Vertical Impulse Analysis of Seat Belt Buckles

2002 ◽  
Author(s):  
Richard Clarke ◽  
Anthony Sances
Keyword(s):  
Validation Studies ◽  
Seat Belt ◽  
Vertical Acceleration ◽  
Test Fixture ◽  
Vertical Accelerations ◽  
Standard Production ◽  
Acceleration Test

Review of various buckle testing studies is given. More than 100 different standard production end release seat belt buckles have been tested and repeatability and validation studies have been done. The buckle stalks were modified to accommodate the vertical acceleration test fixture. Some buckles opened with vertical accelerations as low as 91 g’s while others did not release at levels as high as 489 g’s.

Analysis of Side Release Motor Vehicle Seat Belt Buckles

2004 ◽  
Author(s):  
Richard Clarke ◽  
Anthony Sances ◽  
Srirangam Kumaresan ◽  
Steve Syson
Keyword(s):  
Motor Vehicle ◽  
Seat Belt ◽  
Test Sample ◽  
Constant Load ◽  
Vertical Acceleration ◽  
Test Fixture ◽  
Current Test ◽  
Low Pass ◽  
Vehicle Seat ◽  
Pneumatic Shock

The purpose of the current study was to evaluate the likelihood of inertial release of various production side release automotive seat belt buckles under acceleration loading conditions that could be expected to occur in real world accident events. Each test sample was secured to a specially designed vertical acceleration test fixture. This produced a rigid mount, which allowed impacts to be transmitted to the test buckle. A commercially available M/RAD 0909 Pneumatic Shock Machine was used to control the magnitude, shape and duration of the pulses transmitted to the fixture and test buckle. To measure and analyze the shock pulse generated by the M/RAD Pneumatic Shock Machine, an M/RAD SRA-1200 Shock Instrumentation System was used with the capacity to capture, display and analyze half-sine, saw tooth and square wave pulses. A display screen and computer printouts record peak accelerations, pulse durations and change in velocity. An ICP 305A04 accelerometer was attached to the base of the test fixture. All information was recorded at a rate of 8 kHz and was filtered using a digital four pole Butterworth zero phase shift filter, and a low pass filtering system set at L-P1 with a cutoff of 1100 Hz. The current test fixture was designed to accommodate various production side release buckles with interchangeable jaw plates, for the different style buckles, to provide a “rigid mount.” A constant load can be placed on the latch plate and can be varied from 4 to 133 N. The forces for a fixed latch side buckle did not open upto accelerations of about 480 G’s. In contrast, unprotected side release buckle released at accelerations of about one fourth that of protected.

scholarly journals Smartphone monitoring of in-ambulance vibration and noise

2021 ◽  
pp. 095441192098599
Author(s):  
Tom Partridge ◽  
Lorelei Gherman ◽  
David Morris ◽  
Roger Light ◽  
Andrew Leslie ◽  
...  
Keyword(s):  
Transport Systems ◽  
Vertical Acceleration ◽  
Vehicle Speed ◽  
Noise Levels ◽  
The Road ◽  
Neonatal Transport ◽  
Mass Data ◽  
Transport Team ◽  
Vertical Accelerations ◽  
Noise Vibration

Transferring sick premature infants between hospitals increases the risk of severe brain injury, potentially linked to the excessive exposure to noise, vibration and driving-related accelerations. One method of reducing these levels may be to travel along smoother and quieter roads at an optimal speed, however this requires mass data on the effect of roads on the environment within ambulances. An app for the Android operating system has been developed for the purpose of recording vibration, noise levels, location and speed data during ambulance journeys. Smartphone accelerometers were calibrated using sinusoidal excitation and the microphones using calibrated pink noise. Four smartphones were provided to the local neonatal transport team and mounted on their neonatal transport systems to collect data. Repeatability of app recordings was assessed by comparing 37 journeys, made during the study period, along an 8.5 km single carriageway. The smartphones were found to have an accelerometer accurate to 5% up to 55 Hz and microphone accurate to 0.8 dB up to 80 dB. Use of the app was readily adopted by the neonatal transport team, recording more than 97,000 km of journeys in 1 year. To enable comparison between journeys, the 8.5 km route was split into 10 m segments. Interquartile ranges for vehicle speed, vertical acceleration and maximum noise level were consistent across all segments (within 0.99 m . s−1, 0.13 m · s−2 and 1.4 dB, respectively). Vertical accelerations registered were representative of the road surface. Noise levels correlated with vehicle speed. Android smartphones are a viable method of accurate mass data collection for this application. We now propose to utilise this approach to reduce potential harmful exposure, from vibration and noise, by routing ambulances along the most comfortable roads.

scholarly journals RESULTS OF EXPERIMENTAL STUDIES OF ACCELERATIONS OF THE DM-617 VIBRATORY ROLLER USING DIGITAL SIGNAL PROCESSING TECHNOLOGY

2020 ◽  
Vol 17 (2) ◽  
pp. 182-195
Author(s):  
I. S. Tiuremnov ◽  
S. N. Ivanov ◽  
A. S. Kraiushkin
Keyword(s):  
Mathematical Models ◽  
Dynamic Modulus ◽  
Vibration Mode ◽  
Operation Mode ◽  
Experimental Studies ◽  
Vertical Vibration ◽  
Vertical Acceleration ◽  
Soil Deformation ◽  
Compacted Soil ◽  
Vertical Accelerations

Introduction. To improve the vibrating rollers in order to increase sealing capacity, reliability and vibration safety, the interaction of vibrating roller parts between each other and with compacted soil is simulated mathematically. The developed models are validated, i.e. compared with the results of experimental studies. However, the known results of experimental studies were obtained based on a relatively small list of vibrating roller models and soil types, as well as in a steady vibration mode. The paper presents the results of experimental studies, which used a vibratory drum of a roller to study its vertical vibration accelerations both in the steady vibration, as well as transient mode at turning the vibration generator on (speedup) and off (halt). This expands the range of opportunities to validate the existing and newly developed mathematical models.Materials and methods. Experimental studies of vertical vibration accelerations of a drum were conducted using the DM-617 vibrating roller when compacting natural sand-gravel aggregate. The accelerometer readings show high-frequency harmonics, which makes it significantly more difficult to determine amplitude values of vibration accelerations, therefore a low-frequency filter with a boundary frequency of 200 Hz was used for digital processing.Results. It was determined that when the DM-617 vibrating roller is compacting soil with maximum driving force within the range of variation of dynamic modulus of soil deformation Evd=14…25 MPа, amplitude values of vertical vibration accelerations of the vibratory drum are from 65... 77 to -61... -69 m/s2 . At the start-up (speedup) of vibration generator, acceleration amplitudes are 1.1 times higher than vertical accelerations of steady operation mode of the vibrating drum and practically do not depend on the dynamic modulus of soil deformation Evd. At turning off (stop) of the vibration generator, amplitude of vertical accelerations do not exceed the vertical accelerations of the steady operation mode of the vibratory drum.Discussion and conclusion. The vertical acceleration amplitudes of vibratory drums of DM-617 do not depend on the dynamic soil deformation modulus Evd, and this is consistent with the results of experimental studies of the vibratory drum mounted on DM-614. The obtained vertical vibration accelerations of the drum mounted on DM-617 in the steady vibration mode, as well as at switching the vibration generator on (speedup) and off (halt) make it possible to verify the existing and developed mathematical models of interaction of vibrating rollers with compacted soil.Financial transparency: the authors have no financial interest in the presented materials or methods. There is no conflict of interest.

Measurement and Prediction of the Pedestrian-Induced Vibrations of a Footbridge

2009 ◽  
Vol 40 (4) ◽  
pp. 10-19
Author(s):  
P. Van den Broeck ◽  
G. De Roeck ◽  
E. Reynders ◽  
D. Degrauwe ◽  
I. Bojidarova Georgieva ◽  
...  
Keyword(s):  
Prediction Method ◽  
Element Model ◽  
Vertical Acceleration ◽  
Load Model ◽  
Acceleration Level ◽  
Numerical Predictions ◽  
Vibration Serviceability ◽  
Increasing Trend ◽  
Series Of Experiments ◽  
Vertical Accelerations

Vibration serviceability has become an important issue in the design of modern slender footbridges with large spans. This paper presents the measurements and the numerical predictions of the footfall-induced vibrations of a pedestrian bridge. A series of experiments were carried out with different-sized groups crossing the bridge, varying in number from 10 up to 50 participants and recording the vertical and lateral accelerations at different locations on the bridge. Two types of tests were performed: free walking and synchronized walking by means of a metronome signal, recorded on a tape recorder carried by the group of students. The effect of the test type is analyzed and shows a magnitude in difference between the vertical accelerations caused by the free and the synchronized walking. The increasing trend of the acceleration levels with increasing group size is also clearly observed. A numerical prediction method is used to simulate the synchronized walking experiments based on an updated finite element model of the bridge and a single pedestrian load model. It is shown that the predicted acceleration level is sensitive to the assumptions made regarding the level of synchronization between the pedestrians and the magnitude of the dynamic load generated by each pedestrian. Taking into account these specific measurement conditions, a fair agreement is obtained between the predicted and the observed vertical acceleration levels at seven positions along the length of the footbridge.

scholarly journals Experimental and numerical assessment of vertical accelerations during bow re-entry of a RIB in irregular waves

2021 ◽  
pp. 1-26
Author(s):  
Martin van der Eijk ◽  
Peter Wellens
Keyword(s):  
Numerical Method ◽  
Structural Damage ◽  
Stokes Equations ◽  
State Of The Art ◽  
Irregular Waves ◽  
Vertical Acceleration ◽  
Damage State ◽  
Severe Injuries ◽  
Strip Theory ◽  
Vertical Accelerations

This paper presents the comparison of a self-conducted towing tank experiment with the simulation results of a calibrated state-of-the-art strip-theory method and a first-principles numerical method. The experiment concerns a Rigid Inflatable Boat (RIB) in moderate-to-high irregular waves. These waves result in bow emersion events of the RIB. Bow re-entry induces vertical accelerations which, in reality, can lead to severe injuries and structural damage. State-of-the-art methods for predicting the vertical acceleration levels are based on assumptions, require calibration and are often limited in application range. We demonstrate how the vertical acceleration as a function of time is found from a 3D numerical method based on the Navier–Stokes equations, employing the Volume of Fluid (VoF) method for the free surface, without any further assumptions or limitations. 2D+t strip theory methods like Fastship are based on the mechanics of wedges falling in water. The 3D numerical method that is part of the software ComFLOW is compared to previous research on falling wedges in 2D to investigate the effect of air and to find suitable grid distances for the 3D simulation of the RIB. The 3D RIB simulations are compared to Fastship and the experiment. With respect to the experiment, the ComFLOW simulations show a slight underestimation of the levels of heave and pitch. The underestimation of Fastship is larger. The prediction of acceleration in ComFLOW is hardly different from the experiment and a significant improvement with respect to Fastship. ComFLOW is demonstrated to predict acceleration levels better than before, which creates opportunities for using it in seakeeping optimization and for the improvement of methods like Fastship. The properties of the RIB and the experiment are available as open data at Wellens (2020).

Operating an industry-grade quantum differential gravimeter

2020 ◽  
Author(s):  
Camille Janvier ◽  
Vincent Ménoret ◽  
Jean Lautier ◽  
Bruno Desruelle ◽  
Sebastien Merlet ◽  
...  
Keyword(s):  
Accurate Determination ◽  
Vertical Gradient ◽  
Physical Principle ◽  
Gravity Gradient ◽  
Vertical Acceleration ◽  
Short Term ◽  
Gravity Measurements ◽  
Vertical Accelerations ◽  
The Stability ◽  
Absolute Quantum

<p>After three years of development in collaboration with LNE-SYRTE, we report on the development, the integration and the preliminary operation of an industry-grade absolute differential gravimeter. This new generation of instrument goes beyond the possibilities offered by existing gravity gradiometers, as one differential gravimeter measures simultaneously g and the vertical gradient of g [1]. Relying on atom interferometry with cold 87 Rb atoms, a single vertical laser beam simultaneously measures the vertical acceleration experienced by two sets of laser-cooled atoms free-falling from different heights. For each drop, the half-sum of the two vertical accelerations gives access to g and the half-difference to dg / dz. As far as technology is concerned, our differential gravimeter relies on a physical principle and a set of technologies that have already been validated for absolute quantum gravimeters [2].</p><p><br>Our demonstrator is operational since November 2019 and has shown the ability to run continuously for more 18 days without any human attendance.  We will present in detail the experimental results for the measurement of g and dg / dz. Regarding the measurement of the vertical gradient of g, we obtain a short-term sensitivity of 76 E/√t (1E = 10 -9 s -2 = 0.1 µGal/m) and a resolution of a 4 E when data is averaged over 1000 s. Regarding the measurement of g itself, we obtain a short-term sensitivity of 36 µGal/√t and a resolution of a few µGal when data is averaged over 500 s. These are preliminary results and options and future plan to improve the sensitivity and the stability of the measurements will be discussed.</p><p><br>Such quantum differential gravimeter is to our knowledge the only technology that allows for an absolute continuous drift-free monitoring of simultaneously gravity and gravity gradient over timescales from a few minutes to several months.</p><p> </p><p>This work has been supported by the DGA, the French Department of Defense.</p><p> </p><p>[1] R. Caldani <em>et al.</em>, "Simultaneous accurate determination of both gravity and its vertical gradient", Phys. Rev. A <strong>99</strong>, 033601 (2019)</p><p>[2] V. Ménoret <em>et al.</em>, "Gravity measurements below 10−9 g with a transportable absolute quantum gravimeter", Nature Scientific Reports, vol. 8, 12300 (2018)</p>

scholarly journals The Influence of the Driving Speed and Vertical Acceleration of the Mobile Machine on the Change of Soil Packing

2018 ◽  
Vol 7 (4.3) ◽  
pp. 179 ◽  
Author(s):  
Mykola Artiomov ◽  
Dmytro Klets ◽  
Volodymyr Boldovskyi ◽  
Andrii Makovetsky ◽  
Kateryna Kostyk
Keyword(s):  
Soil Compaction ◽  
Density Variation ◽  
Gear System ◽  
Dynamic Loads ◽  
Vertical Acceleration ◽  
Soil Density ◽  
Driving Speed ◽  
Vertical Accelerations ◽  
Traction Load ◽  
Mobile Machine

The article deals with the processes of changing the vertical forces acting on the propulsion of mobile machines, causing soil compaction when changing the driving speed and vertical accelerations of a mobile machine moving on a deformable soil. The influence of parameters and characteristics of the running gear system of the wheeled tractor, as well as the traction load on the value of vertical accelerations when moving along the soil, is determined. The dependence of the influence of vertical accelerations on the dynamic loads on the axle of the tractor front and rear axles is determined. The dependence of the soil density variation caused by the action of dynamic loads from the propulsion of the tractor front and rear axles has been determined.  

Gunner Performance in a Motion Environment: A Comparison of Controls

1997 ◽  
Vol 41 (2) ◽  
pp. 1056-1060
Author(s):  
Monica M. Glumm ◽  
Jock O. Grynovicki ◽  
John D. Waugh
Keyword(s):  
Target Motion ◽  
Vertical Acceleration ◽  
Motion Simulator ◽  
Induced Motion ◽  
Vertical Accelerations ◽  
Four Levels ◽  
Aberdeen Proving Ground

This paper describes a study designed to quantify the effects of vehicular induced motion on tank gunner performance using two different control handles. One control was a fixed yoke that incorporated a thumb-operated, tracking button. The second control was a more conventional displacement yoke which functioned like that in the current M1A1 tank. The study was conducted on a ride motion simulator which had been programmed to impart four levels of ride motion. These ride levels were simulations of the Ml tank traveling over various test courses at Aberdeen Proving Ground, MD. Generally, as vertical acceleration increased, performance decreased for both controls; however, the vertical accelerations imparted to the gunners at the more severe ride levels effected a greater reduction in time on target when gunners used the thumb button than the accelerations did when gunners used the displacement yoke. Performance using the thumb button was also more affected by target motion.

A Comparison of Methods for Determining Significant Wave Heights—Applied to a 3-m Discus Buoy during Hurricane Katrina

2010 ◽  
Vol 27 (6) ◽  
pp. 1012-1028 ◽  
Author(s):  
L. C. Bender ◽  
N. L. Guinasso ◽  
J. N. Walpert ◽  
S. D. Howden
Keyword(s):  
Hurricane Katrina ◽  
Degrees Of Freedom ◽  
Accurate Estimate ◽  
Vertical Acceleration ◽  
Orientation Data ◽  
Mississippi Sound ◽  
Wave Heights ◽  
Vertical Accelerations ◽  
6 Degrees Of Freedom ◽  
Gps Antenna

Abstract In August 2005, the eye of Hurricane Katrina passed 90 km to the west of a 3-m discus buoy deployed in the Mississippi Sound and operated by the Central Gulf of Mexico Ocean Observing System (CenGOOS). The buoy motions were measured with a strapped-down, 6 degrees of freedom accelerometer, a three-axis magnetometer, and from the displacement of a GPS antenna measured by postprocessed-kinematic GPS. Recognizing that an accelerometer experiences a large offset due to gravity, the authors investigated four different means of computing wave heights. In the most widely used method for a buoy with a strapped-down, 1D accelerometer, wave heights are overestimated by 26% on average and up to 56% during the peak of the hurricane. In the second method, the component of gravity is removed from the deck relative z-axis accelerations, requiring pitch and roll information. This is most similar to the motion of the GPS antenna and reduces the overestimation to only 5% on average. In the third method, the orientation data are used to obtain a very accurate estimate of the vertical acceleration, reducing the overestimation of wave heights to 1%. The fourth method computes an estimate of the true earth-referenced vertical accelerations using the accelerations from all three axes but not the pitch and roll information. It underestimates the wave heights by 2.5%. The fifth method uses the acceleration from all three axes and the pitch and roll information to obtain the earth-referenced vertical acceleration of the buoy, the most accurate measure of the true wave vertical acceleration. The primary conclusion of this work is that the measured deck relative accelerations from a strapped-down, 1D accelerometer must be tilt corrected in environments of high wave heights.

scholarly journals Using In-Vehicle Monitoring Data to Assess Road Conditions of Traffic Flows

2022 ◽  
Vol 19 (4) ◽  
pp. 34-39
Author(s):  
I. O. Chernyaev ◽  
S. A. Evtyukov
Keyword(s):  
Adaptive Systems ◽  
The Body ◽  
Road Surface ◽  
Vehicle Body ◽  
Average Level ◽  
Time Interval ◽  
Vertical Acceleration ◽  
Traffic Flows ◽  
The Road ◽  
Vertical Accelerations

 Developments in adaptive systems for maintenance and repair of automotive vehicles set the task of monitoring the conditions of their operation. One of the main factors determining these conditions is the type of road surface.The article describes the results of identification of the type (and condition) of the road surface obtained by theoretical and experimental methods based on the analysis of vertical accelerations recorded on the vehicle body.The purpose of research was to provide a possibility of continuous monitoring of the type of road surface on which a vehicle is driving, with the subsequent application of the obtained data to correct maintenance intervals. The results of experiments have shown the dependence of the vertical acceleration of the body on the micro-profile of the road surface. The described experimentally obtained profiles of vertical accelerations refer to different types of road surface in different conditions. For quantitative assessment, it is proposed to calculate the average level of accelerations as an integral average over a certain time interval.The results of the experiments have allowed to substantiate the empirical dependence of the average level of accelerations on speed of a vehicle. Based on this dependence, a method is proposed for recalculating the current values of the average levels of accelerations obtained at different speeds into values adjusted to the base speed to ensure the possibility of their comparison.It is shown that based on the values of average acceleration levels obtained through operation monitoring regarding a previously known type of road surface, it is possible to determine its condition. A short algorithm is formulated for practical implementation and assessment of road conditions of traffic flows. As for hardware, it is proposed not to equip a vehicle with additional sensors but to use operational standard accelerometers as part of in-vehicle emergency call systems, e.g., ERA-GLONASS equipment units. 

Sign in / Sign up

Export Citation Format

Share Document