A Comprehensive Metric for Comparing Time Histories in Validation of Simulation Models With Emphasis on Vehicle Safety Applications

Abstract

Computer modeling and simulation are the cornerstones of product design and development in the automotive industry. Computer-aided engineering tools have improved to the extent that virtual testing may lead to significant reduction in prototype building and testing of vehicle designs. In order to make this a reality, we need to assess our confidence in the predictive capabilities of simulation models. As a first step in this direction, this paper deals with developing a metric to compare time histories that are outputs of simulation models to time histories from experimental tests with emphasis on vehicle safety applications. We focus on quantifying discrepancy between time histories as the latter constitute the predominant form of responses of interest in vehicle safety considerations. First we evaluate popular measures used to quantify discrepancy between time histories in fields such as statistics, computational mechanics, signal processing, and data mining. Then we propose a structured combination of some of these measures and define a comprehensive metric that encapsulates the important aspects of time history comparison. The new metric classifies error components associated with three physically meaningful characteristics (phase, magnitude and topology), and utilizes norms, cross-correlation measures and algorithms such as dynamic time warping to quantify discrepancies. Two case studies demonstrate that the proposed metric seems to be more consistent than existing metrics. It is also shown how the metric can be used in conjunction with ratings from subject matter experts to build regression-based val- * Corresponding author, Phone/Fax: (734) 615-8991/647-8403 idation models.

Finite Element Model of the THOR-NT Dummy under Vertical Impact Loading for Aerospace Injury Prediction: Model Evaluation and Sensitivity Analysis

“…HIC 15 values are shown to be primarily sensitive to head rotation angle in all three simulations (Fig. 12).…”

“…The largest test value of HIC 15 (18.28), seen during the 2012-3 pulse, is 2.61% of the injury limit. In addition, the largest simulation value of HIC 15 (16.26) exhibited during the 2012-1 pulse is 2.32% of the injury limit (700).…”

“…Time intervals ( t) of 15 and 36 ms were used to calculate the HIC 15 and HIC 36 , respectively. Established injury thresholds for a midsize male dummy are 700 and 1000 for the HIC 15 and HIC 36 ,…”

“…12) have focused on developing a systematic methodologies for model evaluations (Refs. [13][14][15][16][17], particularly for impact tests where a large number of channels must be compared. Though the final system has yet to be released (Ref.…”

Development, Calibration, and Validation of a Head–Neck Complex of THOR Mod Kit Finite Element Model

“…Recently, there have been several efforts focused on developing systematic methodologies for model evaluations (Gehre et al 2009;Hovenga et al 2004;Jacob et al 2000;Sarin et al 2008;, especially in impact tests where a large number of channels must be compared. These approaches evaluate the response of the model in comparison to test data based on defined correlation metrics, which allow a quantitative evaluation of the model response.…”