m_n_kappa.crosssection.ComputationCrosssectionCurvature#

class m_n_kappa.crosssection.ComputationCrosssectionCurvature(cross_section, curvature, neutral_axis_value, slab_effective_width=None)#

Bases: ComputationCrosssection

computes a cross-section given a curvature and a neutral axis

New in version 0.1.0.

Parameters:

cross_section (Crosssection | list[Section]) – the cross-section
curvature (float) – curvature to compute values
neutral_axis_value (float) – position_value where strain_value is zero
slab_effective_width (EffectiveWidths) – effective widths’ for the slab (concrete and reinforcement)

See also

ComputationCrosssectionStrain: computes a cross-section under a constant strain_value

Examples

For example a HEB 200 steel girder is computed. First it is created as follows.

>>> from m_n_kappa import IProfile, Steel
>>> steel = Steel(f_y=355, failure_strain=0.15)
>>> i_profile = IProfile(
...     top_edge=0.0, t_w=9.5, h_w=200-2*15, b_fo=200.0, t_fo=15.0)
>>> steel_cross_section = i_profile + steel

To compute the girder a curvature-value as well as a neutral_axis_value needs to be passed to ComputationCrosssectionCurvature.

>>> from m_n_kappa.crosssection import ComputationCrosssectionCurvature
>>> computed_cross_section = ComputationCrosssectionCurvature(
...     cross_section=steel_cross_section, curvature=0.0001, neutral_axis_value=100.0)

As the neutral_axis_value is chosen to be in the mid-height of the cross-section, (almost) zero axial-forces are computed.

>>> round(computed_cross_section.total_axial_force(), 7)
0.0

The moment on the other hand is much higher and assuming Newton and Millimeter as input is here computed to Kilo-Newton-Meter.

>>> computed_cross_section.total_moment() * 0.001 * 0.001
221.07004924606247

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_boundary_conditions`()	curvature boundary values under positive and negative curvature
`get_material_points_inside_curvature`()	gives the points included between the curvature and zero strain_value
`get_sub_cross_sections`()	get cross-section split into slab- and girder-sections (the sub-cross-sections)
`girder_sections_axial_force`()	summarized axial force of the girder sections
`girder_sections_moment`()	summarized moment of the girder 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
`slab_sections_axial_force`()	summarized axial forces of the slab sections
`slab_sections_moment`()	summarized moments of the slab sections
`strain_positions`([strain_1, strain_2, ...])	get all `StrainPosition`-values between `strain_1` and `strain_2`
`total_axial_force`()	summarized axial forces of the cross_section
`total_moment`()	summarized moments of the cross_section

Attributes

`bottom_edge`	overall vertical position of the bottom edge of the cross-section \(z_\mathrm{bottom}\)
`compute_sections`	`Section` in `sections` transformed into `ComputationSection`
`compute_split_sections`	sections split at material points
`computed_girder_sections`	sections of the girder (computed)
`computed_slab_sections`	sections of the slab (computed)
`curvature`	applied curvature to the cross_section
`girder_sections`	`Section` belonging to te girder
`half_point`	vertical middle between and bottom
`height`	height of the cross-section
`neutral_axis`	position_value where strain_value is zero
`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_boundary_conditions()#

curvature boundary values under positive and negative curvature

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