Members and sections#

Factory functions#

create_section(**kwargs)

Create a section object defining cross-section geometric properties.

create_member(**kwargs)

Create a grillage member combining a section and a material.

Class reference#

Section#

class Section(op_ele_type='elasticBeamColumn', mass=0, c_mass_flag=False, unit_width=False, op_section_type='Elastic', **kwargs)#

Bases: object

Class for structural sections of grillage model. Stores geometric properties of cross sections. This class also parses section inputs into relevant OpenSeesPy command for creating sections in OpenSees framework.

This class wraps `OpenSeesPy` Section() commands - methods for generating commands are handled by the higher hierarchy:class:~ospgrillage.member.GrillageMember class

The constructor takes in two types of keyword arguments.

  1. General section properties - such as A, I, J for example. These properties are parses into the appropriate OpenSees section arguments.

  2. OpenSeespy section arguments - i.e. specific keyword for a specific ops.section() type.

Section information of OpenSeesPy

Constructor takes following inputs to be parse into arguments for `OpenSeesPy` Sections.

Parameters:

  • op_ele_type (str) – OpenSees element type - default elasticBeamColumn

  • op_section_type (str) – OpenSees section type - default Elastic

  • mass (float) – Mass of member.

  • unit_width (bool) – Flag for if unit width properties are defined.

Constructor also takes the following keyword arguments for a section.

Parameters:

  • A (float, optional) – Cross-sectional area.

  • Iz (float, optional) – Second moment of area about the local z axis.

  • Iy (float, optional) – Second moment of area about the local y axis.

  • J (float, optional) – Torsional inertia about the local x axis.

  • Az (float, optional) – Shear area in the local z direction.

  • Ay (float, optional) – Shear area in the local y direction.

Note

Section properties are defined in local coordinates (x, y, z) and are later transformed according to the orientation of the GrillageMember in the grillage model.

GrillageMember#

class GrillageMember(section, material, member_name='Undefined', quad_ele_flag=False, tri_ele_flag=False)#

Bases: object

Class for grillage model members. E.g., longitudinal beam members.

This class parses material and section properties of grillage members into corresponding OpenSeesPy Element() command.

Refer here for more information about

OpenSeesPy Element types and definition workflow.

For developers wishing to expand the library of elements wrapped by GrillageMember, introduce in this class:

  1. The argument input orders of the new element in get_member_prop_arguments().

  2. If the element requires an OpenSeesPy Section definition, add its input arguments to get_section_arguments() and get_ops_section_command().

Init the GrillageMember. Requires two input objects i.e. A Material, and Section.

Parameters:

  • section (Section) – Section class object

  • material (Material) – Material class object

  • member_name (str) – Name of the grillage member (Optional)