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The experimental measurement of biomechanical responses that correlate with blast-induced traumatic brain injury (bTBI) has proven challenging. These data are critical for both the development and validation of computational and physical head models, which are used to quantify the biomechanical response to blast as well as to assess fidelity of injury mitigation strategies, such as personal protective equipment. Therefore, foundational postmortem human surrogate (PMHS) experimental data capturing the biomechanical response are necessary for human model development. Prior studies have measured short-duration pressure transmission to the brain (Kinetic phase), but have failed to reproduce and measure the longer-duration inertial loading that can occur (Kinematic phase). Four fully instrumented PMHS were subjected to short-duration dynamic overpressure in front-facing and rear-facing orientations, where intracranial pressure (ICP), global head kinematics, and brain motion (as measured by high-speed X-ray) with respect to the skull were recorded. Peak ICP results generally increased with increased dose, and a mirrored pressure response was seen when comparing the polarity of frontal bone versus occipital bone ICP sensors. The head kinematics were delayed when compared to the pressure response and showed higher peak angles for front-facing tests as compared to rear-facing. Brain displacements were approximately 2–6 mm, and magnitudes did not change appreciably between front- and rear-facing tests. These data will be used to inform and validate models used to assess bTBI.

Silos are strategic structures widespread in the industrial sectors for post-harvest preservation purposes. Current standards on the seismic design of silos are understandably based on approximate and simplified assumptions, leading intentionally to conservative design-oriented formulae. However, unjustified over-estimation might lead to unnecessary economic losses. As part of the authors’ analytical and experimental ongoing research on the complex seismic behavior of filled silo systems, in this short paper, an in-depth reading of the theoretical framework originally proposed during the 1970s and 1980s is provided to present a better understanding of the unexplained design-oriented formula of the seismic additional pressure in the European standard. A conceptual incongruence in the Eurocode EN1998-4:2006 is pointed out and discussed regarding the dynamic overpressure formula in the case of ground-supported flat-bottom circular silos subjected to seismic excitation. Specifically, a potential miscounting of the geometrical aspect in circular silos, with respect to rectangular ones, leads to an inconsistent amplification of the additional pressures in the range 1.65–2, depending on the filling aspect ratio of the silo. This inconsistency provides the reason for several unexplained results recently published in the scientific literature. A proposal for a physically based correction, retaining the current assumptions made by the EN1998-4, is finally given.

To calculate the dynamic peak overpressure of the shock wave of a shell-packed charge and assess their blasting power, this paper constructed a function relationship between terminal velocity, loading ratio, test point position, and equivalent charge mass based on the test result and the dynamic scattering characteristics of explosive products. This model quantifies the effect of terminal ballistic parameters on the dynamic peak overpressure of shock waves for the first time, and the error between the model calculation result and the experimental result is less than 12%. In addition, by reconstructing the dynamic peak overpressure space-time field of shock waves and analyzing the influence of terminal ballistic parameters on dynamic peak overpressure of shock wave, it was found that the height had the biggest influence on the dynamic peak overpressure of shock wave with the influence coefficient of -11896 Pa/m, followed by the fall angle with the influence coefficient of 37.4 Pa/°, and then the terminal velocity with the influence coefficient of 16.6 Pa/(m/s).

Understanding the dynamic characteristics of deep-sea explosions is essential to improve the survivability and combat capability of deep-sea equipment. In this paper, by considering the practical underwater conditions, we investigated the mechanical effects of the deep-sea 1-kg-trinitrotoluene (TNT) explosion with charge depths ranging from 1 to 10 km through numerical simulation and dimensional analysis. The shock wave overpressure, the positive overpressure pulse, the bubble pulse, and the energy distribution for various depth explosions were analyzed systematically. The simulation results showed that the charge depth was negligible for the peak overpressure of the shock wave. However, the positive overpressure pulse, the shock wave energy, the maximum bubble radius, the bubble energy, and the bubble period decrease significantly with increasing the charge depth. Then, the dimensional analysis for deep-sea TNT explosion was performed to reveal the key dimensionless parameters, from which the scaling laws of the shock wave overpressure and the overpressure pulse were obtained. By fitting the simulation results, the dimensionless equations were proposed, providing an effective method for predicting the peak overpressure and the positive overpressure pulse of shock wave for underwater TNT explosion over a wide range of water depths.

To investigate the dynamic response of square cabin under blast loading, three static explosion experiments were conducted on a small polyhedral structure square cabin. The TNT equivalent weights used were 1.04kg, 2.04kg, and 3.04kg, at distances of 1m, 0.8m, and 1.7m, respectively. The free-field overpressure sensor was employed to record the overpressure generated by the explosion, and the dynamic response of the square cabin structure under the blast loading was analyzed. Results show that the distribution of the square cabin skeleton and the quantity of equipment have a significant impact on the dynamic response of the square cabin. The research findings have important reference value for the application scope of square cabins on the battlefield.

An integrated fire-resistant and explosion-proof blockage structure has been designed for the valve hall bushing hole of the Qinyang ±800 kV large converter transformer. The structure consists of a stainless steel plate, zirconium silicate board, inorganic fireproof board, nano-insulation board, and a stainless steel square tube support structure. A three-dimensional numerical simulation analysis was conducted based on explicit dynamics methods. The results show that the designed fire-resistant and explosion-proof integrated blockage structure exhibits repeated oscillations under the effect of a peak overpressure of 800 kPa from the explosion shock wave. The maximum instantaneous deformation of the surface of the explosion-proof structure and the internal skeleton support structure is 4.71 mm, with no damage or fracture occurring. The structure can effectively withstand the aforementioned explosion shock wave overpressure. This research provides an important reference for the fire-resistant and explosion-proof engineering design of ultra-high voltage converter stations.

In this study, the effect of industrial-scale reactor vent size on pressure relief efficiency and reactor design was investigated using the computational fluid dynamics (CFD) method. The thermal decomposition and venting process of di-tert-butyl peroxide (DTBP) were simulated to analyze the temperature and pressure distributions at different time points (1s, 20s, 40s, and 50s) under different vent sizes (32mm, 48mm, 64mm, 96mm, 128mm, 160mm, and 192mm). The results show that vent size significantly affects venting efficiency, with larger vents more effectively reducing internal pressure and mitigating the risk of overpressure. Additionally, the study highlights the crucial role of vent size in reactor design optimization, providing valuable insights for the safe design of industrial reactors and the enhancement of pressure relief systems.

A combination of geological evidence (in the form of hydrothermal vein systems in exhumed fault systems) and geophysical information around active faults supports the localized invasion of near-lithostatically overpressured aqueous fluids into lower portions of the crustal seismogenic zone which commonly extends to depths between 10 and 20 km. This is especially the case for compressional–transpressional tectonic regimes which, beside leading to crustal thickening and dewatering through prograde metamorphism, are also better at containing overpressure and are ‘load-strengthening’ (mean stress rising with increasing shear stress), the most extreme examples being associated with areas undergoing active compressional inversion where existing faults are poorly oriented for reactivation. In these circumstances, ‘fault-valve’ action from ascending overpressured fluids is likely to be widespread with fault failure dual-driven by a combination of rising fluid pressure in the lower seismogenic zone lowering fault frictional strength, as well as rising shear stress. Localized fluid overpressuring nucleates ruptures at particular sites, but ruptures on large existing faults may extend well beyond the regions of intense overpressure. Postfailure, enhanced fracture along fault rupture zones promotes fluid discharge through the aftershock period, increasing fault frictional strength before hydrothermal sealing occurs and overpressures begin to reaccumulate. The association of rupture nucleation sites with local concentrations of fluid overpressure is consistent with selective invasion of overpressured fluid into the roots of major fault zones and with observed non-uniform spacing of major hydrothermal vein systems along exhumed brittle–ductile shear zones. A range of seismological observations in compressional–transpressional settings are compatible with this hypothesis. There is a tendency for large crustal earthquakes to be associated with extensive (L ~ 100–200 km) low-velocity zones in the lower seismogenic crust, with more local Vp/Vs anomalies (L ~ 10–30 km) associated with rupture nucleation sites. In some instances, these low-velocity zones also exhibit high electrical conductivity. Systematic, rigorous evaluation is needed to test how widespread these associations are in different tectonic settings, and to see whether they exhibit time-dependent behaviour before and after major earthquake ruptures.

There is a strong spatial correlation between submarine slope failures and the occurrence of gas hydrates. This has been attributed to the dynamic nature of gas hydrate systems and the potential reduction of slope stability due to bottom water warming or sea level drop. However, 30 years of research into this process found no solid supporting evidence. Here we present new reflection seismic data from the Arctic Ocean and numerical modelling results supporting a different link between hydrates and slope stability. Hydrates reduce sediment permeability and cause build-up of overpressure at the base of the gas hydrate stability zone. Resulting hydro-fracturing forms pipe structures as pathways for overpressured fluids to migrate upward. Where these pipe structures reach shallow permeable beds, this overpressure transfers laterally and destabilises the slope. This process reconciles the spatial correlation of submarine landslides and gas hydrate, and it is independent of environmental change and water depth. There is a strong correlation between submarine slope failures and the occurrence of gas hydrates. Here, the authors use a combination of seismic data and numerical modelling to show that overpressure at the gas hydrate stability zone leads to potential destabilization of the slope and submarine landslides.

Evidence suggests that low-level blast (LLB) overpressure exposure from military heavy weapons training is associated with subclinical adverse brain health and performance (H &P) outcomes. Existing DOD safety policies related to blast overpressure exposure are not specific to LLB-related brain health effects. This study sought to synthesize the available literature and analyze the relevancy of a specific blast metric to LLB exposures and the manifestation of adverse brain H &P outcomes. A literature search yielded 311 unique articles, from which 220 were identified as human studies on LLB published from 2010 to 2021. After more exhaustive exclusion criteria were applied, 14 articles met the criteria for inclusion. Findings on brain H &P changes were examined in relation to quantified LLB measurements (e.g., peak overpressure) to identify trends. Overall, the included studies suggested that alterations of reaction time, a metric for neurocognitive performance, as well as symptom reporting can occur following cumulative LLB exposures above 4 psi (27.6 kPa). Biomarkers and neurosensory changes have not demonstrated consistent associations with LLB exposures. These findings suggest that cumulative blast overpressure exposures above 4 psi (27.6 kPa) based on current measurement methodologies for body-worn sensors may be associated with adverse brain H &P outcomes. Current research efforts seek to better quantify LLB exposure, the relationships between LLB (e.g., intensity, duration, dose) and brain health, as well as to assess brain H &P domains more comprehensively. These efforts will serve to promote a better understanding of the interaction between LLB exposures and adverse brain H &P outcomes.