Dataset Information

Influence of impact velocity and impact attack angle of bullets on damage of human tissue surrogate -- ballistic gelatin.

ABSTRACT:

Purpose

Terminal performance of a bullet in human body is critical for the treatment of gunshot injury and optimization of bullet design. The effects of the impact velocity (v₀) and the impact attack angle (δ₀) of the bullet on its terminal performance was investigated, using a new evaluation method (called expansion method) based on the expansion of cracks and the permanent cavity wall in ballistic gelatin.

Methods

Ballistic gelatin was used to simulate human body. The 7.62 mm × 39 mm rifle bullets with different v₀ (600-760 m/s) and δ₀ (0°-6°) were fired into the gelatin blocks. The gelatin block was cut into slices of about 20 mm thickness. The cracks and the permanent cavity on each slice were obtained manually. The damaged gelatin was determined using two methods: expanding the permanent cavity but ignoring the cracks, and expanding both the permanent cavity and the cracks. The relations between the damaged gelatin and v₀ and δ₀ were obtained using linear fitting method.

Results

According to the distribution of the damaged gelatin along the penetration depth, the damaged gelatin block could be divided into two parts: the less damaged part and the severely damaged part. The length of the less damaged part depends mostly on δ₀; while the average damaged area of this part depends on both δ₀ as well as v₀. The cracks contributed significantly to the total volume of damaged gelatin, particularly when the expansion was larger than 1.9 mm. The total damaged gelatin increases with v₀, δ₀ and the expansion extent. The average length of equivalent cracks grew with v₀ and δ₀ when considering the cracks, and decreased with v₀ when ignoring the cracks.

Conclusion

The expansion method is suitable to investigate the influence of different factors of bullets on their terminal performance. The characteristics of the damaged gelatin have a linear relationship with the initial attack angle (δ₀) and the initial velocity (v₀) of the bullet.

SUBMITTER: Mo GL

PROVIDER: S-EPMC9252937 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Introduction and importanceVulvar penetrating trauma is a rather uncommon occurrence (1). Firearm injuries caused by low-velocity gravitational bullets are a common cause of injuries in war-torn countries such as Somalia [2] (Campbell and Wilbert, 2022). These types of injuries are inflicted on by-standers by wayward bullets. No standard consensus on the appropriate management of vulvar penetrating trauma has been established (3). Here in, we report the successful management of an impacted bullet in the clitoris by a simple incision under local anesthesia. The principles of vulva and clitoris tired bullet trauma management are discussed. In our case, we thought it to be rare and interesting, considering its occurrence.Case presentationIn this report, a 24-year-old woman (gravida 2, para 2) suffered from a vulvar area penetrating bullet injury. Imaging revealed that the foreign body was confined to the clitoris, and no evidence of other parts of the body. Under local anesthesia, the bullet was accessed and removed from the clitoris by performing a minor incision. No complications were observed following the surgical removal of the bullet.Clinical discussionNon-obstetric vulva trauma is an extremely rare occurrence. Typically, the cause of non-obstetric vulvar trauma includes sports-related injuries, straddle injuries, and midline splitting injuries. To the best of our knowledge, this case is unique due to the bullet being retained in the clitoris. The treatment of the foreign body is mostly surgical removal. Under local anesthesia, this patient underwent complete surgical removal of the metallic foreign body. During surgical excision, care should be taken not to damage the urethra and other pelvic issues.ConclusionTo the best of our knowledge, this is the first wayward bullet (not intended for the patient) injury penetrating the vulvar area with a retained bullet in the clitoris. In our case, we thought it to be rare and interesting, considering its occurrence.

Project description:In this work, a near β-type Ti5.1Al2.5Cr0.5Fe4.5Mo1.1Sn1.8Zr2.9Zn alloy was hot-rolled at the temperature of 800-880 °C with a thickness reduction of 87.5% and then heat-treated with the strategy of 880 °C/1 h/air cooling (AC) + 650 °C/3 h/AC. The microstructure difference between the hot-rolled and heat-treated titanium alloys and its influence on the ballistic impact behavior of the hot-rolled and heat-treated titanium alloys were analyzed. The microstructural investigation revealed that the average size of the acicular secondary α phase (αs) dropped from 75 to 42 nm, and the corresponding amount of this phase increased significantly after heat treatment. In addition, the dislocation density of the α and β phases decreased from 0.3340 × 1015/m2 and 4.6746 × 1015/m2 for the hot-rolled titanium alloy plate to 0.2806 × 1015/m2 and 1.8050 × 1015/m2 for the heat-treated one, respectively. The high strength of the heat-treated titanium alloy was maintained, owing to the positive contribution of the acicular secondary α phase. Furthermore, the critical fracture strain increased sharply from 19.9% for the hot-rolled titanium alloy plate to 23.1% for the heat-treated one, thereby overcoming (to some extent) the constraint of the strength-ductility trade-off. This is mainly attributed to the fact that the dislocation density and the difference between the dislocation densities of the α and β phases decreased substantially, and deformation localization was effectively suppressed after heat treatment. Damage to the hot-rolled and heat-treated titanium alloy plates after the penetration of a 7.62 mm ordinary steel core projectile at a distance of 100 m was assessed via industrial computer tomography and microstructure observation. The results revealed that a large crack (volume: 2.55 mm3) occurred on the rear face and propagated toward the interior of the hot-rolled titanium alloy plate. The crack tip was connected to a long adiabatic shear band with a depth of 3 mm along the thickness direction. However, good integrity of the heat-treated titanium alloy plate was maintained, owing to its excellent deformation capability. Ultimately, the failure mechanism of the hot-rolled and heat-treated titanium alloy plates was revealed by determining the crack-forming reasons in these materials.