fe-safe/True-Load™ is an Abaqus CAE plug-in that allows seamless integration of Abaqus results and loading data into fe-safe™. It manages complex loads over the entire loading event by coupling the FEA model with measured strain data.
fe-safe/True-Load™ uses the data from a handful of strain gauges to understand the structural response of the entire model. This type of knowledge is critical to understanding the loading environment on structures and performing accurate fatigue calculations. fe-safe/True-Load™ offers unparalleled in-situ load calculation with typical strain gauge correlation to within 2% of measured values. True-Load/Post-Test produces multi-channel data files, load definition files (LDF) and fe-safe™ macros.
Complex structures can go from strain gauge measurement to FEA fatigue results with unparalleled accuracy in a matter of minutes.
fe-safe/True-Load™ turns complex components into multi-channel load cells. Working with finite element models, it optimises the location of strain gauges on a component. After strain measurement in the field, it then calculates the time histories of each individual applied load. These loading histories can be used for laboratory testing, or applied as loads in a fatigue-from-FEA analysis.
The FEA strains will match the measured strains with unprecedented accuracy.
Historically, predicting fatigue life has been challenging because even simple structures undergo complex loading. Many engineering organisations rely on historical data or multi-body dynamics models for loading profiles, often without correlation to the FEA model. The accuracy of the fatigue prediction is directly related to the accuracy of the loading profile. Uncorrelated loading profiles will lead to incorrect fatigue calculations. Even small errors in loading knowledge can lead to large errors in fatigue life prediction because of the log-log nature of fatigue life models.
With fe-safe/True-Load™ the unknowns in loading are eliminated.
fe-safe/True-Load™ is ideal for components subject to complex enviromental loading such as:
For complex structures and components fe-safe/True-Load™ provides a unique capability to understand the entire loading event by coupling the FEA model and measured strain data. fe-safe/True-Load™ leverages the model for:
Images courtesy of Dassault Systèmes' SIMULIA brand
Structures undergo elastic deformation due to a wide range of loading combinations. By using user-defined unit load cases, fe-safe/True-Load™ searches the FEA model for gauges that best satisfy the equation: [ε][C]=[F]
The load proportionality matrix [C] is calculated from virtual gauge locations in the FEA model via: [C]=[εTε]-1εT
While a large number of possible strain gauge locations are possible, the load proportionality matrix [C] found by fe-safe/True-Load™ is mathematically the most robust relationship in the FEA model. This guarantees a strain correlation with remarkable accuracy – typically within 2% for every strain channel.
In addition to the scale-and-combine event creation in fe-safe®, the loading time histories are also organised into 'quasi-static event' files (.qse) for post-processing in Abaqus CAE. The quasi-static functionality allows the analyst to create XY plots for any node or element in the model. Full-field results for any subset of the time domain are also available.