Vertical accelerator device to apply loads simulating blast environments in the military to human surrogates

Yoganandan, Narayan; Pintar, Frank A.; Schlick, Michael; Humm, John; Merkle, Andrew C.; Kleinberger, Michael

doi:10.1016/j.jbiomech.2015.06.008

Cited by 31 publications

(5 citation statements)

References 11 publications

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“…Model simulations were then run to investigate the utility of the FE model to assess countermeasures. Specifically, the protection offered by the Meindl combat boot was assessed over a range of loading conditions representative of UBB ( Gallenberger et al, 2013 ; Bailey et al, 2015 ; Yoganandan et al, 2015 ; Pietsch et al, 2016 ; Baker et al, 2017 ). The material parameters used for the combat boot were calculated based on the fit of experimental data obtained in a previous study ( Newell et al, 2016 ).…”

Section: Methodsmentioning

confidence: 99%

“…Peak velocity ranged from 5 to 17.5 m/s with time to peak between 1.5 and 9 ms. These values were based on the acceleration profiles reported in the literature ( Henderson et al, 2013 ; Bailey et al, 2015 ; Yoganandan et al, 2015 ; Pietsch et al, 2016 ; Yoganandan and Chirvi, 2016 ; Baker et al, 2017 ). The velocity profile was modeled as a triangular shape according to the required combination of peak impact velocity and time to peak.…”

Section: Methodsmentioning

confidence: 99%

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An Experimentally Validated Finite Element Model of the Lower Limb to Investigate the Efficacy of Blast Mitigation Systems

Rebelo

Grigoriadis

Carpanen

et al. 2021

Front. Bioeng. Biotechnol.

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Improvised explosive devices (IEDs) used in the battlefield cause damage to vehicles and their occupants. The injury burden to the casualties is significant. The biofidelity and practicality of current methods for assessing current protection to reduce the injury severity is limited. In this study, a finite-element (FE) model of the leg was developed and validated in relevant blast-loading conditions, and then used to quantify the level of protection offered by a combat boot. An FE model of the leg of a 35 years old male cadaver was developed. The cadaveric leg was tested physically in a seated posture using a traumatic injury simulator and the results used to calibrate the FE model. The calibrated model predicted hindfoot forces that were in good correlation (using the CORrelation and Analysis or CORA tool) with data from force sensors; the average correlation and analysis rating (according to ISO18571) was 0.842. The boundary conditions of the FE model were then changed to replicate pendulum tests conducted in previous studies which impacted the leg at velocities between 4 and 6.7 m/s. The FE model results of foot compression and peak force at the proximal tibia were within the experimental corridors reported in the studies. A combat boot was then incorporated into the validated computational model. Simulations were run across a range of blast-related loading conditions. The predicted proximal tibia forces and associated risk of injury indicated that the combat boot reduced the injury severity for low severity loading cases with higher times to peak velocity. The reduction in injury risk varied between 6 and 37% for calcaneal minor injuries, and 1 and 54% for calcaneal major injuries. No injury-risk reduction was found for high severity loading cases. The validated FE model of the leg developed here was able to quantify the protection offered by a combat boot to vehicle occupants across a range of blast-related loading conditions. It can now be used as a design and as an assessment tool to quantify the level of blast protection offered by other mitigation technologies.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

An Experimentally Validated Finite Element Model of the Lower Limb to Investigate the Efficacy of Blast Mitigation Systems

Rebelo

Grigoriadis

Carpanen

et al. 2021

Front. Bioeng. Biotechnol.

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“…This was accomplished using a pendulum or a custom vertical accelerator apparatus, termed the Vertac device. 42 A schematic of the devices is shown (Figs. 1 and 2).…”

Section: Alignment and Loadingmentioning

confidence: 99%

Foot–Ankle Fractures and Injury Probability Curves from Post-mortem Human Surrogate Tests

et al. 2016

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This purpose of this study was to replicate foot-ankle injuries seen in the military and derive human injury probability curves using the human cadaver model. Lower legs were isolated below knee from seventeen unembalmed human cadavers and they were aligned in a 90-90 posture (plantar surface orthogonal to leg). The specimens were loaded along the tibia axis by applying short-time duration pulses, using a repeated testing protocol. Injuries were documented using pre- and post-test X-rays, computed tomography scans, and dissection. Peak force-based risk curves were derived using survival analysis and accounted for data censoring. Fractures were grouped into all foot-ankle (A), any calcaneus (B), and any tibia injuries (C), respectively. Calcaneus and/or distal tibia/pilon fractures occurred in fourteen tests. Axial forces were the greatest and least for groups C and B, respectively. Times attainments of forces for all groups were within ten milliseconds. The Weibull function was the optimal probability distribution for all groups. Age was significant (p < 0.05) for groups A and C. Survival analysis-based probability curves were derived for all groups. Data are given in the body of paper. Age-based, risk-specific, and continuous distribution probability curves/responses guide in the creation of an injury assessment capability for military blast environments.

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Section: Introductionmentioning

confidence: 99%

“…Various platforms have been developed previously to replicate underbody blast (UBB)—that is, the attack of the underside of a vehicle by explosives—in the laboratory and used to test surrogate lower limbs such as post mortem human surrogates (PMHSs) and anthropometric test devices (ATDs). 1 , 7 , 12 , 13 , 15 , 19 , 21 , 23 , 31 , 46 , 47 To assess injury, the results from these tests have been analysed to develop injury risk functions (IRFs), which relate the probability of injury with the axial force transmitted to the lower limb. 2 , 3 , 23 , 24 , 43 , 45 Although parameters such as age, gender, and bone mineral density, 12 , 45 as well as loading rates and location of measurements have been taken into account when developing IRFs, 2 the effect of the posture of the occupant at the time of the attack on the injurious outcome has not.…”

Section: Introductionmentioning

confidence: 99%

Lower Limb Posture Affects the Mechanism of Injury in Under-Body Blast

et al. 2018

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Over 80% of wounded Service Members sustain at least one extremity injury. The ‘deck-slap’ foot, a product of the vehicle’s floor rising rapidly when attacked by a mine to injure the limb, has been a signature injury in recent conflicts. Given the frequency and severity of these combat-related extremity injuries, they require the greatest utilisation of resources for treatment, and have caused the greatest number of disabled soldiers during recent conflicts. Most research efforts focus on occupants seated with both tibia-to-femur and tibia-to-foot angles set at 90°; it is unknown whether results obtained from these tests are applicable when alternative seated postures are adopted. To investigate this, lower limbs from anthropometric testing devices (ATDs) and post mortem human subjects (PMHSs) were loaded in three different seated postures using an under-body blast injury simulator. Using metrics that are commonly used for assessing injury, such as the axial force and the revised tibia index, the lower limb of ATDs were found to be insensitive to posture variations while the injuries sustained by the PMHS lower limbs differed in type and severity between postures. This suggests that the mechanism of injury depends on the posture and that this cannot be captured by the current injury criteria. Therefore, great care should be taken when interpreting and extrapolating results, especially in vehicle qualification tests, when postures other than the 90°–90° are of interest.

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Vertical accelerator device to apply loads simulating blast environments in the military to human surrogates

Cited by 31 publications

References 11 publications

An Experimentally Validated Finite Element Model of the Lower Limb to Investigate the Efficacy of Blast Mitigation Systems

An Experimentally Validated Finite Element Model of the Lower Limb to Investigate the Efficacy of Blast Mitigation Systems

Foot–Ankle Fractures and Injury Probability Curves from Post-mortem Human Surrogate Tests

Lower Limb Posture Affects the Mechanism of Injury in Under-Body Blast

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