C-NCAP Far Side Protocol 2024 Working Conditions 1-6 SimVT
This topic focuses on the automation of the correlation fitting index assessment using REPORTER. You can also use SimVT to perform the correlation interactively.
Introduction
The C-NCAP Virtual Far Side 2024 protocol requires correlation fitting between simulation and test data to validate the virtual (simulation) models before they can be used to compute an injury score.
The protocol specifies 8 sled test working conditions (i.e. load cases) which must be tested virtually (i.e. Ansys LS-DYNA simulations). C-NCAP will randomly pick one of the working conditions to conduct physical testing and channel data from the selected physical working condition must be correlated with the corresponding virtual working condition and the sensor correlation fitting index scores (a.k.a. sensor scores) must exceed the protocol thresholds in order for the virtual working conditions to be accepted for virtual testing.
This page describes the C-NCAP Far Side Protocol 2024 Working Conditions 1-6 SimVT REPORTER Template which can be used to check the correlation fitting index for Working Conditions 1-6 (i.e. sled model with WSID driver). If you want to check the correlation fitting index for Working Conditions 7 or 8 (i.e. sled model with SIDIIs driver) then please refer to this page.
The C-NCAP Far Side Protocol 2024 Working Conditions 1-6 SimVT REPORTER Template can be run interactively or in batch mode to generate the REPORT and the instructions for running SimVT REPORTER Templates can be found here.
If the template is successfully generated it will show a report summarising the the sensor scores for all the mandatory and monitored channels (listed in C-NCAP Appendix H.1.2.1.3 of the protocol) as well as the correlation graphs for each channel so that you can inspect any channels which perform poorly. Additionally, a SimVT settings file (REPORTER_settings.simvt) is created which can be loaded in to the SimVT workflow tool to interrogate the results interactively.
Before using the REPORTER template with Ansys LS-DYNA data you should have defined the occupant and structures user data required for your model in PRIMER (see Automotive Assessments PRIMER for details).
Report Pages
Page 1 contains a summary of the results for all the assessed and monitored channels. It shows the PASS/FAIL status of the correlation fitting index. The protocol does not require that the "Head acceleration" and "Chest T4 Acceleration" sensor scores exceeds the threshold of 0.7 individually so they are considered as not mandatory. However, there is a requirement that the average sensor score for "Head acceleration", "Head Offset" and "Chest T4 Acceleration" sensors must exceed 0.7. As such although the "Head acceleration" and "Chest T4 Acceleration" sensors fail to meet the threshold, the overall result is still a pass as only mandatory scores affect the PASS/FAIL status.
Page 2-6 show a table of the scores and the corridor plots for each sensor. In the example below the "Head acceleration" sensor is a 3D sensors with X, Y and Z components. The parenthesis around "(FAIL)" and the lighter shade of red indicate that it is not a mandatory requirement for the sensor score to exceed the threshold.
Page 3 shows the head offset correlation. The sensor score is the average of the Y and Z ISO Scores so the weight is 0.5 for both. Passing is mandatory which is communicated by the use of bold green and red colours
The final page of the report contain a table showing the detailed results for each correlation so that they can all be viewed in one place.
