The Load Sharing Contribution of Spinal Facet Joint During Impact Loading: A Porcine Biomechanical Model

The components that share the loading of motion segment include the facet joint and disc. Nachemson [1] reported the facet joint share 18% of vertical loading in a motion segment; while many other researchers reported the load sharing percentage of facet joint ranges from 1% to 57% [2,3]. The current study developed a unique apparatus using an in vitro porcine spine model to quantify the alteration of loading in the facet joint under impact compressive loading at different loading conditions. A drop tower type impact apparatus was used to produce the impact energy for the motion segment. A 6-D load cell was placed under the specimen to detect the force and moment responses. The pressure sensor was inserted into the facet joint to find the contact force. The pointed axial compresive forces were applied at 8 locations from anterior to posterior of upper vertebrae to mimic different impact loading conditions. The impact energy was fixed at 1.2 J. We found that; when the loading was applied anteriorly, the facet joint sustained very small percentages of the loading; while the location of the loading moved posteriorly, the facet joint sharing percentages increased. The largest sharing percentages of facet joint reached 30% in the current study.

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Crushing Susceptibility of Vetch Seeds Under Impact Loading

Cercetari Agronomice in Moldova ◽

10.1515/cerce-2017-0031 ◽

2017 ◽

Vol 50 (4) ◽

pp. 5-16

Author(s):

F. Shahbazi

Keyword(s):

Moisture Content ◽

Impact Energy ◽

Impact Loading ◽

Impact Damage ◽

Mechanical Damage ◽

Seed Moisture Content ◽

Mean Values ◽

Seed Moisture ◽

Mathematical Relationships ◽

The Impact

AbstractMechanical damage of seeds due to harvest, handling and other process is an important factor that affects the quality and quaintly of seeds. The objective of this research was to determine the effects of moisture content and the impact energy on the breakage susceptibility of vetch seeds. The experiments were conducted at moisture contents of 7.57 to 25% (wet basis) and at the impact energies of 0.1, 0.2 and 0.3 J, using an impact damage assessment device. The results showed that impact energy, moisture content, and the interaction effects of these two variables significantly influenced the percentage breakage in vetch seeds (p<0.01). Increasing the impact energy from 0.1 to 0.3 J caused a significant increase in the mean values of seeds breakage from 41.69 to 78.67%. It was found that the relation between vetch seeds moisture content and seeds breakage was non-linear, and the extent of damaged seeds decreased significantlyas a polynomial (from 92.47 to 33.56%) with increasing moisture (from 7.57 to 17.5%) and reached a minimum at moisture level of about 17.5%. Further increase in seed moisture, however, caused an increase in the amount of seeds breakage. Mathematical relationships composed of seed moisture content and impact energy, were developed for accurately description the percentage breakage of vetch seeds under impact loading. It was found that the models have provided satisfactory results over the whole set of values for the dependent variable.

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Dynamic Energy Absorption Performances of Rain Forest Vehicle (RFV) under Frontal Impact

Jurnal Teknologi ◽

10.11113/jt.v67.2775 ◽

2014 ◽

Vol 67 (3) ◽

Author(s):

M. S. Othman ◽

Z. Ahmad

Keyword(s):

Energy Absorption ◽

Impact Energy ◽

Impact Loading ◽

Rain Forest ◽

Experimental Testing ◽

Rigid Wall ◽

Crash Analysis ◽

Frontal Impact ◽

Frontal Section ◽

The Impact

This paper treats the crash analysis and energy absorption response of Rain Forest Vehicle (RFV) subjected to frontal impact scenario namely impacting rigid wall and column. Dynamic computer simulation techniques validated by experimental testing are used to carry out a crash analysis of such vehicle. The study aims at quantifying the energy absorption capability of frontal section of RFV under impact loading, for variations in the load transfer paths and geometry of the crashworthy components. It is evident that the proposed design of the RFV frontal section are desirable as primary impact energy mitigation due to its ability to withstand and absorb impact loads effectively. Furthermore, it is found that the impact energy transmitted to the survival room may feasibly be minimized in these two impact events. The primary outcome of this study is design recommendation for enhancing the level of safety of the off-road vehicle where impact loading is expected.

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Dynamic Energy Absorption Performances of Rain Forest Vehicle (RFV) under Frontal Impact

Jurnal Teknologi ◽

10.11113/jt.v69.3153 ◽

2014 ◽

Vol 69 (3) ◽

Author(s):

M. S. Othman ◽

Z. Ahmad

Keyword(s):

Energy Absorption ◽

Impact Energy ◽

Impact Loading ◽

Rain Forest ◽

Experimental Testing ◽

Rigid Wall ◽

Crash Analysis ◽

Frontal Impact ◽

Frontal Section ◽

The Impact

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Experimental Study on the Energy-Release Characteristics of Fine-Grained Fe/Al Energetic Jets under Impact Loading

Materials ◽

10.3390/ma12203317 ◽

2019 ◽

Vol 12 (20) ◽

pp. 3317

Author(s):

Li ◽

Keyword(s):

Experimental Data ◽

Energy Release ◽

Impact Energy ◽

Impact Loading ◽

Energetic Materials ◽

Chemical Properties ◽

Microscopic Analysis ◽

Specific Content ◽

Fine Grained ◽

The Impact

The energy released by the active metal phase in fine-grained Fe/Al energetic materials enables the replacement of conventional materials in new types of weapons. This paper describes an experiment designed to study the energy-release characteristics of fine-grained Fe/Al energetic jets under impact loading. By means of dynamic mechanical properties analysis, the physical and chemical properties of Fe/Al energetic materials with specific content are studied, and the preparation process is determined. The energy-release properties of fine-grained Fe/Al jets subject to different impact conditions are studied based on experimental data, and energy-release differences are discussed. The results show that for fine-grained Fe/Al energetic materials to remain active and exhibit high strength, the highest sintering temperature is 550 °C. With increasing impact energy, the energy release of fine-grained Fe/Al energetic jets increases. At an impact-energy threshold of 121.1 J/mm2, the chemical reaction of the fine-grained Fe/Al energetic jets is saturated. The experimental data and microscopic analysis show that when the impact energy reaches the threshold, the energy efficiency ratio of Fe/Al energetic jets can reach 95.3%.

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Impact Energy for the First Crack of Reinforced Concrete with Partial Replacements of Sand by Fine Crumb Rubber

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.701.286 ◽

2013 ◽

Vol 701 ◽

pp. 286-290 ◽

Cited By ~ 1

Author(s):

Mustafa Maher Al-Tayeb ◽

B.H. Abu Bakar ◽

Hanafi Ismail ◽

Hazizan Md Akil

Keyword(s):

Reinforced Concrete ◽

Impact Energy ◽

Impact Loading ◽

Crumb Rubber ◽

Low Velocity Impact ◽

Moist Air ◽

Low Velocity ◽

Velocity Impact ◽

The Impact

Effects of partial replacements of sand by waste fine crumb rubber on the performance of reinforced concrete under low velocity impact loading were investigated. Specimens were prepared for 5%, 10% and 20 % replacements by volume of sand. All specimens were cured in moist air for 90 days. For each case, six beams of 100 mm ×100 mm × 500mm were subjected to 5.15 kg hammer from 900mm height. The number of blows of the hammer required to induce the first visible crack of the beam were recorded. The results are presented in terms of impact energy required for the first crack. The fine crumb rubbers increased the impact energy for first crack.

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Shock Attenuation of Intervertebral Disc Following Fatigue Loading

Journal of Mechanics ◽

10.1017/jmech.2011.2 ◽

2011 ◽

Vol 27 (1) ◽

pp. 9-17 ◽

Cited By ~ 1

Author(s):

C.-K. Chiang ◽

C.-L. Yang ◽

W.-C. Chen ◽

C.-H. Chang ◽

S.-C. Huang ◽

...

Keyword(s):

Impact Energy ◽

Fatigue Loading ◽

Phase Delay ◽

Contact Period ◽

Shock Attenuation ◽

Spinal Motion ◽

Risk Of Injury ◽

Motion Segment ◽

Force Transmissibility ◽

The Impact

ABSTRACTShock absorption is one of the fundamental biomechanical functions of disc. The knowledge of the effect of fatigue loading, impact energy and contact period on the disc shock attenuation is important in clarifying the risk factors of back pain and evaluating the efficacy of novel disc prosthesis. The purpose of this study is to find the changes of shock attenuation of motion segment after fatigue loading, and the effect of impact energy and contact period on the disc shock attenuation pre and post fatigue loading.The 3-unit porcine spinal motion segment was used for testing. The impact test was applied pre and post fatigue loading. Impact energy and contact period were controlled in the experiment. Shock attenuation properties, including the acceleration attenuation (AA) of disc, force transmissibility (FT) and phase delay of force (PDF) of motion segment, were calculated from the acceleration and force responses.The results showed that the shock attenuation properties (acceleration attenuation and force transmissibility) decreased post fatigue. The disc acceleration attenuation was independent of impact energy and contact period. The disc acceleration attenuation was 0.78 (−1.06dB) pre fatigue and 1.04 (0.14dB) post fatigue. The force transmissibility of motion segment decreased post fatigue only during short contact period. The phase delay of force did not change significantly post fatigue.We found that the fatigue loading decreased the disc shock attenuation. The disc was at higher risk of injury following fatigue loading even at a mild impact loading. The disc acceleration attenuation was invariant of impact energy and contact period, but decreased post fatigue. The disc acceleration attenuation is a good index to evaluate the degree of fatigue injury.

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Single impact injury of Vertebral Endplates, without Structural Disruption Initiates Disc Degeneration In Vitro

10.21203/rs.3.rs-17192/v1 ◽

2020 ◽

Author(s):

Zhengang Sun ◽

Xiaoshuai Wang ◽

Yongjie Jiang ◽

Guoliang Chen ◽

Zenmin Ling ◽

...

Keyword(s):

Intervertebral Disc ◽

Disc Degeneration ◽

Impact Loading ◽

Degenerative Changes ◽

Single Impact ◽

Spinal Segments ◽

The Impact ◽

Impact Injury ◽

Structural Disruption

Abstract Background : Intervertebral disc degeneration is usually attributed to ageing, genetic, mechanical, and nutritional factors et al. It has been acknowledged that the degenerative process is associated with an aberrant cell-medicated response to structural failures, such as vertebral burst fracture, radial fissures, and endplate fracture. Vertebral endplate trauma, due to, Kirschner wire use or drill holes, can induce degenerative changes of the intervertebral disc (IVD). However, whether a single impact injury of the endplates without structural disruption, which is common seen in the clinic, is sufficiently to initiate disc degeneration is still controversial. This study is to further evolve an in vitro impact injury model of IVD and to investigate if a single impact injury of the endplates without structural disruption can initiate intervertebral disc degeneration(IVDD). Methods. Rats spinal segments (from L1/2 to L5/6, n=54) were harvested and randomly assigned into three groups: Control (n=18), Low Impact (12 J/cm 3 , n=18) and High Impact (25 J/cm 3 , n=18). Samples in both of the impact groups were subjected pure axial impact loading using a custom-made apparatus, and cultured for 14 days. The degenerative process was investigated by using histomorphology and real-time PCR. Results: The discs in both of the impact groups showed significant degenerative changes at 14 days, both of which showed much higher histological scores and up-regulation of the catabolic (MMP-9, MMP-13) genes transcription than that of the control group ( P ＜0.05). The discs with endplate fracture compared to that with intact endplate also showed strongly up-regulated catabolic (MMP-9, MMP-13) genes transcription, and more significant degenerative changes based on the histological scoring ( P ＜0.05). No significant difference of anabolic (TGF-β, Col1α1, Col3α1) genes transcription was found between different groups( P ＞0.05). Conclusion: This study demonstrated that a single impact loading (12 J/cm 3 ) on the spinal segments of the rats could initiate IVDD at 14 days after injury and not only endplate impairment but also a single impact loading without structural disruption could also promote IVDD.

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The Effect of Sorbitol and Conservation Period on The in Vitro Evolution of Solanum Tuberosum L. Plantlets

Cercetari Agronomice in Moldova ◽

10.2478/v10298-012-0058-x ◽

2012 ◽

Vol 45 (3) ◽

pp. 79-86

Author(s):

Iustina Brînduşa Ciobanu ◽

Dana Constantinovici

Keyword(s):

Moisture Content ◽

Impact Energy ◽

Solanum Tuberosum L ◽

Mechanical Damage ◽

Moisture Contents ◽

Significant Difference ◽

Impact Energies ◽

The Impact ◽

Wheat Seeds

Abstract Mechanical damage of seeds due to harvest, handling and other process is an important factor that affects the quality and quantity of seeds. Seed damage result in lower grain value, storability problem, and reduced seed germination and seedling vigor and subsequent yield of crops. The objective of this research was to determine the effects of moisture content and impact energy on the breakage susceptibility of wheat and triticale seeds. The experiments were conducted at five moisture contents of 7.5, 12, 17, 22 and 27% w.b. and at the impact energies of 0.05 and 0.1 J. The percentage of breakage of both wheat and triticale seeds increased as impact energy increased. The analysis of variance showed that there was a significant difference between breakage susceptibility of wheat and triticale seeds at the 1% probability level. Triticale seeds had more breakage than wheat seeds. For both wheat and triticale seeds as the moisture content of the seeds increased, the amount of the percentage breakage of seeds decreased as a polynomial. The average values of percentage breakage of wheat seeds decreased from 43.81 to 19.88% as the moisture content increased from 7.5 to 27%. Over this same moisture content range the percentage breakage of triticale seeds varied from 81.34 to 37.77%. Below the moisture contents of 17% for the wheat and 22% for the triticale the percentage breakage of seeds increased dramatically.

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Study on Vibration Response of Layered Media under the Impact Load

Shock and Vibration ◽

10.1155/2021/4161545 ◽

2021 ◽

Vol 2021 ◽

pp. 1-21

Author(s):

Mengyang Zhen ◽

Jun Liu ◽

Zhimin Xiao ◽

Futian Zhao ◽

Yue Wang ◽

...

Keyword(s):

Impact Energy ◽

Impact Loading ◽

Layered Medium ◽

Impact Load ◽

Layered Media ◽

Vibration Response ◽

Vibration Velocity ◽

Concrete Slabs ◽

Peak Response ◽

The Impact

To study the vibration response of the layered medium under impact loading, single-layer concrete slabs, multilayer concrete slabs, and multilayer concrete slabs with a cemented filling layer were used as the working media to simulate the layered medium. A large number of impact loading tests were carried out by using a simple drop hammer device designed by us. The experimental results indicate that, under the impact load, the vibration response of the surface of the medium decreases with the increase in the distance to the impact source, showing the law of fast attenuation near field and slow attenuation far field, and the vibration energy moves to the low-frequency component; the vibration response increases with the increase in the impact energy, and the difference in the vibration response caused by the impact energy decreases as the distance increases; the vibration response is negatively correlated with the thickness of the dielectric layer, and the divergence of vibration response caused by impact energy decreases with the increase in the thickness of the dielectric layer. Due to the existence of the free surface and bedding, the vibration response of the layered medium surface increases with the increase in the number of layers and the vibration velocity response increases with the increase in the distance to the impact source when it is close to the free surface and far from the vibration source. For the filling of the cemented layer, the vibration response of the layered concrete slab becomes more complex under impact loading, showing obvious disorder. At the same time, this paper also used the dimensional analysis method to establish the calculation model of the peak response of vibration velocity of layered media under the impact load, which provided an idea for determining the peak response of vibration velocity of the layered media.

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A STUDY ON THE BEHAVIOR OF A THIN STS 304 SHEET WITH A FREE BOUNDARY CONDITIONS SUBJECTED TO IMPACT LOADING

International Journal of Modern Physics B ◽

10.1142/s0217979208050838 ◽

2008 ◽

Vol 22 (31n32) ◽

pp. 5572-5577 ◽

Cited By ~ 1

Author(s):

D. G. AHN ◽

G. J. MOON ◽

C. G. JUNG ◽

D. Y. YANG

Keyword(s):

Free Boundary ◽

Impact Energy ◽

Impact Loading ◽

Three Dimensional ◽

Local Deformation ◽

Drop Impact ◽

Absorption Mechanism ◽

Impact Tests ◽

Deformation Behaviors ◽

The Impact

The objective of this paper is to investigate into impact behaviors of a STS 304 sheet with a thickness of 0.7 mm in a free boundary condition subjected to impact loading by a hemispherical impact head using drop impact tests and the three-dimensional FE analyses. The drop impact tests and the FE analyses were conducted with different impact energy ranging from 37.0 J to 45.7 J. From the results of the impact tests, the influence of the impact energy on the force-deflection curve, the absorption mechanism of the impact energy and deformation behaviors of specimen were examined quantitatively. Through the FE analyses, the variation of stress-strain distributions and characteristics of the local deformation during the impact of the specimen were investigated.

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