MbdLoads (hwx.inspire.motion)#

class MbdLoads(part, analysis=None)#

Bases: list

Loads (forces, torques, accelerations) from an MbdAnalysis that are applied to a part (parts if in a Rigid Group or ground) at specified time steps.

The forces will sum to 0 at each time step. They are used to create load cases for Inspire FE Optimize & Analyze.

Generate loads for part using the current MbdAnalysis: loads = MbdLoads (part)
Filter loads to contain peak force time steps between 1 and 10 seconds: peaks = loads.timeSlice(1, 10).peaks ()
Add in every 5 time steps: loads = loads[::5] + peaks
Generate load cases, write to csv: loads.createLoadCases () loads.writeCsv (‘test.csv’)

Attribute Table#
Name	Type
`frames`	`property`
`times`	`property`

Method Table#
Name	Description
`analyzePart` (self, sumAtRegion=False, params={}, runOptions={})	Run an OptiStructAnalysis using loads.
`copy` (self, items=None)	Create a copy of self containing the passed items
`countLoadCases` (self, **kwds)	How many load cases will be created
`createLoadCases` (self, deactivateRest=False, **kwds)	Create inspire LoadCases out of the load data.
`evenlySpaced` (self, numSamples, includeBounds=True)	Returns a filtered set of loads.
`filter` (self, filter)	Filter time steps using filter function
`getChannels` (self, load, components)	Get run data for a load at every timeStep
`getObjectLoads` (analysis=None, forDrawing=True)
`optimizePart` (self, sumAtRegion=False, params={}, runOptions={})	Run a TopologyOptimization using loads.
`peaks` (self, peaksPerComp=5, components=’FX FY FZ FM TX TY TZ TM’, forceThreshold=1e-05, torqueThreshold=0.001)	Returns a filtered set of loads. For each joint, ‘peaksPerComp’ peaks
`timeSlice` (self, start=None, end=None)	Get all time steps between a start and end time inclusive
`writeCsv` (self, file, wrtDesignPos=False)	Write loads to csv file

Example

from hwx import inspire
from hwx.inspire import motion
import tempfile

model = inspire.openTutorialFile("Motion/M01_FourBar.stmod")
analysis = motion.MbdAnalysis()
analysis.analyze(end=1, dtout=1/5)

# Generate loads for part using the current MbdAnalysis
# Loads are all the forces/torques on a specific part
part = model.getChild('Link Single Slot')
loads = motion.MbdLoads(part, analysis)

# Filter loads to contain peak force in time steps between 1 and 10 seconds
peaks = loads.timeSlice(1, 10).peaks(peaksPerComp=1, components="FM")
print("Peak Force FM is at time = {}, at frame = {}".format(
   peaks[0].time, peaks[0].frame))
for key, vals in peaks[0].loads.items():
   print("For '{}' -> Loads are: ".format(key))
   print(vals)

# Generate load cases, write to csv
print("There will be generated {} load cases".format(loads.countLoadCases()))

# Create Forces, Torques, Accelerations at each time step
loads.createLoadCases()

# write load cases in a csv
file = tempfile.gettempdir()+'/test.csv'
loads.writeCsv(file)
with open(file) as f:
   print(f.read())

createLoadCases(deactivateRest=False, **kwds)#: Create inspire LoadCases out of the load data.

countLoadCases(**kwds)#: How many load cases will be created so we can warn the user if there are a lot

writeCsv(file, wrtDesignPos=False)#

Write loads to csv file

wrtDesignPos Means force / torque directions will be transformed to the: parts model position.

analyzePart(sumAtRegion=False, params={}, runOptions={})#

Run an OptiStructAnalysis using loads.

Parameters:

sumAtRegion (bool) – use a Summed at Contact Region representation of the contact forces instead of the individual contact forces themselves.
params (dict) – See OptiStructAnalysis.Params.
runOptions (dict) – See OptiStructAnalysis.RunOptions.

Returns:

The synthesis with results.

Return type:

OptiStructAnalysis

optimizePart(sumAtRegion=False, params={}, runOptions={})#

Run a TopologyOptimization using loads.

Parameters:

sumAtRegion (bool) – use a Summed at Contact Region representation of the contact forces instead of the individual contact forces themselves.
params (dict) – See TopologyOptimization.Params.
runOptions (dict) – See TopologyOptimization.RunOptions.

Returns:

The synthesis with results.

Return type:

TopologyOptimization

getChannels(load, components)#: Get run data for a load at every timeStep

filter(filter)#: Filter time steps using filter function

evenlySpaced(numSamples, includeBounds=True)#

Returns a filtered set of loads. Try to evenly space the output steps There should not be any contact frames

includeBounds == False will give evenly spaced time steps, but may or not not include the start/end time

includeBounds == True will include the start/end time but loads will not not be exactly evenly if the numSamples does not divide evenly into the number of timeSteps. In this case we try to get as evenly spaced as possible

peaks(peaksPerComp=5, components='FX FY FZ FM TX TY TZ TM', forceThreshold=1e-05, torqueThreshold=0.001)#

Returns a filtered set of loads. For each joint, ‘peaksPerComp’ peaks are gathered per requested component. The consolidated list of these values are returned removing duplicates.

The values at the start and end times are considered peaks since they might be a min/max value.

Peaks whose absolute value is < forceThreshold / torqueThreshold (in base units) are ignored

timeSlice(start=None, end=None)#: Get all time steps between a start and end time inclusive

copy(items=None)#: Create a copy of self containing the passed items