section radius

  • cover_depth (float) – Cover depth (assumed uniform around perimeter)

  • a_s (float) – Area of reinforcing bars

  • nrings_core (int) – Number of fibers through the core depth

  • nrings_cover (int) – Number of fibers through the cover depth

  • newedges (int) – Number of fibers through the edges

  • nsteel (int) – Number of fibers through the steels

  • gj (float, optional) – Gj stiffness

Examples

>>> import o3seespy as o3
>>> osi = o3.OpenSeesInstance(ndm=2)
>>> core_mat = o3.uniaxial_material.Concrete01(osi, -6.0, -0.004, -5.0, -0.014)
>>> cover_mat = o3.uniaxial_material.Concrete01(osi, -5.0, -0.002, 0.0, -0.006)
>>> steel_mat = o3.uniaxial_material.Steel01(osi, 60.0, 30000.0, 0.01)
>>> o3.section.RCCircularSection(osi, core_mat=core_mat, cover_mat=cover_mat, steel_mat=steel_mat, d=1.0,
>>>                              cover_depth=0.10, a_s=0.1, nrings_core=2, nrings_cover=2, newedges=2, nsteel=4, gj=0.0)
op_type = 'RCCircularSection'
class o3seespy.command.section.RCSection2D(osi, core_mat, cover_mat, steel_mat, d, b, cover_depth, atop, abot, aside, nfcore, nfcover, nfs)[source]

Bases: SectionBase

The RCSection2D Section Class

This command allows the user to construct an RCSection2d object, which is an encapsulated fiber representation of a rectangular reinforced concrete section with core and confined regions of concrete and single top and bottom layers of reinforcement appropriate for plane frame analysis.

Initial method for RCSection2D

Parameters

  • osi (o3seespy.OpenSeesInstance) –

  • core_mat (obj) – Object of uniaxial_material assigned to each fiber in the core region

  • cover_mat (obj) – Object of uniaxial_material assigned to each fiber in the cover region

  • steel_mat (obj) – Object of uniaxial_material assigned to each reinforcing bar

  • d (float) – Section depth

  • b (float) – Section width

  • cover_depth (float) – Cover depth (assumed uniform around perimeter)

  • atop (float) – Area of reinforcing bars in top layer

  • abot (float) – Area of reinforcing bars in bottom layer

  • aside (float) – Area of reinforcing bars on intermediate layers

  • nfcore (float) – Number of fibers through the core depth

  • nfcover (float) – Number of fibers through the cover depth

  • nfs (float) – Number of bars on the top and bottom rows of reinforcement (nfs-2 bars will be placed on the side rows)

Examples

>>> import o3seespy as o3
>>> osi = o3.OpenSeesInstance(ndm=2)
>>> core_mat = o3.uniaxial_material.Concrete01(osi, -6.0, -0.004, -5.0, -0.014)
>>> cover_mat = o3.uniaxial_material.Concrete01(osi, -5.0, -0.002, 0.0, -0.006)
>>> steel_mat = o3.uniaxial_material.Steel01(osi, 60.0, 30000.0, 0.01)
>>> o3.section.RCSection2D(osi, core_mat=core_mat, cover_mat=cover_mat, steel_mat=steel_mat, d=1.0, b=1.0, cover_depth=1.0, atop=1.0, abot=1.0, aside=1.0, nfcore=1.0, nfcover=1.0, nfs=1.0)
op_type = 'RCSection2d'
class o3seespy.command.section.SectionBase[source]

Bases: OpenSeesObject

op_base_type = 'section'
set_parameter(osi, pstr, value, ele, eles)[source]
class o3seespy.command.section.Uniaxial(osi, mat, quantity)[source]

Bases: SectionBase

The Uniaxial Section Class

This command is used to construct a UniaxialSection object which uses a previously-defined UniaxialMaterial object to represent a single section force-deformation response quantity.

Initial method for Uniaxial

Parameters

  • osi (o3seespy.OpenSeesInstance) –

  • mat (obj) – Object of uniaxial material

  • quantity (str) – The force-deformation quantity to be modeled by this section object. one of the following section dof may be used: * 'p' axial force-deformation * 'mz' moment-curvature about section local z-axis * 'vy' shear force-deformation along section local y-axis * 'my' moment-curvature about section local y-axis * 'vz' shear force-deformation along section local z-axis * 't' torsion force-deformation

Examples

>>> import o3seespy as o3
>>> osi = o3.OpenSeesInstance(ndm=2)
>>> mat = o3.uniaxial_material.Elastic(osi, 1.0)
>>> o3.section.Uniaxial(osi, mat=mat, quantity='P')
op_type = 'Uniaxial'
class o3seespy.command.section.WFSection2D(osi, mat, d, tw, bf, tf, nfw, nff)[source]

Bases: SectionBase

The WFSection2D Section Class

This command allows the user to construct a WFSection2d object, which is an encapsulated fiber representation of a wide flange steel section appropriate for plane frame analysis.

Initial method for WFSection2D

Parameters

  • osi (o3seespy.OpenSeesInstance) –

  • mat (obj) – Object of uniaxial_material assigned to each fiber

  • d (float) – Section depth

  • tw (float) – Web thickness

  • bf (float) – Flange width

  • tf (float) – Flange thickness

  • nfw (float) – Number of fibers in the web

  • nff (float) – Number of fibers in each flange

Examples

>>> import o3seespy as o3
>>> osi = o3.OpenSeesInstance(ndm=2)
>>> mat = o3.uniaxial_material.Elastic(osi, 1.0)
>>> o3.section.WFSection2D(osi, mat=mat, d=1.0, tw=1.0, bf=1.0, tf=1.0, nfw=1.0, nff=1.0)
op_type = 'WFSection2d'
o3seespy.command.section.gen_fibre_section(osi, y_loc, z_loc, area, mat)[source]

This command allows the user to construct a single fiber and add it to the enclosing FiberSection or NDFiberSection.

Parameters

  • osi –

  • y_loc –

  • z_loc –

  • area –

  • mat_tag –