m_n_kappa.crosssection.CrossSectionBoundaries#

class m_n_kappa.crosssection.CrossSectionBoundaries(sections)#

Bases: Crosssection

Compute the Boundary-Values for the cross_section

New in version 0.1.0.

get_boundaries() gives the curvature boundary values under positive and negative curvature

Parameters:: sections (list[Section]) – sections of the given cross_section

Examples

First the sections for the cross-section are created.

>>> from m_n_kappa import Concrete, Steel, Rectangle
>>> concrete = Concrete(f_cm=35.0)
>>> concrete_geometry_1 = Rectangle(
...     top_edge=0.0, bottom_edge=10.0, width=10.0, left_edge=-10.0)
>>> concrete_section_1 = concrete + concrete_geometry_1
>>> steel = Steel(f_y=355, failure_strain=0.15)
>>> steel_geometry = Rectangle(
...     top_edge=10.0, bottom_edge=20.0, width=10.0)
>>> steel_section = steel + steel_geometry

These sections are passed to CrossSectionBoundaries in form of a list.

>>> from m_n_kappa.crosssection import CrossSectionBoundaries
>>> cross_section_boundaries = CrossSectionBoundaries(sections=[concrete_section_1, steel_section])

get_boundaries gives us then a Boundaries class, where a variety of values are saved regarding the boundaries of our cross-section.

>>> boundaries = cross_section_boundaries.get_boundaries()

The following values are given for positive and negative curvature. In case of values under negative curvature only boundaries.negative plus the desired property is to be called. Hereafter, only examples under positive curvature are given.

The maximum positive curvature is given as follows:

>>> boundaries.positive.maximum_curvature.curvature
0.0076749999999999995

The boundary-condition representing the point of failure is given as follows:

>>> boundaries.positive.maximum_curvature.start
StrainPosition(strain=-0.0035, position=0.0, material='Concrete')

Whereas method compute gives as the maximum curvature assuming another StrainPosition points.

>>> from m_n_kappa import StrainPosition
>>> boundaries.positive.maximum_curvature.compute(StrainPosition(-0.0035, 0, 'Concrete'))
0.0076749999999999995

get_boundaries() implements the above given behaviour and returns the boundary values directly without using CrossSectionBoundaries.

Methods

`add_section`(section)	add a `Section` to this cross-section
`concrete_slab_width`()	full width of the concrete slab
`decisive_maximum_negative_strain_position`()	minimum of all maximum negative strains
`decisive_maximum_positive_strain_position`()	minimum of all maximum positive strains
`get_boundaries`()	curvature boundary values under positive and negative curvature
`get_boundary_conditions`()	curvature boundary values under positive and negative curvature
`get_sub_cross_sections`()	get cross-section split into slab- and girder-sections (the sub-cross-sections)
`left_edge`()	outer left-edge of the concrete-slab
`maximum_negative_strain`()	determine maximum positive strain of all sections associated with this cross-section
`maximum_positive_strain`()	determine maximum positive strain of all sections associated with this cross-section
`right_edge`()	outer right-edge of the concrete-slab
`sections_not_of_type`(section_type)	get a list of sections that are not of the specified typ
`sections_of_type`(section_type)	get a list of sections that are of the specified type associated with this cross-section
`strain_positions`([strain_1, strain_2, ...])	get all `StrainPosition`-values between `strain_1` and `strain_2`

Attributes

`bottom_edge`	overall vertical position of the bottom edge of the cross-section \(z_\mathrm{bottom}\)
`girder_sections`	`Section` belonging to te girder
`half_point`	vertical middle between and bottom
`height`	height of the cross-section
`maximum_negative_curvature`	`EdgeStrains` reaching the maximum possible negative curvature
`maximum_positive_curvature`	`EdgeStrains` reaching the maximum possible positive curvature
`section_type`	section-type this cross-section is associated with, if it is only one
`sections`	all sections associated with this cross-section
`slab_effective_width`	effective widths of the (concrete) slab
`slab_sections`	all slab-sections of this cross-section
`top_edge`	top-edge of the cross-section \(z_\mathrm{top}\)

add_section(section)#

add a Section to this cross-section

Parameters:: section (Section) – section to add to this cross-section
Return type:: None
Raises:: ValueError – if section is not of type Section

concrete_slab_width()#

full width of the concrete slab

Return type:: float

decisive_maximum_negative_strain_position()#

minimum of all maximum negative strains

New in version 0.2.0.

Return type:: StrainPosition

decisive_maximum_positive_strain_position()#

minimum of all maximum positive strains

New in version 0.2.0.

Return type:: StrainPosition

get_boundaries()#

curvature boundary values under positive and negative curvature

New in version 0.2.0: neutral_axes to compute the highest and lowest position of the neutral axis under a given curvature

The boundary values are derived from the stress-strain-curves applied to the sections that are associated with the given cross-section

Returns:: curvature boundary values under positive and negative curvature derived from the given material curves
Return type:: Boundaries

get_boundary_conditions()#

curvature boundary values under positive and negative curvature

Returns:: curvature boundary values under positive and negative curvature
Return type:: Boundaries