A Method for the Assessment of the Dynamic Performance of Neck Protection Devices

2013 ◽  
Author(s):  
Gianmarco Galmarini ◽  
Massimiliano Gobbi ◽  
Gianpiero Mastinu ◽  
Giorgio Previati
Keyword(s):  
Impact Load ◽  
Dynamic Performance ◽  
Head Injuries ◽  
Test Procedure ◽  
Neck Injury ◽  
Multibody Model ◽  
Hybrid Iii ◽  
Protection Devices ◽  
Male Hybrid ◽  
The Impact

In this paper a method for the evaluation of the dynamic performance of neck protection devices for motorcyclists is presented. The research project involves both experimental and numerical activities. An impulsive load is applied to the head of a 50th percentile male Hybrid III dummy while wearing a helmet by means of a pendulum of calibrated mass starting from a well-defined initial condition. The impact load and the load at the neck of the dummy are measured by means of two six axes load cells. Additionally, head linear and rotational accelerations are measured. The test procedure shows a very good repeatability and allows for the comparison of the force passing through the neck with and without neck protection devices. Since neck protection devices should work in situations in which no relevant head injuries are present, the experimental parameters (pendulum mass and speed) are chosen to cause a high probability of injuries to the neck together with a low probability of damages to the head while wearing a standard helmet. Injury indices, found in the literature, have been used to determine the neck injury level. A multibody model of the human neck, developed in Matlab™ SimMechanics™, is validated by using the data acquired during the tests. A study of real-world crashes has allowed the identification of reference impact scenarios which have been simulated by using the multibody model. The validated model is suitable to determine the chance that a motorcyclist would have significant neck injury with or without a neck protecting device.

ON TESTING THE SHOCK-ABSORBING SEATS FOR HELICOPTER CREW MEMBERS

2021 ◽  
Vol 55 (3) ◽  
pp. 62-65
Author(s):  
Yu.B. Moiseev ◽  
Keyword(s):  
Dynamic Performance ◽  
Impact Testing ◽  
The Other ◽  
Test Device ◽  
Anthropometric Data ◽  
Test Platform ◽  
Helicopter Pilots ◽  
Hybrid Iii ◽  
Male Hybrid ◽  
The Impact

Recommendations on improving the dynamic performance of shock-absorbing seats for helicopter pilots resulted from analysis of the Russian pilots' anthropometric data and helicopter 3-d attitude and position during emergency landing. The idea is to complement the existing list of impact tests with two more tests in which the impact vector will be perpendicular to the test-platform horizontal. One of these tests should be performed with a light anthropomorphic test device (Hybrid-III) representing a 5-percentile female and the other, heavy Hybrid-III representing a 95-percentile male. For horizontal impact testing, the 50-percentile male Hybrid-III should be replaced by the 95-percentile Hybrid-III.

Dynamic Performance of Neck Protection Devices: Performance Analysis Based on a Simplified Multibody Model of the Human Neck

2012 ◽  
Author(s):  
Massimiliano Gobbi ◽  
Gianpiero Mastinu ◽  
Giorgio Previati ◽  
Ermes Tarallo
Keyword(s):  
Soft Tissues ◽  
Mechanical Response ◽  
Dynamic Performance ◽  
Safety Devices ◽  
Anatomy And Physiology ◽  
Multibody Model ◽  
Impulsive Loads ◽  
Protection Devices ◽  
Safety Systems ◽  
Deformation System

This work is focused on the evaluation of the dynamic performance of different neck protection devices. In order to evaluate the mechanical response of the safety devices, a multibody model of the human neck has been developed in Matlab™ SimMechanics™. The mechanical behavior of the neck is described in the paper and different injury indices are presented and compared. The information about anatomy and physiology of the cervical spine of the neck has been collected from the literature, with particular focus on the mechanism of damage of vertebrae, disks and soft tissues. The multibody model has been validated against experimental data available in the literature concerning impulsive loads representative of crash phenomena. By means of the presented model, some relevant injury indices are computed for an accident involving a motorcyclist. Since the focus has been set on mild injuries of the neck, the simulated crash should cause a high probability of injuries of the neck together with a low probability of damages of the head while wearing a standard helmet. The performance of neck safety devices that link the helmet with the thoracic-shield are evaluated and compared. For sake of clearness, three types of neck safety devices are considered referencing to US patents: an airbag jacket, a 3D cushion wrapping the motorcyclist’s neck, and a “spring and dampers” system. The airbag jacket has been modeled as a high stiffness and low deformation system by considering the airbag in its fully deployed configuration and by neglecting its dynamic performance during inflation phase. The other safety devices have been modeled as lumped parameters spring-damper systems. A sensitivity analysis on the injury indexes has been performed by changing the stiffness and the damping parameters of these safety systems. The injury indexes collected by simulating the different neck safety systems have been compared.

Modeling and Analysis of Single Hydraulic Props in Coal Mines

2016 ◽  
Vol 693 ◽  
pp. 364-372
Author(s):  
Tao He ◽  
Cao Feng Yu ◽  
Xiao Lei Wu ◽  
Hai Shun Deng
Keyword(s):  
Support System ◽  
Safety Valve ◽  
Impact Load ◽  
Dynamic Performance ◽  
Core Stability ◽  
Mine Safety ◽  
Dead Volume ◽  
Modeling And Analysis ◽  
Hydraulic Prop ◽  
The Impact

This research is focused on dynamic performance of water hydraulic single hydraulic prop, the mathematical and AMESim model of single hydraulic prop are established. And the drop hammer is introduced to simulate the impact load of the surrounding rock acting on the prop. The performance parameters of prop retract displacement and cavity pressure are used as the research objects. The working process of single hydraulic prop is reproduced by the simulation. And the influence of safety valve parameters on the support system is analyzed. The results show that: increasing maximal valve core stroke and dead volume or reducing valve damping hole diameter can improve the support performance of the single hydraulic prop. But the influence of equivalent damping has two sides. For support system, decrease damping can improve the support performance, but for the safety valve, reduce the damping make the valve core stability decline. In addition, the pressure overshoot of the optimized system is 18.3%, adjusting time is 0.5s and the retract displacement is 10mm. The dynamic performances meet the technology requirements of the coal mine safety production of China.

Analysis of Stand-Up Forklift Operator Injuries in Off-the-Dock and Tip-Over Incidents With a Latched Door on the Operator Access Opening

2016 ◽  
Vol 2 (2) ◽  
Author(s):  
John F. Wiechel ◽  
William R. “Mike” Scott
Keyword(s):  
Head Injury ◽  
High Risk ◽  
High Speed ◽  
Neck Injury ◽  
Thoracic Injury ◽  
Shoulder Injury ◽  
Test Device ◽  
Impact Tests ◽  
Hybrid Iii ◽  
The Impact

A series of tip-over and off-the-dock impact tests were performed with stand-up forklifts to investigate the potential for injury to the operator of a forklift in these types of accidents, when the forklift is equipped with an operator’s compartment door. One Crown Equipment Company 35RRTT Model and one 35RCTT Model stand-up forklifts were used in the impact tests. The only modification to the forklifts for the tests was the placement of a door on the entrance to the operator’s compartment. A Hybrid III anthropomorphic test device (ATD) was placed in the operator’s compartment as a human surrogate. During each test, head accelerations, chest accelerations, neck loads, and lumbar loads were measured on the ATD. The motion of the forklift and the ATD were filmed with real-time video and high-speed cameras. Results from the impact tests indicate that there is a high risk of head injury in a right-side tip-over accident and a high risk of head injury and neck injury in a left-side tip-over accident. There is a high risk of a head injury, neck injury, and thoracic injury in off-the-dock forks-trailing accidents. In an off-the-dock forks-leading accident, there is a high risk of arm/shoulder injury, head injury, and neck injury. In both tip-over and off-the-dock forks-trailing accidents, there is a high probability of an entrapment injury under the overhead guard on the forklift.

The Effect of an Operator Compartment Door on Standup Forklift Off-Dock and Tip-Over Injuries

2013 ◽  
Author(s):  
John F. Wiechel ◽  
William R. (Mike) Scott
Keyword(s):  
Head Injury ◽  
High Risk ◽  
High Speed ◽  
Neck Injury ◽  
Thoracic Injury ◽  
Shoulder Injury ◽  
Test Device ◽  
Impact Tests ◽  
Hybrid Iii ◽  
The Impact

A series of tip-over and off-the-dock impact tests were performed with stand-up forklifts in order to investigate the potential for injury to the operator of a forklift in these types of accidents when the forklift is equipped with an operator’s compartment door. One Crown Equipment Company RR Model and one RC Model stand-up forklift were used in the impact tests. The only modification to the forklifts for the tests was the placement of a door on the entrance to the operator’s compartment. A Hybrid III anthropomorphic test device (ATD) was placed in the operator’s compartment as a human surrogate. During each test, head accelerations, chest accelerations, neck loads and lumbar loads were measured on the ATD. The motion of the forklift and the ATD were filmed with video and high-speed cameras. Results from the impact tests indicate that there is a high risk of head injury in a right side tip-over accident and a high risk of head injury and neck injury in a left side tip-over accident. There is a high risk of a head injury, neck injury and thoracic injury in off-the-dock forks-trailing accidents. In an off-the-dock forks-leading accident there is a high risk of arm/shoulder injury, head injury, and neck injury. In both tip-over and off-the-dock forks-trailing accidents there is a high probability of an entrapment injury under the overhead guard on the forklift.

scholarly journals Experimental Study on the Impact Load of Hybrid III 50th Male Dummy in Elevator Car

2021 ◽  
Vol 2044 (1) ◽  
pp. 012181
Author(s):  
Xiaochang Liu ◽  
Facai Ren ◽  
Xiao Liang ◽  
Bo Wang
Keyword(s):  
Experimental Study ◽  
Impact Load ◽  
Hybrid Iii ◽  
The Impact

Response Corridors for Blunt Impacts to the Back

2021 ◽  
Vol 9 (1) ◽  
pp. 123-138
Author(s):  
Chantal S Parenteau ◽  
David C Viano ◽  
Warren N Hardy
Keyword(s):  
Motor Vehicle ◽  
Human Subjects ◽  
Neck Extension ◽  
Safety Standards ◽  
Crash Testing ◽  
Blunt Impact ◽  
Hybrid Iii ◽  
Male Hybrid ◽  
The Impact ◽  
Head Neck

Corridors for the biofidelity of blunt impact to the back are important for sled and crash testing with Anthropomorphic Test Devices (ATDs). The Hybrid III is used in rear sled tests as part of Federal Motor Vehicle Safety Standards (FMVSS) 202a. The only corridor for biofidelity is the neck extension. Eight Post Mortem Human Subjects (PMHS) were subjected to 20 blunt impacts with a 15.2 cm (6 in.) diameter pendulum weighing 23.4 kg. The impact was below T1 at 4.5 m/s and 6.7 m/s and below T6 at 4.5 m/s centered on the back. Head, neck, and chest responses were reported in 2001 [8]. In this study, the responses were scaled to the 50th male Hybrid III, and corridors were determined defining biofidelity for blunt impacts to the back. The scaled data gives an average peak force of 3.44 kN ± 0.74 kN at T1 and 4.5 m/s, 5.08 kN ± 1.35 kN at T1 and 6.7 ms, and 3.4 kN ± 1.2 kN at T6 and 4.5 m/s. The corresponding scaled deflection was 44.0 ± 19.7 mm, 60.2 ± 21.2 mm, and 53.1 ± 16.5 mm. The average stiffness of the back was 1.21 kN/cm at T1 and 4.5 m/s, 1.17 kN/cm at T1 and 6.7 m/s, and 1.14 kN/cm at T6 and 4.5 m/s. The corridors help to define biofidelity and can be used to assess the performance of the Hybrid III, Biofidelic Rear Impact Dummy (BioRID) II, and other ATDs.

Noise Exposure and Hearing Disorders

2017 ◽  
Author(s):  
David C. Byrne ◽  
Thais C. Morata
Keyword(s):  
Hearing Loss ◽  
Noise Exposure ◽  
Hearing Protection ◽  
Noise Induced Hearing Loss ◽  
Hearing Disorders ◽  
Industrial Noise ◽  
Significant Impairment ◽  
Protection Devices ◽  
The Impact ◽  
Occupational Hearing Loss

Exposure to industrial noise and the resulting effect of occupational hearing loss is a common problem in nearly all industries. This chapter describes industrial noise exposure, its assessment, and hearing disorders that result from overexposure to noise. Beginning with the properties of sound, noise-induced hearing loss and other effects of noise exposure are discussed. The impact of hearing disorders and the influence of other factors on hearing loss are described. Typically, noise-induced hearing loss develops slowly, and usually goes unnoticed until a significant impairment has occurred. Fortunately, occupational hearing loss is nearly always preventable. Therefore, this chapter gives particular attention to recommendations for measures to prevent occupational hearing loss such as engineering noise controls and hearing protection devices.

Impact Load Buffering Method Based on Stress Wave Attenuation Principle

2019 ◽  
Vol 11 (02) ◽  
pp. 1950019 ◽  
Author(s):  
Lin Gan ◽  
He Zhang ◽  
Cheng Zhou ◽  
Lin Liu
Keyword(s):  
Stress Wave ◽  
Wave Attenuation ◽  
Impact Load ◽  
Dynamics Simulation ◽  
Scanning System ◽  
Isolation Method ◽  
Element Analysis ◽  
System A ◽  
High Emission ◽  
The Impact

Rotating scanning motor is the important component of synchronous scanning laser fuze. High emission overload environment in the conventional ammunition has a serious impact on the reliability of the motor. Based on the theory that the buffer pad can attenuate the impact stress wave, a new motor buffering Isolation Method is proposed. The dynamical model of the new buffering isolation structure is established by ANSYS infinite element analysis software to do the nonlinear impact dynamics simulation of rotating scanning motor. The effectiveness of Buffering Isolation using different materials is comparatively analyzed. Finally, the Macht hammer impact experiment is done, the results show that in the experience of the 70,000[Formula: see text]g impact acceleration, the new buffering Isolation method can reduce the impact load about 15 times, which can effectively alleviate the plastic deformation of rotational scanning motor and improve the reliability of synchronization scanning system. A new method and theoretical basis of anti-high overload research for Laser Fuze is presented.

scholarly journals A Rational Numerical Method for Simulation of Drop-Impact Dynamics of Oleo-Pneumatic Landing Gear

2021 ◽  
Vol 11 (9) ◽  
pp. 4136
Author(s):  
Rosario Pecora
Keyword(s):  
Numerical Method ◽  
Initial Conditions ◽  
Impact Load ◽  
Numerical Models ◽  
Landing Gear ◽  
Design Stage ◽  
Impact Dynamics ◽  
State Variables ◽  
Adopted Model ◽  
The Impact

Oleo-pneumatic landing gear is a complex mechanical system conceived to efficiently absorb and dissipate an aircraft’s kinetic energy at touchdown, thus reducing the impact load and acceleration transmitted to the airframe. Due to its significant influence on ground loads, this system is generally designed in parallel with the main structural components of the aircraft, such as the fuselage and wings. Robust numerical models for simulating landing gear impact dynamics are essential from the preliminary design stage in order to properly assess aircraft configuration and structural arrangements. Finite element (FE) analysis is a viable solution for supporting the design. However, regarding the oleo-pneumatic struts, FE-based simulation may become unpractical, since detailed models are required to obtain reliable results. Moreover, FE models could not be very versatile for accommodating the many design updates that usually occur at the beginning of the landing gear project or during the layout optimization process. In this work, a numerical method for simulating oleo-pneumatic landing gear drop dynamics is presented. To effectively support both the preliminary and advanced design of landing gear units, the proposed simulation approach rationally balances the level of sophistication of the adopted model with the need for accurate results. Although based on a formulation assuming only four state variables for the description of landing gear dynamics, the approach successfully accounts for all the relevant forces that arise during the drop and their influence on landing gear motion. A set of intercommunicating routines was implemented in MATLAB® environment to integrate the dynamic impact equations, starting from user-defined initial conditions and general parameters related to the geometric and structural configuration of the landing gear. The tool was then used to simulate a drop test of a reference landing gear, and the obtained results were successfully validated against available experimental data.

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