Skip to main content
Version: 14

viktor.external.rfem

LoadingType​

class viktor.external.rfem.LoadingType(value, names=None, *values, module=None, qualname=None, type=None, start=1, boundary=None)

Bases: Enum

LOAD_CASE: LoadingType = 1
LOAD_COMBINATION: LoadingType = 2

RFEMAction​

class viktor.external.rfem.RFEMAction(id_)

Bases: ABC

Abstract base class of all RFEM action objects.

EnergyOptimizationAction​

class viktor.external.rfem.EnergyOptimizationAction(load_cases, loading_type=LoadingType.LOAD_CASE, *, goal, accuracy)

Bases: RFEMAction

Performs an iterative analysis (consisting of a series of RFEM analyses) to solve for the magnitude of the

1st nodal load, such that the energy at that node (approximately) equals the ‘goal’. The iteration comes to a finish if the change in displacement at the node is lower than the specified ‘accuracy’. This is done for each of the load cases specified.

Parameters

  • load_cases (List[int]) – a list of load cases/combinations to do a energy optimization calculation for. None for all load cases/combinations (default: None).

  • loading_type (LoadingType) – defines if integers in ‘load_cases’ must be interpreted as load case (LOAD_CASE) or load combination (LOAD_COMBINATION) numbers (default: LOAD_CASE)

  • goal (float) – energy level [Nm] for which the calculation tries to solve the 1st nodal load. Same goal is used for all load cases/combinations.

  • accuracy (float) – change in displacement [m] of the node corresponding to the 1st nodal load at which the iteration will successfully return. A lower accuracy in general means more iterations. Same accuracy is used for all load cases/combinations.

CopyNodalLoadAction​

class viktor.external.rfem.CopyNodalLoadAction(copy_from_to, loading_type=LoadingType.LOAD_CASE, *, factor=1.0)

Bases: RFEMAction

Copy the nodal load from one load case to the other, applying a factor on the magnitude.

Note: only the 1st nodal load is copied from and to each load case/combination, other loads are ignored. Make

sure that at least 1 such nodal load exists in both the copy-from and copy-to load cases/combinations.

Parameters

  • copy_from_to (List[Tuple[int, int]]) – a list of load case/combination numbers to copy (from, to)

  • loading_type (LoadingType) – defines if integers in ‘copy_from_to’ must be interpreted as load case (LOAD_CASE) or load combination (LOAD_COMBINATION) numbers (default: LOAD_CASE)

  • factor (float) – factor to be applied on the nodal load magnitude (default: 1.0)

WriteResultsAction​

class viktor.external.rfem.WriteResultsAction(load_cases=None, loading_type=LoadingType.LOAD_CASE)

Bases: RFEMAction

Write all nodal deformations (X, Y, Z) and member internal forces (Location, My, Mz, Fy, Fz) for the model in current state, for each of the load cases/combinations requested, so that it is available in get_result().

Parameters

  • load_cases (List[int]) – a list of load cases/combinations to write the results for. None for all load cases/combinations (default: None).

  • loading_type (LoadingType) – defines if integers in ‘load_cases’ must be interpreted as load case (LOAD_CASE) or load combination (LOAD_COMBINATION) numbers (default: LOAD_CASE)

RFEMAnalysis​

class viktor.external.rfem.RFEMAnalysis(rfx_file, actions)

Bases: ExternalProgram

RFEMAnalysis can be used to perform an analysis with RFEM on third-party infrastructure. To start an analysis call the method execute(), with an appropriate timeout (in seconds). To retrieve the model call get_model() and for results call get_result() for the desired load combination (only after execute()).

Exceptions which can be raised during calculation:

Example usage:

# SLS
sls_cases = [1, 2, 3]
sls_optimization = EnergyOptimizationAction(sls_cases, goal=10000, accuracy=0.1)  # goal = 10 kNm, accuracy = 10 cm

# ALS
als_cases = [4, 5, 6]
als_optimization = EnergyOptimizationAction(als_cases, goal=15000, accuracy=0.1)  # goal = 15 kNm, accuracy = 10 cm

# ULS
uls_cases = [7, 8, 9]
uls_creation = CopyNodalLoadAction(list(zip(sls_cases, uls_cases)), factor=1.5)  # ULS = SLS x 1.5

# Write action
write_result_action = WriteResultsAction(sls_cases + als_cases + uls_cases)  # or can be left empty = all cases

actions = [sls_optimization, als_optimization, uls_creation, write_result_action]
rfem_analysis = RFEMAnalysis(rfx_file=my_rfx_file, actions=actions)  # my_rfx_file contains the desired load cases and nodal loads
rfem_analysis.execute(timeout=300)
model = rfem_analysis.get_model()
result_lc1 = rfem_analysis.get_result(1)
result_lc2 = rfem_analysis.get_result(2)
Parameters
get_model(*, as_file=False)

Get the model that is returned after the RFEM analysis.

Parameters

as_file (bool) – Return as BytesIO (default) or File

New in v13.5.0

Return type

Union[BytesIO, File]

get_result(load_case, *, as_file=False)

Get the nodal deformations (X, Y, Z) [m] and member internal forces (Location [m], My and Mz [Nm], Fy and Fz [N]) for a certain load case/combination number.

Parameters

  • load_case (int) – number of the load case/combination to get the result for. A ‘WriteResultsAction’ must have been performed on the corresponding load case/combination to be available.

  • as_file (bool) – Return as BytesIO (default) or File

    New in v13.5.0

Return type

Union[BytesIO, File]