Recent Graduates


Zhaonan Sun (PhD)

Dr. Sun has over 8 years’ experience in the biomechanical experiments and simulations. Dr. Sun received his B.Sc. in Biomedical Engineering from the Hong Kong Polytechnic University in 2014, where he gained extensive research experience in orthopedic biomechanics and gait analysis. After a one-year research assistant appointment in Hong Kong, he joined the Center for Applied Biomechanics (CAB) as a PhD student advised by Dr. Jason Kerrigan in 2015. Dr. Sun’s graduate research at the CAB has mainly focused on mechanical characterization and computational modeling of human subcutaneous adipose tissue, with the goal of improving current finite element human body models. He has also led various biomechanics-related projects, including mechanical characterization of the human knee joint and human cortical bone. In spring 2021, Dr. Sun defended his dissertation and graduated with a PhD in Mechanical and Aerospace Engineering at the University of Virginia. His dissertation work has led to the creation of the first series of human adipose tissue constitutive and computational models which can be used to simulate adipose tissue mechanical responses under motor vehicle crash related conditions. This work is available in several peer-reviewed scientific publications.

After earning his PhD, Dr. Sun joined Align Technology, Inc as an R&D Engineer - Simulation & Modeling.





Kevin Kong (PhD)

Dr. Kong’s experience has been focused on soft tissue biomechanics during his time at the Center for Applied Biomechanics (CAB) from 2016-2020, under his advisor Dr. Matthew Panzer. His graduate research combines experimental and computational mechanics to develop both biological and engineering materials Finite Element (FE) models to aid in investigating human body response, including injuries under severe impacts in sports, automotive and military incidents. He has also participated in various biomechanics-related projects, including quantifying seat angles for occupants in autonomous vehicles and developing a human dummy computational model for an American football helmet assessment. In 2020, Dr. Kong defended his dissertation and graduated with a PhD in Mechanical and Aerospace Engineering at the University of Virginia. His dissertation work has led to the creation of sub tissue computational models that can be used to simulate human skin failure as a result of ballistic blunt impacts. In addition, his research outcome has also been utilized to support the development of biofidelic skin simulants.

After earning his PhD, Dr. Kong joined Ansys, Inc as an Application Engineer.

Dissertation: Development of a Computational Model of Skin Damage under Blunt Impact to Investigate Skin Failure Threshold



Daniel Perez Rapela (PhD)

Dr. Perez-Rapela has over 10 years’ experience in the field of injury biomechanics and passive safety, with a special interest in vehicle occupant protection, Human Body Models (HBMs) and machine learning. After graduating with a BS+MS in Industrial Engineering at the University of Zaragoza in 2010, Dr. Perez-Rapela joined IDIADA and later the VW-Group where he led the development of multiple vehicles as lateral occupant protection leader in the simulation department of SEAT. Dr. Perez-Rapela graduated with a PhD in Mechanical and Aerospace Engineering from the University of Virginia in 2020, where he holds a post-doctoral researcher position. During his research career, Dr. Perez-Rapela has, among other contributions, developed procedures for the full automation of HBM simulation and morphing, and integrated machine learning techniques in the field of injury biomechanics. These contributions to the field of computational biomechanics have enabled him to develop methodologies for the stochastic analysis of vehicle safety taking into account human and non-human variability, and modeling uncertainty. His work, which includes multiple PMHS tests and HBM simulations, is available in several peer-reviewed scientific publications.

After earning his PhD, Dr. Perez Rapela joined UVAs Center for Applied Biomechanics as a Research Associate.

Dissertation: Methodology for the Evaluation of Human Response Variability to Intrinsic and Extrinsic Factors Including Uncertainties


Carolyn Roberts (PhD)

With seven years’ experience with injury biomechanics research, Dr. Roberts leads the UVA-CAB’s efforts in developing injury prediction tools for the female population. This includes fundamental research on the roles of sex-related geometric, material, and hormonal factors on differences in biomechanics and injury susceptibility between male and females. Her work has been applied to investigate the validity of standard scaling practices for translating between male and female response, and the factors warranting generation of new biomechanical data specifically for females. In addition to this fundamental work, Dr. Roberts has led the UVA-CAB’s efforts in generating female cadaveric data, biofidelity corridors, and injury risk functions for the 5th percentile female THOR lower extremities. Recently her work has focused on field data analysis for injury risk factor evaluation across age and sex, analysis of biofidelity of female injury prediction surrogates, and quantification of belt fit and restraint effectiveness across different external body shapes and skeletal alignment.

After earning her PhD, Dr. Roberts joined UVAs Center for Applied Biomechanics as a Research Associate.

Dissertation: Sex-based Geometric Differences in the Lower Extremity and their Effect on Injury in the Automotive Crash Environment


Benjamin Igo (MS)

Ben performed his research at the UVA Center for Applied Biomechanics from Fall 2018-Spring 2020 under Dr. Matthew Panzer. His research focused on investigating the mechanical and morphological properties of the pediatric skull to aid in treating pediatric craniofacial pathological conditions. This research consisted of two phases. First, mechanical tests and micro-CT scans were performed on pediatric cranial bone obtained from surgical procedures to understand its microstructure and mechanical properties. Second, an analytical model was developed to model growth of the developing pediatric skull to investigate the impact of tissue growth parameters on the predicted pediatric skull shape, mechanical properties, and thickness. The combined insight from this work will help to address the underlying challenges associated with pediatric craniofacial surgeries so that the overall well-being of pediatric surgical patients can be collectively maximized moving forward.

Since earning his MS, Ben joined Corvid Technologies as a Computational Analyst, working on a wide variety of simulation and modeling projects.

Thesis: Understanding the Mechanical and Morphological Properties of the Pediatric Skull




Varun Bollapragada (PhD)

Dr. Bollapragada has 9 years of experience in the field of biomechanics and automotive safety. His doctoral research is focused on understanding the influence of the long terms effects of disability associated with injuries on vehicle design in the context of pedestrian safety. He is an expert in multibody modeling and his notable accomplishments include development of multibody models of a sedan and SUV to study pre-ballistic maneuvers in rollover crashes, and a multibody human model representing a 50th percentile male which has been used by OEM’s in improving their vehicle design for pedestrian safety. He has also performed many modeling studies using finite element and multibody human models to assess and improve biofidelity. He has used computational models for sensitivity analysis using design of experiments and Monte Carlo Analysis. He has performed component-level and whole-body cadaveric and ATD tests to develop response corridors and to evaluate biofidelity. His current research interests include subject specific finite element model development from CT scan data using morphing techniques.

After earning his PhD, Dr. Bollapragada joined UVAs Center for Applied Biomechanics as a Research Associate.

Dissertation: The Influence of Disabling Injuries on the Design of the Vehicle Front End for Pedestrian Safety


Ryan Neice (MS)

Ryan fulfilled his graduate research requirements at UVA’s Center for Applied Biomechanics from 2017-2019, under his advisor Dr. Matthew Panzer. His graduate research focused on developing an injury predictive pelvis finite element model for lateral dynamic loading. The force response and injury predictions of the pelvis FE model were validated with cadaveric pelvis tests performed at UVA. A simulation matrix was then constructed, leading to an injury threshold analysis, to determine whether anterior or posterior pelvis force could better predict pelvis fracture. Using injury risk functions constructed from simulation data, it was determined that posterior pelvis force was a superior injury prediction metric, suggesting that future side impact ATD designs include posterior pelvis load cells. In addition to his thesis, Ryan worked on other side projects during his time at CAB including: modeling lower extremity response during under body blast loading, testing computational methods to simulate tissue pretensioning, cadaver PMHS experiments, and constitutive modeling.

Since earning his M.S., Ryan has joined the US Army Research Laboratory as a Biomechanical Engineer, evaluating the protection capabilities of current military helmet designs and developing improved protection strategies against TBI-inducing blunt impact.

Thesis: Development and Validation of a Pelvis Finite Element Model for Side Panel Intrusion Threats



Jacek Toczyski (PhD)


Dr. Toczyski has over 8 years of experience in the field of biomechanics and automotive safety and more than 10 years of experience in the field of computational mechanics. He graduated with Master’s degree from the Warsaw University of Technology (Warsaw, Poland). In 2019, he defended his PhD dissertation at the University of Virginia Center for Applied Biomechanics. His doctoral research was focused on motion prediction based on the data obtained from inertial sensors. During his stay at UVa, Dr. Toczyski was also involved in projects related to occupant safety in rollover crashes, in development and evaluation of new crash test dummies, and in material characterization of hard tissue.

After earning his PhD, Jacek joined the passive safety team at Tesla, Inc. (Tesla Crash Lab)

Dissertation: 3D Trajectory Calculation in Crash Testing Using Inertial Sensors