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Publications

As a result of our ongoing research program, Intech Engineering’s scientific papers have appeared in numerous prestigious engineering and law journals, including Society of Automotive Engineers (SAE) Review, The Lawyers Weekly, WSTLA Trial News, and The Verdict.

The SAE website allows users to download the following publications:

“Relationships Between Pre-Skidding and Pre-Braking Speed” SAE #2001-01-1281.

The accuracy of vehicle pre-braking speed estimates, based upon tire/roadway coefficient of friction (drag factor) measurements and skid mark measurements, was assessed. Braking tests were performed on three vehicles and a correlation between the calculated pre-skidding speed and the actual pre-braking speed was established.

“Real World Walking Speeds of Young Pedestrians” SAE #2001-01-0897.

Unaware elementary school children were monitored when crossing at marked crosswalks adjacent to elementary schools. The pedestrians’ constant walking speeds were ascertained and categorized according to gender, estimated age, number of pedestrians in a group, and time of day. The observed trends were compared to data from existing studies.

“Knee and Hip Displacements of Vehicle Occupants Restrained by Seat Belts in Frontal Impacts“ SAE #2001-01-0180.

An efficient method to determine the expected forward knee and hip displacements of automobile occupants who are restrained by seat belts during frontal impacts was derived. The results of this study may be referenced to model the lower body motion of vehicle occupants in frontal impacts for a range of impact severities.

“Revision and Validation of Vehicle/Pedestrian Collision Analysis Method” SAE #2002-01-0550

This paper presents a practical analytical approach for evaluating vehicle impact speed from the post-impact vehicle damage, pedestrian injuries and pedestrian throw distance. The applicability of this method to reconstructing real world vehicle/pedestrian collisions is also examined.

“Comprehensive Analysis Method for Vehicle/Pedestrian Collisions” SAE #2000-01-0846… This paper has been revised and updated….we recommend using SAE # 2002-01-0550

A comprehensive method for assessing the vehicle impact speed in a vehicle/pedestrian collision was derived. Mathematical models, real world collision data, and staged impact test data were referenced from over sixty studies pertaining to pedestrian collisions. A practical analytical approach for evaluating vehicle impact speed from the post-impact vehicle damage, pedestrian injuries and pedestrian throw distance was developed.”

“Maximum Head Displacement of Vehicle Occupants Restrained by Lap and Torso Seat Belts in Frontal Impacts” SAE #1999-01-0443.

An efficient method to determine the expected forward head excursion of automobile occupants who are restrained by lap and torso seat belts during frontal impacts was derived. The results of this research can be applied to the assessment of seat belt use by occupants involved in frontal motor vehicle collisions.

“Characteristic Vehicular Deceleration for Known Hazards” SAE #1999-01-0098.

The deceleration of motor vehicles during routine stops for expected hazards in the real world environment was quantified. A mathematical model was developed to define deceleration profiles and yield predictive relations for assessment of velocity, position, and remaining braking time for decelerating passenger vehicles.

“Practical Analysis Technique for Quantifying Sideswipe Collisions” SAE #1999-01-0094.

Sideswipe collisions involve the surface of one vehicle sliding along another vehicle or object. A comprehensive analytical approach for evaluating the severity of this type of vehicular collision was developed. Several series of sideswipe collisions were staged to validate the analysis model.

“Lane Change Maneuver Modeling for Accident Reconstruction Applications” SAE# 2002-01-0817.

Lane change maneuvers are often implemented in typical driving applications and more severe swerving maneuvers are occasionally performed in order to avoid motor vehicle collisions. For accident reconstruction purposes, it is necessary to accurately model the vehicle motion and driver response during a lane change maneuver. A theoretical lane change model was developed in order to determine the expected vehicle dynamics including lateral, longitudinal and angular vehicle displacements during the lane change maneuver. This model is based on the vehicle speed, peak and average accelerations, and driver steering input. The theoretical model was then compared to a limited number of real world staged lane change maneuvers conducted with instrumented vehicles over a small range of speeds, accelerations and displacements. The lane change model was found to closely simulate the vehicle motion as recorded during the staged tests. The derived lane change model was also compared to existing models and statistical comparisons were conducted.

“Theoretical vs. Empirical Solutions for Vehicle/Pedestrian Collisions” SAE# 2003-01-0883

There are many mathematical and empirical models to facilitate technical analysis of vehicle-pedestrian collisions. The main objective of the technical analysis is to determine the vehicle impact speed. In the real world, post-impact data from vehicle/pedestrian collisions is often insufficient to use pure mathematical models. However mathematical models can be utilized successfully with the aid of some empirical data or reasonable assumptions. Conversely the empirical models overcome the difficulty of insufficient data, but must be applied within the model defined limits. This study compares the mathematical and empirical models.

“Head, Hip and Knee Velocities of Restrained Occupants in Frontal Impacts”  SAE # 2003-01-0884

This study presents an efficient method for forensic engineers to determine the maximum forward head, hip and knee velocities of automobile occupants who are restrained by seat belts during frontal impacts. The ratios of the peak head, hip and knee velocities as a function of the impact speed change were determined from a combination of previous research data. The time and location at which the peak velocities occur are also presented. In addition, the head velocity profile as a function of head displacement was quantified for the lap and torso restraint case. The compiled head, hip and knee velocities may be utilized in order to assess seat belt usage and benefit. The results of this study may be referenced to aid in modeling the motion of vehicle occupants in frontal impacts for a range of impact severities.

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