Materials and sections¶

A material is not a section. A section is a material plus a cross-section (b x h, or a profile); bars use sections. There is no set_section() call: create the new section first, then point the element at it. Pointing a bar at a section name that was never created leaves it without a section.

Materials¶

Material: add¶

To create only a material (for example "create the steel material S355"):

model.create_steel_material('S355')     # steel grade
model.create_rc_material('C25/30')      # concrete class
model.create_timber_material('C24')     # timber class

Each returns the material and is shared if it already exists. A material alone changes nothing in the model until a section uses it. Do not make up a section (or give a section the name of a grade) when the request is for a material.

Material: edit (change the material)¶

Make a material, then change what the section points to; every bar using that section follows:

mat = model.create_rc_material('C25/30')        # concrete class, shared
model.sections['S1'].material_name = mat.name

For steel or timber use create_steel_material('S355') or create_timber_material('C24'). To change only the name: model.rename_material('C25/30', 'Concrete').

Material: remove¶

Delete a material:

model.remove_material('C25/30')

It is refused while a section still uses the material.

Sections of bars¶

Section: add¶

The section makes its material too:

model.create_rc_section('S1', b=0.3, h=0.5, concrete='C30/37')    # b x h in metres
model.create_steel_section('S2', 'IPE300', grade='S355')          # a profile
model.create_timber_bar_section('S3', 0.1, 0.2, timber='C24')

Materials are shared: asking for the same concrete class twice does not duplicate it. The section must exist before the bar that uses it.

Section: edit (change the section)¶

Change the section of an existing bar (give it another section): create the new one, then point the bar at it.

# 1. create the new section (it makes its material too)
model.create_rc_section('S2', b=0.3, h=0.6, concrete='C25/30')

# 2. point the existing bar at it
model.bar_elements_by_id['B1'].section_name = 'S2'

Several bars:

model.create_rc_section('S2', b=0.3, h=0.6, concrete='C25/30')
for bar_id in ('B1', 'B2', 'B3'):
    model.bar_elements_by_id[bar_id].section_name = 'S2'

A steel profile instead:

model.create_steel_section('S3', 'IPE300', grade='S355')
model.bar_elements_by_id['B1'].section_name = 'S3'

To rename a section (the bars that use it follow): model.rename_section('S1', 'Beam').

Section: remove¶

Delete a section:

model.remove_section('S1')

It is refused while a bar still uses the section.

Sections of areas¶

Area section: add and edit¶

An area section is created with its material, then the elements are pointed at it.

model.create_area_section('A2', 'C25/30', thickness=0.25)
model.tri_elements_by_id['T1'].section_name = 'A2'
model.quad_elements_by_id['Q1'].section_name = 'A2'

To change only the material of an area section, as for bars: model.tri_sections['A1'].material_name = mat.name (and quad_sections).

The section of a slab or a wall made with create_polygon comes with the region: see Slabs and walls.

Ids¶

Ids are text ('B1', 'T1', 'Q1'). Read them with the geometry tool before changing anything; do not invent them.