pycba.inf_lines.InfluenceLines#

class InfluenceLines(L, EI, R, eletype=None)[source]#

Bases: object

Creates influence lines for an arbitrary beam configuration using CBA

Constructs an influence line object for a beam

Parameters:

  • L (np.ndarray) – A vector of span lengths.

  • EI (Union[float, np.ndarray]) – A vector of member flexural rigidities.

  • R (np.ndarray) – A vector describing the support conditions at each member end.

  • eletype (Optional[np.ndarray]) – A vector of the member types. Defaults to a fixed-fixed element.

Return type:

None.

Methods

create_ils

Creates the influence lines by marching the unit load (load_val) across the defined beam configuration in step distance increments, storing the static analysis results in a vector of pycba.results.BeamResults.

get_il

Returns the influence line at a point of interest for a load effect.

plot_il

Retrieves and plots the IL on either a supplied or new axes.
create_ils(step=None, load_val=1.0)[source]#

Creates the influence lines by marching the unit load (load_val) across the defined beam configuration in step distance increments, storing the static analysis results in a vector of pycba.results.BeamResults.

Parameters:

  • step (Optional[float]) – The distance increment to move the unit load; defaults to beam length / 100.

  • load_val (float, optional) – The nominal value of the “unit load”. The default is 1.0.

Raises:

ValueError – If a static beam analysis does not succeed, usually due to a beam configuration error.

Return type:

None.

get_il(poi, load_effect)[source]#

Returns the influence line at a point of interest for a load effect.

Parameters:

  • poi (float) – The position of interest in global coordinates along the length of the beam.

  • load_effect (str) –

    A single character to identify the load effect of interest, currently one of:

    • V: shear force

    • M: bending moment

    • R: vertical reaction at a fully restrained support

    The vertical reaction nearest the poi is used. For moment reactions use a poi at or just beside the support.

Returns:

(x,eta) – A tuple of the vectors of abcissa and influence ordinates.

Return type:

tuple(np.ndarray,np.ndarray)

plot_il(poi, load_effect, ax=None)[source]#

Retrieves and plots the IL on either a supplied or new axes.

Parameters:

  • poi (float) – The position of interest in global coordinates along the length of the beam.

  • load_effect (str) –

    A single character to identify the load effect of interest, currently one of:

    • V: shear force

    • M: bending moment

    • R: vertical reaction at a fully restrained support

    The vertical reaction nearest the poi is used. For moment reactions use a poi at or just beside the support.

  • ax (Optional[plt.Axes]) – A user-supplied matplotlib Axes object; when None (default), one is created for the plot.