Staircase Design with framat

[HoneyBadger919]

Hi folks,

I'm trying to use the framat code to model a flight of stairs through a doubly clamped 3D beam but I continue to get wrong results. It may be because of the cross-section orientation property which I interpreted the same way it works in Abaqus.
As you can see from the picture I get non-zero results just in the vertical direction along which the distributed line load is applied, and for bending moments around the Y axis of the cross-section

I attach here the code I implemented modifying "example_model2.py".

`from framat import Model

model = Model()

#Units MPa, N, mm

mat = model.add_feature('material', uid='cls')
mat.set('E', 30000)
mat.set('G', 12500)
mat.set('rho', 0.01)

#Rectangular cross-section 690 mm x 125 mm
cs = model.add_feature('cross_section', uid='scala')
cs.set('A', 86250)
cs.set('Iy', 1.12305e8)
cs.set('Iz', 34.2197e8)
cs.set('J', 4.49219e8)

beam = model.add_feature('beam')
beam.add('node', [0.0, 0, 0], uid='a')
beam.add('node', [1010, 0, 714], uid='b')
beam.add('node', [1308, 171, 1129], uid='c')
beam.add('node', [1308, 519, 1988], uid='d')
beam.add('node', [1010, 691, 2403], uid='e')
beam.add('node', [200, 691, 2540], uid='f')

beam.set('nelem', 20)

beam.add('material', {'from': 'a', 'to': 'f', 'uid': 'cls'})
beam.add('cross_section', {'from': 'a', 'to': 'f','uid': 'scala'})
beam.add('orientation', {'from': 'a', 'to': 'b', 'up': [0, 1, 0]})
beam.add('orientation', {'from': 'b', 'to': 'c', 'up': [-0.57464, 1, 0]})
beam.add('orientation', {'from': 'c', 'to': 'd', 'up': [1, 0, 0]})
beam.add('orientation', {'from': 'd', 'to': 'e', 'up': [1, 1.4136, 0]})
beam.add('orientation', {'from': 'e', 'to': 'f', 'up': [0, 1, 0]})

beam.add('distr_load', {'from': 'a', 'to': 'b', 'load': [0, 0, -14.34, 0, 0, 0]})
beam.add('distr_load', {'from': 'b', 'to': 'c', 'load': [0, 0, -14.34, 0, 0, 0]})
beam.add('distr_load', {'from': 'c', 'to': 'd', 'load': [0, 0, -14.34, 0, 0, 0]})
beam.add('distr_load', {'from': 'd', 'to': 'e', 'load': [0, 0, -14.34, 0, 0, 0]})
beam.add('distr_load', {'from': 'e', 'to': 'f', 'load': [0, 0, -14.34, 0, 0, 0]})

bc = model.set_feature('bc')
bc.add('fix', {'node': 'a', 'fix': ['all']})
bc.add('fix', {'node': 'f', 'fix': ['all']})

pp = model.set_feature('post_proc')
pp.set('plot_settings', {'show': True})
pp.add('plot', ['undeformed', 'deformed', 'node_uids', 'nodes', 'forces'])

results = model.run()

load_vector = results.get('tensors').get('comp:F')
print(load_vector)`

Let me know if you can help me clarify this
Thanks!

[HoneyBadger919]

I corrected some coordinates of the problem and I specified for each branch the direction of the z-axis of the cross-section in the orientation properties. The output is still wrong anyhow

`from framat import Model

model = Model()

=== UNIT SYSTEM ===

MPa, N, mm

mat = model.add_feature('material', uid='cls')
mat.set('E', 30000)
mat.set('G', 12500)
mat.set('rho', 0.001)

#Rectangular cross-section 690 mm x 125 mm
cs = model.add_feature('cross_section', uid='scala')
cs.set('A', 86250)
cs.set('Iy', 1.12305e8)
cs.set('Iz', 34.2197e8)
cs.set('J', 4.49219e8)

beam = model.add_feature('beam')
beam.add('node', [0.0, 0, 0], uid='a')
beam.add('node', [1010, 0, 714], uid='b')
beam.add('node', [1308, 171, 1094], uid='c')
beam.add('node', [1308, 519, 1663], uid='d')
beam.add('node', [1010, 691, 2043], uid='e')
beam.add('node', [200, 691, 2540], uid='f')

beam.set('nelem', 20)

beam.add('material', {'from': 'a', 'to': 'f', 'uid': 'cls'})
beam.add('cross_section', {'from': 'a', 'to': 'f','uid': 'scala'})
beam.add('orientation', {'from': 'a', 'to': 'b', 'up': [-0.70674, 0, 1]})
beam.add('orientation', {'from': 'b', 'to': 'c', 'up': [-0.74153, -0.426121, 0.773804]})
beam.add('orientation', {'from': 'c', 'to': 'd', 'up': [0, -1.63705, 1]})
beam.add('orientation', {'from': 'd', 'to': 'e', 'up': [1.28376, -0.74114, 1.34274]})
beam.add('orientation', {'from': 'e', 'to': 'f', 'up': [1, 0, 1.63075]})

beam.add('distr_load', {'from': 'a', 'to': 'b', 'load': [0, 0, -14.34, 0, 0, 0]})
beam.add('distr_load', {'from': 'b', 'to': 'c', 'load': [0, 0, -14.34, 0, 0, 0]})
beam.add('distr_load', {'from': 'c', 'to': 'd', 'load': [0, 0, -14.34, 0, 0, 0]})
beam.add('distr_load', {'from': 'd', 'to': 'e', 'load': [0, 0, -14.34, 0, 0, 0]})
beam.add('distr_load', {'from': 'e', 'to': 'f', 'load': [0, 0, -14.34, 0, 0, 0]})

===== BOUNDARY CONDITIONS =====

bc = model.set_feature('bc')
bc.add('fix', {'node': 'a', 'fix': ['all']})
bc.add('fix', {'node': 'f', 'fix': ['all']})

pp = model.set_feature('post_proc')
pp.set('plot_settings', {'show': True})
pp.add('plot', ['undeformed', 'deformed', 'node_uids', 'nodes', 'forces', 'global_axes','beam_index','bc'])

results = model.run()

load_vector = results.get('tensors').get('comp:F')
print(load_vector)`