Guanjun Zhang

Hunan University · State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body

Craniocerebral injury has been a research focus in the field of injury biomechanics. Although experimental endeavors have made certain progress in characterizing the material behavior of the brain, the temperature dependency of brain mechanics appears to be inconclusive thus far. To partially address this knowledge gap, the current study measured t...

Most current vision-based fatigue detection methods don’t have high-performance and robust face detector. They detect driver fatigue using single detection feature and cannot achieve real-time efficiency on edge computing devices. Aimed at solving these problems, this paper proposes a driver fatigue detection system based on convolutional neural ne...

The 0.2% strain offset approach is mostly used to calculate the yield stress and serves as an efficient method for cross-lab comparisons of measured material properties. However, it is difficult to accurately determine the yield of the bone. Especially when computational models require accurate material parameters, clarification of the yield point...

The bending fracture behaviors of long bone have gained great attention due to the high bending fracture risk during traffic accidents, etc. For evaluating bone bending behavior, most of the previous studies use an impactor in 3-pints bending experiments while the impactor rigidity was never considered. In this work, using the porcine long bones, t...

The aim of this study is to design a novel, high-efficiency and low-cost Bilateral Pretensioner (BLP) and evaluate it using a computational approach, i.e. coupling of FEA and multibody dynamics. The BLP system was designed by changing the rotation axle of the conventional retractor. The computational models for BLP, and the other two designs, namel...

Convolutional neural networks (CNNs) exhibit excellent performance on the head pose estimation problem under controllable conditions, but their generalization ability in the wild needs to be improved. To address this issue, we propose an approach involving the introduction of facial landmark information into the task simplifier and landmark heatmap...

Literature has reported controversial findings on whether formalin affected bone properties, or not, especially when different preservation time durations and temperatures were involved. Hence, accurately and systematically quantifying the effect of formalin on the mechanical properties of bone using a large dataset is crucial for assessing biomech...

The objective of this research was to study the physiological performance of young novice male drivers after they were administered different doses of alcohol. The physiological performance of drivers under the influence of alcohol (DUI) was compared with that of drivers not under the influence of alcohol (non-DUI). After the administration of alco...

Background: The use of saline in preserving bone specimens may affect the mechanical properties of specimens. Yet, the reported effects varied and contradicted to each other, with a lack of investigating constitutive material parameters. Therefore, we quantified the effects of preservation time on the constitutive properties of cortical bone. Met...

Although the beam theory is widely used for calculating material parameters in three-point bending test, it cannot accurately describe the biomechanical properties of specimens after the yield. Hence, we propose a finite element (FE) based optimization method to obtain accurate bone material parameters from three-point bending test. We tested 80 ma...

Background The number of sport utility vehicles (SUVs) on China market is continuously increasing. It is necessary to investigate the relationships between the front-end styling features of SUVs and head injuries at the styling design stage for improving the pedestrian protection performance and product development efficiency. Methods Styling feat...

Acquisition of accurate and reliable constitutive parameters related to bio-tissue materials was beneficial to improve biological fidelity of a Finite Element (FE) model and predict impact damages more effectively. In this paper, a femur FE model was established under multiple loading conditions with diverse impact positions. Then, based on sequent...

A lower limb-pelvis finite element (FE) model with active three-dimensional (3D) muscles was developed in this study for biomechanical analysis of human body. The model geometry was mainly reconstructed from a male volunteer close to the anthropometry of a 50th percentile Chinese male. Tissue materials and structural features were established based...

Accurate material parameters are critical to construct the high biofidelity finite element (FE) models. However, it is hard to obtain the brain tissue parameters accurately because of the effects of irregular geometry and uncertain boundary conditions. Considering the complexity of material test and the uncertainty of friction coefficient, a comput...

The lower extremity of the human body is one of the most vulnerable parts in traffic accidents,and the finite element (FE) model of the lower limb has become an important tool to study mechanisms and protective methods of lower limb injuries.In order to ensure the fidelity of the model,it is necessary to carry out a comprehensive validation under m...

In this paper the effects of seat parameters on its occupant protection performance in frontal crash are studied. Firstly a simplified sled test device for restraint system is designed based on the relevant dimension of front passenger seat of a car, and a finite element simulation model for restraint system with Hybrid III 50th percentile dummy is...

The finite element method has become an important means of injury biomechanics, accurate cortical bone material constitutive parameters are important for the study of human impact injury and artificial bone. In this study, a method for processing high precision regular specimens is proposed and a quasi-static three-point bending test was applied. T...

Based on the Chinese 50th percentile male lower-leg model developed, the foot model, the model for 11 ankle ligaments and the model for 11 bundles of muscle are added to be used for conducting the study on ankle dynamics characteristics and the simulation on active force. The single-point integration shell element is used to simulate the ankle liga...

Aiming at the occupant seat posture aggravated by AEB, the effectiveness of RPS in improving occupant OOP seating posture was investigated. A numerical simulation approach was utilized to establish a driver-side restraint system model involving AEB, RPS and active human model(AHM). On the basis of volunteer tests which were conducted to obtain the...

The effects of formalin fixation on bone material properties remain debatable. In this study, we collected 36 fresh-frozen cuboid-shaped cortical specimens from five male bovine femurs and immersed half of the specimens into 4% formalin fixation liquid for 30 days. We then conducted three-point bending tests and used both beam theory method and an...

At present, crash dummies and finite element human models are mainly created based on occidental human statistical data, so the differences in biomechanical response caused by the differences in human stature are worth exploring. Establishing the 50th percentile Chinese model is conducive to improving the injury protection level of Chinese people....

Objective: The objective of this research was to study risk factors that significantly influence the severity of crashes for drivers both under and not under the influence of alcohol. Methods: Ordinal Logistic regression was applied to analyze a crash data set involving drivers under and not under the influence of alcohol in China from January 2...

Based on scaling and nonlinear-fitting methods, the material properties of the 3-year old pediatric cervical spine were acquired. A specific scaling method for the mechanical properties of the pediatric cervical ligaments was proposed, and the C4-C5 cervical segment finite element model for the 3-year old child was developed with accurate geometrie...

The objective of this research was to study the performance of young novice male drivers in a driving simulator after they were administered different doses of alcohol (placebo: 0 g/kg; medium dose: 0.75 g/kg; high dose: 1 g/kg) during the blood alcohol concentration (BAC) ascending and descending periods. The high dose of alcohol produced an avera...

Based on the spiral CT scan of lower limbs with major anatomical structures reserved, a lower leg FE model for the Chinese 50th percentile male is established. Model scaling is conducted based on the anthropometry for Chinese with cortical bone thickness accurately simulated, and the tension and compression and strain rate characteristics of cortic...

The combination of passive and active vehicle safety technologies can effectively improve vehicle safety. Most of them predict vehicle crashes using radar or video, but they can't be applied extensively currently due to the high cost. Another collision forecasting method is more economic which is based on the driver behavior and vehicle status, suc...

Injury of the lower limb is one of the most common injuries in vehicle-to-pedestrian crashes. Therefore, accurate Finite Element (FE) models of pedestrian lower limb with high biofidelity play an important role in developing effective research techniques for the protection of the lower limb. The models of lower limb long bones (femur, tibia, and fi...

Based on the thorough validation of the models for the long bones and knee ligaments of lower limbs in previous studies of authors, a FE model for pedestrian knee joint with detailed anatomic structure is developed, and the contact properties among different tissues are defined. According to the biomechanical experiments, which more accord with the...

In this study, the software ANSYS ICEM CFD and HYPERMESH was used to develop a finite element (FE) model for 10-year-old child head with detailed anatomical characteristics. The MADYMO models of crash dummies were used to simulate the dynamic responses of an injured child in a typical falling accident from three different heights, and the motion pa...

Based on the knee ligament model in total human model for safety (THUMS), with material parameters and element properties modified, and using the newer experimental data of biomechanics in recent years, the biofidelities of ligament models under different strain rates are validated one by one. The results indicate that the relation curves of tensio...

FE models are used widely in the pedestrian safety, which has become a very important topic. Based on THUMS model, FE models of femur, tibia and fibula were improved on materials, element properties, and so on. Based on the analysis of loading characteristics of lower limb long bones on pedestrian in vehicle-to-pedestrian crashes, the FE models of...

Synthetic plastic materials were used in the new guardrail considering the shortcoming of the current highway guardrail such as high cost, easy to corrosion and so on. In addition the "sandwich" structure was used to enhance the crashworthiness of the new guardrail. A finite element simulation crash model of highway buses and semi-rigid guardrail w...

Based on THUMS model, the Finite Element (FE) models of thigh and leg were improved on materials, element properties, and so on. The dynamic response of the FE models of thigh and leg was validated against the dynamic 3-point bending tests with different loading locations conducted in a recent study, based on the analysis of loading characteristics...

The head, torso, and lower extremity are the most commonly injured body regions during vehicle-to-pedestrian crashes. A total of 312 cases were selected from the National Automotive Sampling System (NASS) Pedestrian Crash Data Study (PCDS) database to investigate factors affecting the likelihood of sustaining MAIS 3+, AIS 3+ head, AIS 3+ torso, and...