Update

Publications, Presentations & Others

UPDATE: 2020-05

One of my students, Jiacheng Liu, was selected as the 2019 ISD outstanding Capstone Award Winner, for her work of applying parametric FE brain models to study effects from head morphological variation on brain impact responses in sports-related concussion. Congratulations, Jiacheng!

UPDATE: 2019-08

I attended the 2019 Ground Vehicle Systems Engineering and Technology Symposium (GVSETS) at Novi, MI , where I gave a presentation on "Seatbelt-Mounted Airbag Design For Occupant Protection In Tactical Vehicles During Frontal Crashes". This study was funded by US Army Ground Vehicles Systems Center (GVSC) in Warren, MI.

Through sled tests and computational simulations, this study demonstrated the benefit of adding a properly designed seatbelt-mounted airbag to improve the occupant protection in frontal crashes under an environment representing a light tactical vehicle.

Left: Baseline 3-point belt
Right: 5-point belt with shoulder airbags and a hybrid bag

UPDATE: 2019-06

I attended the 2019 ESV Conference at Eindhoven, the Netherlands, where I gave a presentation on "Frontal Crash Simulations Using Parametric Human Models Representing a Diverse Population".

Funded by the General Motors, this study used a large set of FE human models (n=103) with a wide range of age, stature and body shape for men and women for US-NCAP frontal crash simulations considering driving posture variations due to occupant attributes. The simulations suggested that driver stature and body shape affect occupant interactions with the restraints, occupant kinematics, and injury risks in severe frontal crashes, while driver age affects the human tolerance and in turn affects driver injury risks. U-shaped relations between occupant stature/weight and head injury risk were observed. Chest injury risk was strongly affected by age and sex, with older female occupants having the highest risk. A strong correlation was also observed between BMI and knee-thigh-hip injury risk.

Effects from human factors on driver injury risks in frontal crashes

UPDATE: 2019-04

I attended the 2019 SAVIR Conference at Cincinnati, OH, where I gave a talk on "Toward Reliable Assessment of Concussion: A Study on Head Finite Element Models Considering Human Variability".

This study was funded by the University of Michigan Injury Prevention Center for developing parametric head FE models accounting for geometric variations in the young population, and using a diverse set of head models to evaluate the effects of morphological variations in human skull on brain tissue impact responses.

Strain distribution in the brain of a 25 YO Male in a concussive impact

UPDATE: 2019-02

I attended the DoD Working Group meeting on Computational Modeling of Human Lethality, Injury, and Impairment from Blast-related threats, at MITRE Corporation, Mclean, VA, and gave a talk on "An Efficient Parametric Finite Element Human Body Model to Assess Protection for a Diverse Population".

This study was funded by Air Force Research Lab for developing a new parametric FE human body model.

Morphed Human Models Representing Various Postures

UPDATE: 2018-09

I attended the 2018 IRCOBI Conference at Athens, Greece, where I presented a paper "A New Prototype 4-Point Seatbelt Design to Help Improve Occupant Protection in Frontal Oblique Crashes". This study was funded by NHTSA.

Using sled tests and computer simulations, this study demonstrated that a suspender 4-point belt has the potential to improve passenger protection, including measured reductions in the head and chest injury values, in frontal oblique crash conditions.

Occupant Kinematics in frontal oblique crash condition

Left: Baseline 3-point belt Right: 4-point suspender belt

UPDATE: 2018-07

I attended the 2018 World Congress on Computational Mechanics at NYC, where I chaired a session on "Computational Biomechanics of Impact and Injury", and gave a presentation entitled "Automated, Component-based Mesh Morphing for Parametric Finite Element Human Modeling ".

This study is primarily based on my student, Abeselom Fanta's work on morphing the GHBMC detailed midsize male model into 12 male occupants with a wide range of age, stature, and weight. Based on the impact simulations under six loading conditions, we found that the traditional scaling method is not adequate to account for the body shape effects on human impact responses, especially for conditions involved loading through a lot of soft tissues. Parametric human models can provide tools for future safety designs by accounting for human variations.

Morphed Human Models Representing a Diverse Population

UPDATE: 2018-06

I was invited to give a talk entitled "Developing and Validating Individualized Human Body Models by Morphing THUMS" at the 2018 THUMS USA Users' Meeting in Dearborn, MI.

In the past five years, my students, post-docs, colleagues, and myself have been gathering data and developing methods to enable a major change in how FE human models are developed, validated, and used. This presentation highlighted the recent advances in parametric human modeling that allows the size and shape of the midsize male THUMS model to be rapidly varied, and subject-specific model validations against PMHS impact tests with a wide range of stature and body shape.

Subject-specific Human Model Validation against Testing Results from a Short, Old, and Lean PMHS (Hwang et al. 2016)

UPDATE: 2018-04

I attended the 2018 SAE World Congress at Detroit, MI, where I chaired a session on "Occupant Protection: Integrated Safety Systems", and gave a presentation entitled "Optimizing Occupant Restraint Systems for Tactical Vehicles in Frontal Crashes".

The presented study was funded by the US Army TARDEC through the Automotive Research Center, We conducted sled testing, computational modeling, and design optimizations, and demonstrated the benefit of adding properly designed airbags and advanced seat belt features to improve occupant protection in an environment representing a light tactical vehicle.

Midsize male ATD with body-borne gear in frontal crashes

UPDATE: 2017-11

I attended the Stapp Car Crash Conference at Charleston, SC, where I gave a presentation entitled "Optimizing Seat Belt and Airbag Designs for Rear Seat Occupant Protection in Frontal Crashes".

This NHTSA-funded study is the most comprehensive study in the literature for rear-seat restraint designs in frontal crashes. It highlighted the potential benefit of using advanced seatbelt (e.g. pre-tensioner and load limiter) and airbag systems for rear-seat occupants.

HIII 5th female ATD kinematics with 3 restraints and 2 pulses

UPDATE: 2017-09

I attended the SAVIR 2017 Conference at Ann Arbor, MI, where I gave a presentation entitled "A New Pediatric Head Injury Assessment Tool for Possible Child Abuse Cases Considering Subject-specific Child Head Anatomy". This study was funded by National Institute of Justice.

In this study, we developed a parametric head FE model for 0-3 year-old children; reconstructed 50 cadaver tests from Weber's study; collected 60 pediatric fall cases with in-depth investigations; and reconstructed those cases using the computational human models. The modeling paradigm will provide a more objective, accurate, and cost-effective way for future forensic investigations to evaluate the consistency of a head injury with the stated cause in an infant or a young child.

Parametric Head FE Model of 0-3 Year-old Children

UPDATE: 2017-09

I attended the 2017 IRCOBI Conference at Antwerp, Belgium, where I gave a presentation entitled "Stature and Body Shape Effects on Driver Injury Risks in Frontal Crashes: A Parametric Human Modelling Study". This presentation is based on Kai Zhang's work at UMTRI supported by GM.

This study suggested that driver body size and shape affect occupant interactions with the restraints, occupant kinematics, and injury risks. Therefore, restraint optimization should include additional consideration of occupants who differ substantially in size and shape from the ATDs commonly used for vehicle assessment.

Stature and obesity effects on occupant impact responses

Update: 2017-07

I attended the 14th U.S. National Congress on Computational Mechanics in Montreal, Canada, where I gave a presentation entitled "Comparing adult ribcage geometries between populations in the United States and China". This presentation is based on Dr. Peiyu Li's Ph.D. dissertation work at UMTRI.

Although my colleagues and I have worked on developing statistical human geometry models for several years, this is our first study that human geometries between populations in two countries were compared. The results demonstrated that age, sex, stature, and BMI effects on ribcage size and shape are similar between the U.S. and Chinese subjects, but U.S. subjects had significantly thicker rib cortical bone than the Chinese subjects.

Age effects on ribcage shape and rib angle between U.S. and Chinese populations

Update: 2017-06

I attended the 25th International Technical Conference on the Enhanced Safety of Vehicle (ESV) in Detroit, where I gave two presentations.

Hu J, Klinich KD, Manary MA, Flannagan CAC, Narayanaswamy P, Reed MP, Andreen M, Neal M, Lin C (2017) "Does Unbelted Safety Requirement Affect Protection For Belted Occupants" Traffic Injury Prevention, 18(S1): S85-S95. [ESV peer-reviewed paper]

This paper was based on a large-scale study funded by NHTSA and conducted collaboratively with General Motors. Seatbelt interlock technologies have been allowed and can potentially increase the seatbelt use rate to nearly 100%. However, FMVSS 208 regulation still requires vehicles to be tested with unbelted crash dummies. This study conducted thousands of FE crash simulations along with field data analysis, and found that if the unbelted crash requirement is removed, the protection of belted occupants may be improved in certain crash conditions. This finding highlighted the need to re-visit the unbelted requirement when the seatbelt interlock becomes widely available.

Hu J, Zhang K, Fanta A, Hwang E, Reed M. (2017) “Effects of Male Stature and Body Shape on Thoracic Impact Response Using Parametric Finite Element Human Modeling” 25^th ESV, Detroit, MI.

Over the past several years, our group has developed automated methods for rapidly morphing the size and shape of FE human models used for crash simulations. This study was the first to morph both widely used detailed models of midsize male occupants, from the THUMS and GHBMC families. The results demonstrate the utility of being able to separate true anatomical effects from the differences between models.

Optimizations based on dummy impact simulations with and without unbelted requirements

GHBMC and THUMS midsize male models were morphed into other body sizes and shapes

Update: 2017-06

One of my students, Kai Zhang, published a paper at the Journal of Biomechanics in June 2017, and the paper was highlighted on the Journal homepage for issue BM 60. Congratulations!

Zhang K, Cao L, Fanta A, Reed MP, Neal M, Wang JT, Lin CH, Hu J (2017) “An Automated Method to Morph Finite Element Whole-body Human Models with a Wide Range of Stature and Body Shape for both Men and Women” Journal of Biomechanics, 60: 253-260.

This study improved our previous mesh morphing method for rapid development of FE human models to represent a diverse population. More importantly a large set of morphed human models were used for impact simulations, which demonstrated the necessity of considering the population variation in evaluating the occupant injury risks.

Large variations in pendulum chest impact responses among the population

Update: 2017-04

I attended the 2017 SAE World Congress in Detroit, where I presented a study on a new dynamic rollover testing method.

Hu J, Orton N, Gruber R, Hoover R, Tribbett K, Rupp J, Clark D, Scherer R, Reed M. (2017) “Development of A New Dynamic Rollover Test Methodology for Heavy Vehicles” SAE 2017 World Congress, SAE-17SS-0272, Detroit, MI.

Among all the vehicle rollover test procedures, the SAE J2114 dolly rollover test is the most widely used. However, it requires the test vehicle to be seated on a dolly with a 23° initial angle, which makes it difficult to test a vehicle over 5,000 kg without a dolly design change, and repeatability is often a concern. In this study, we developed and implemented a new and innovative dynamic rollover test methodology that can be used for evaluating vehicle crashworthiness and occupant protection without requiring an initial vehicle angle. Thanks the Center for Advanced Product Evaluation (CAPE) for conducting these tests for us.

Update: 2017-01

Two papers from our group were published online by Traffic Injury Prevention in January 2017.

Klein KF, Hu J, Reed MP, Schneider WL, Rupp JD (2017) "Validation of a Parametric Finite Element Human Femur Model" Traffic Injury Prevention, 18(4): 420-426

This study was based on Dr. Katelyn Klein's PhD dissertation work at UMTRI, in which subject-specific FE femur models were rapidly developed and validated against data from multiple cadaveric femur bending tests. Traditional model validation process relies on testing corridors developed by scaling the cadaver impact responses to the midsize male stature and weight. Because parametric human models can represent human with a wide range of characteristics, subject-specific model validations are needed to fully evaluate their accuracy. This study demonstrated that the parametric femur model can reasonably account for the differences in impact responses caused by the morphological variations among the subjects.

Zaseck LW, Orton N, Chen C, Rupp J, Reed M, Gruber R, Scherer R, Hu J (2017) "The Influence Of Personal Protection Equipment, Occupant Body Size, and Restraint System on the Frontal Impact Responses of Hybrid III ATDs in Tactical Vehicles" Traffic Injury Prevention, 18(6): 642-649.

My colleague, Dr. Lauren Zaseck, has led the publication based on our recent work aimed at improving crash protection for soldiers in tactical vehicles. In this project, funded by the US Army TARDEC through the Automotive Research Center, we conducted a series of sled tests to assess the performance of various restraint systems. Three sizes of Hybrid-III ATDs were used along with a range of body armor and body borne gear configurations. The results demonstrated that achieving good restraint performance with soldiers in military gear is challenging and quite different to conditions associated with civilian passenger cars. Nevertheless, we found that advanced seatbelt features such as pre-tensioners and load limiters substantially improve protection for ATDs with military gear.

Subject-specific model validation example

Occupant kinematics with different restraint configurations

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