Optimization of Underbody Blast Energy-Attenuating Seat Mechanisms Using Modified MADYMO Human Body Models

2021 ◽  
Author(s):  
Kelly Bosch ◽  
Ann Bailey ◽  
E. Meade Spratley ◽  
Robert S. Salzar ◽  
Paul Begeman ◽  
...  
Keyword(s):  
Human Body ◽  
Dynamic Models ◽  
High Rate ◽  
Human Body Model ◽  
Response Data ◽  
Blast Energy ◽  
Injury Criteria ◽  
Optimal Force ◽  
Spine Injuries ◽  
Human Body Models

Abstract Though energy attenuating (EA) seats for air and spacecraft applications have existed for decades, they have not yet been fully characterized for their energy attenuation capability or resulting effect on occupant protection in vertical underbody blast. EA seats utilize stroking mechanisms to absorb energy and reduce the vertical forces imparted on the occupant's pelvis and lower spine. Using dynamic rigid-body modeling, a tool to determine optimal force and deflection limits was developed to reduce pelvis and lower spine injuries in underbody blast events using a generic seat model. MAthematical DYnamic MOdels (MADYMO) and modeFRONTIER software were leveraged for this study. This optimizing tool may be shared with EA seat manufacturers and applied to military seat development efforts for EA mechanisms for a given occupant and designated blast severity. To optimally tune the EA seat response, the MADYMO Human Body Model (HBM) was first updated to improve its fidelity in kinematic response data for high rate vertical accelerative loading relative to experimental data from laboratory simulated underbody blast tests using post-mortem human surrogates (PMHS). Subsequently, using available injury criteria for underbody blast, the optimization tool demonstrated the ability to identify successful EA mechanism configurations to reduce forces and accelerations in the pelvis and lower spine HBM to presumed non-injurious levels. This tool could be tailored by varying input pulses, force and deflection limits, and occupant size to evaluate EA mechanism designs.

Product Ergonomics Design Driven by Parametric Human Body Model

2011 ◽  
Vol 215 ◽  
pp. 136-143 ◽  
Author(s):  
B. Jiang ◽  
Chun Fu Lu ◽  
Xiao Jian Liu
Keyword(s):  
Human Body ◽  
Design Method ◽  
Structure Design ◽  
Design Parameters ◽  
Surface Model ◽  
Structure Model ◽  
Human Body Model ◽  
Body Model ◽  
Driving Model ◽  
Human Body Models

Considering the demands for product ergonomics design, the paper proposed a driven design method for product’s shape and structure design through the manipulation of human body models. Based on the anthropometry data, a parametric human body driving model system is established with three layers, which are structure model, dimension model and surface model. The driven design method of product ergonomics design is realized, in which human body data are directly mapped to product design parameters. The driven design method provides a rational way to utilize ergonomics design principles and guarantee higher efficiency and more reliability. The method is tested in seat design examples.

scholarly journals Personalization of a Human Body Model Using Subject-Specific Clothing Industry Dimensions

2021 ◽  
Author(s):  
Luděk Hynčík ◽  
Hana Čechová ◽  
Tomasz Bońkowski ◽  
Gabriela Kavalířová ◽  
Petra Špottová ◽  
...  
Keyword(s):  
Human Body ◽  
Injury Risk ◽  
Population Group ◽  
Clothing Industry ◽  
Human Body Model ◽  
Chinese Adults ◽  
Biomechanical Models ◽  
Body Model ◽  
Subject Specific ◽  
Human Body Models

Virtual human body models contribute to designing safe and user-friendly products through virtual prototyping. Anthropometric biomechanical models address different physiques using average dimensions. In designing personal protective equipment, biomechanical models with the correct geometry and shape shall play a role. The presented study shows the variations of subject-specific anthropometric dimensions from the average for the different population groups in the Czech Republic and China as a background for the need for personalized human body models. The study measures a set of clothing industry dimensions of Czech children, Czech teens, Czech adults and Chinese adults and compares them to the corresponding age average, which is represented by a scaled anthropometric human body model. The cumulative variation of clothing industry dimensions increases the farer is the population group from the average. It is smallest for the Czech adults 7.54% ± 6.63%, Czech teens report 7.93% ± 6.25% and Czech children differ 9.52% ± 6.08%. Chinese adults report 10.86% ± 11.11%. As the variations of the particular clothing industry dimensions from the average prove the necessity of having personalized subject-specific models, the personalization of particular body segments using the measured clothing industry dimensions leading to a subject-specific virtual model is addressed. The developed personalization algorithm results in the continuous body surface desired for contact applications for assessing body behavior and injury risk under impact loading.

COMPLIANCE TESTING FOR HUMAN BODY MODEL EXPOSURE TO ELECTROMAGNETIC FIELDS FROM A HIGH-POWER WIRELESS CHARGING SYSTEM FOR DRONES

2020 ◽  
Vol 189 (1) ◽  
pp. 13-27 ◽  
Author(s):  
Jangyong Ahn ◽  
Seon-Eui Hong ◽  
Haerim Kim ◽  
Yangbae Chun ◽  
Hyung-Do Choi ◽  
...  
Keyword(s):  
Electromagnetic Fields ◽  
Human Body ◽  
Internal Electric Field ◽  
Wireless Charging ◽  
Human Body Model ◽  
Case Scenario ◽  
Worst Case ◽  
Charging System ◽  
Compliance Testing ◽  
Human Body Models

Abstract Recently, a wireless charging system (WCS) for drones has been extensively studied, although standards for compliance testing of a WCS for drones have yet to be established. In this study, we propose methods for human exposure assessments of a WCS for drones by comprehensively considering the various positions of the system and the postures of human body models. The electromagnetic fields from a WCS are modeled and the internal quantities of the human body models, consisting of current density, internal electric field and specific absorption rate, are calculated. The incident fields around the WCS and the internal quantities are analyzed at 140 kHz, which is the operating frequency of the WCS applied. Results of an exposure assessment based on the confirmed worst-case scenario are presented. In addition, the internal quantities depending on the human body models and the material characteristics of the simplified models are also discussed using four different anatomical and simplified human body models.

scholarly journals How muscle stiffness affects human body model behavior

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Niclas Trube ◽  
Werner Riedel ◽  
Matthias Boljen
Keyword(s):  
Human Body ◽  
Computation Time ◽  
Material Model ◽  
Muscle Stiffness ◽  
Frontal Impact ◽  
Human Body Model ◽  
Muscle System ◽  
Body Model ◽  
The Past ◽  
Human Body Models

Abstract Background Active human body models (AHBM) consider musculoskeletal movement and joint stiffness via active muscle truss elements in the finite element (FE) codes in dynamic application. In the latest models, such as THUMS™ Version 5, nearly all human muscle groups are modeled in form of one-dimensional truss elements connecting each joint. While a lot of work has been done to improve the active and passive behavior of this 1D muscle system in the past, the volumetric muscle system of THUMS was modeled in a much more simplified way based on Post Mortem Human Subject (PMHS) test data. The stiffness changing effect of isometric contraction was hardly considered for the volumetric muscle system of whole human body models so far. While previous works considered this aspect for single muscles, the effect of a change in stiffness due to isometric contraction of volumetric muscles on the AHBM behavior and computation time is yet unknown. Methods In this study, a simplified frontal impact using the THUMS Version 5 AM50 occupant model was simulated. Key parameters to regulate muscle tissue stiffness of solid elements in THUMS were identified for the material model MAT_SIMPLIFIED_FOAM and different stiffness states were predefined for the buttock and thigh. Results During frontal crash, changes in muscle stiffness had an effect on the overall AHBM behavior including expected injury outcome. Changes in muscle stiffness for the thigh and pelvis, as well as for the entire human body model and for strain-rate-dependent stiffness definitions based on literature data had no significant effect on the computation time. Discussion Kinematics, peak impact force and stiffness changes were in general compliance with the literature data. However, different experimental setups had to be considered for comparison, as this topic has not been fully investigated experimentally in automotive applications in the past. Therefore, this study has limitations regarding validation of the frontal impact results. Conclusion Variations of default THUMS material model parameters allow an efficient change in stiffness of volumetric muscles for whole AHBM applications. The computation time is unaffected by altering muscle stiffness using the method suggested in this work. Due to a lack of validation data, the results of this work can only be validated with certain limitations. In future works, the default material models of THUMS could be replaced with recently published models to achieve a possibly more biofidelic muscle behavior, which would even allow a functional dependency of the 1D and 3D muscle systems. However, the effect on calculation time and model stability of these models is yet unknown and should be considered in future studies for efficient AHBM applications.

scholarly journals Personalized Clothing Design Support System for Special Crowds Based on Artificial Intelligence Technology

2021 ◽  
Vol 2066 (1) ◽  
pp. 012015
Author(s):  
Yuli Hu
Keyword(s):  
Human Body ◽  
Three Dimensional ◽  
Costume Design ◽  
Scanning System ◽  
Human Body Model ◽  
Clothing Design ◽  
Function Modules ◽  
Artificial Intelligence Technology ◽  
Design Software ◽  
Human Body Models

Abstract In today’s society, people’s demand for personalized clothing is increasing, and they are increasingly pursuing traditional elements. Therefore, many fashion designers will incorporate folk elements into the traditional clothing design concepts to meet this demand. Sc a kind of computer technology Personalized auxiliary design software is produced. The function of this software is to use the MVC architecture to create system function modules, and then use the Kinect-based three-dimensional scanning system to model the human body, so as to clearly understand and obtain human body models with different characteristics. Take the folk art elements of opera as an example, integrate the opera elements into the costume design and save it in the database of the system. Under the action of the virtual algorithm, the personalized costume is matched with the human body model, which completes the costume design. Personalized design, and better design results can be obtained through this auxiliary design software.

scholarly journals Personalization of a Human Body Model Using Subject-Specific Dimensions for Designing Clothing Patterns

2021 ◽  
Vol 11 (21) ◽  
pp. 10138
Author(s):  
Luděk Hynčík ◽  
Hana Čechová ◽  
Tomasz Bońkowski ◽  
Gabriela Kavalířová ◽  
Petra Špottová ◽  
...  
Keyword(s):  
Human Body ◽  
Injury Risk ◽  
Population Group ◽  
Human Body Model ◽  
Chinese Adults ◽  
Biomechanical Models ◽  
Body Model ◽  
Subject Specific ◽  
Human Body Models ◽  
Safety Systems

Virtual human body models contribute to designing safe and user-friendly products through virtual prototyping. Anthropometric biomechanical models address different physiques using average dimensions. In designing, e.g., personal protective equipment, orthopedic tools, or vehicle safety systems, biomechanical models with the correct geometry and shape shall play a role. The presented study shows the variations of subject-specific anthropometric dimensions from the average of the different population groups in the Czech Republic and China as a background for the need for personalized human body models. The study measures a set of dimensions used to design clothing patterns of Czech children, Czech adolescents, Czech adults, and Chinese adults and compares them to the corresponding age average, which is represented by a scaled anthropometric human body model. The cumulative variation of the dimensions used to design the clothing patterns increases the further the population group is from the average. It is smallest for the Czech adults at 7.54 ± 6.63%; Czech adolescents report 7.93 ± 6.25%; Czech children differ be 9.52 ± 6.08%. Chinese adults report 10.86 ± 11.11%. The variations from the average of the particular dimensions used to design clothing patterns prove the necessity of having personalized subject-specific models. The measured dimensions used to design the clothing patterns serve as the personalization of particular body segments and lead to a subject-specific virtual model. The developed personalization algorithm results in the continuous body surface desired for contact applications for assessing body behavior and injury risk under impact loading.

scholarly journals Analysis of individual differences in pelvic and spine alignment in seated posture and impact on the seatbelt kinematics using human body model

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254120
Author(s):  
Norihiro Nishida ◽  
Tomohiro Izumiyama ◽  
Ryusuke Asahi ◽  
Fei Jiang ◽  
Junji Ohgi ◽  
...  
Keyword(s):  
Human Body ◽  
Cervical Vertebrae ◽  
Seat Belt ◽  
Compressive Load ◽  
Human Model ◽  
Human Body Model ◽  
Finite Element Software ◽  
Posterior Tilt ◽  
Human Body Models ◽  
The Impact

Analysis using human body models has been performed to reduce the impact of accidents; however, no analysis has shown a relationship between lumbar and pelvic/spine angle and seat belts in reducing human damage from accidents. Lumbar and pelvic/spine angles were measured in 75 individuals and the measurements were used to create three different angles for the Total Human Model for Safety model. In the present study, we focused on lumber lordosis (LL) and pelvic angle (PA). A normal distribution and histogram were used for analysis of PA (01, 10, and 50). The Total Human Model for Safety, including LL and PA, was corrected using finite element software. Simulations were conducted under the conditions of the Japan New Car Assessment Programme (JNCAP) 56 kph full lap frontal impact. Using the results of the FEM, the amount of lap-belt cranial sliding-up, anterior movement of the pelvis, posterior tilt of the pelvis, head injury criterion (HIC), second cervical vertebrae (C2) compressive load, C2 moment, chest deflectiou (upper, middle, and lower), left and right femur load, and shoulder belt force were measured. The lap-belt cranial sliding-up was 1.91 and 2.37 for PA10 and PA01, respectively, compared to PA50; the anterior movement of the pelvis was 1.08 and 1.12 for PA10 and PA01, respectively; and the posterior tilt of the pelvis was 1.1 and 1.18 for PA10 and PA01, respectively. HIC was 1.13 for PA10 and 1.58 for PA01; there was no difference in C2 compressive load by PA, but C2 moment increased to 1.59 for PA10 and 2.72 for PA01. It was found that as LL increases and the PA decreases, the seat belt becomes likely to catch the iliac bone, making it harder to cause injury. This study could help to reconsider the safe seat and seatbelt position in the future.

An Objective Evaluation of Mass Scaling Techniques Utilizing Computational Human Body Finite Element Models

2016 ◽  
Vol 138 (10) ◽  
Author(s):  
Matthew L. Davis ◽  
F. Scott Gayzik
Keyword(s):  
Human Body ◽  
Method Development ◽  
Human Subjects ◽  
Objective Evaluation ◽  
Similarity Score ◽  
Mass Scaling ◽  
Response Data ◽  
Human Body Models ◽  
Single Technique ◽  
Equal Density

Biofidelity response corridors developed from post-mortem human subjects are commonly used in the design and validation of anthropomorphic test devices and computational human body models (HBMs). Typically, corridors are derived from a diverse pool of biomechanical data and later normalized to a target body habitus. The objective of this study was to use morphed computational HBMs to compare the ability of various scaling techniques to scale response data from a reference to a target anthropometry. HBMs are ideally suited for this type of study since they uphold the assumptions of equal density and modulus that are implicit in scaling method development. In total, six scaling procedures were evaluated, four from the literature (equal-stress equal-velocity, ESEV, and three variations of impulse momentum) and two which are introduced in the paper (ESEV using a ratio of effective masses, ESEV-EffMass, and a kinetic energy approach). In total, 24 simulations were performed, representing both pendulum and full body impacts for three representative HBMs. These simulations were quantitatively compared using the International Organization for Standardization (ISO) ISO-TS18571 standard. Based on these results, ESEV-EffMass achieved the highest overall similarity score (indicating that it is most proficient at scaling a reference response to a target). Additionally, ESEV was found to perform poorly for two degree-of-freedom (DOF) systems. However, the results also indicated that no single technique was clearly the most appropriate for all scenarios.

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