scholarly journals Simulation of Bullet Fragmentation and Penetration in Granular Media

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5243
Author(s):  
Froylan Alonso Soriano-Moranchel ◽  
Juan Manuel Sandoval-Pineda ◽  
Guadalupe Juliana Gutiérrez-Paredes ◽  
Usiel Sandino Silva-Rivera ◽  
Luis Armando Flores-Herrera
Keyword(s):  
Kinetic Energy ◽  
Granular Media ◽  
Elastic Collision ◽  
Smooth Particle Hydrodynamics ◽  
X Ray ◽  
Bullet Fragmentation ◽  
Particle Hydrodynamics ◽  
The Moment ◽  
Physical Phenomena ◽  
The Impact

The aim of this work is to simulate the fragmentation of bullets impacted through granular media, in this case, sand. In order to validate the simulation, a group of experiments were conducted with the sand contained in two different box prototypes. The walls of the first box were constructed with fiberglass and the second with plywood. The prototypes were subjected to the impact force of bullets fired 15 m away from the box. After the shots, X-ray photographs were taken to observe the penetration depth. Transient numerical analyses were conducted to simulate these physical phenomena by using the smooth particle hydrodynamics (SPH) module of ANSYS® 2019 AUTODYN software. Advantageously, this module considers the granular media as a group of uniform particles capable of transferring kinetic energy during the elastic collision component of an impact. The experimental results demonstrated a reduction in the maximum bullet kinetic energy of 2750 J to 100 J in 0.8 ms. The numerical results compared with the X-ray photographs showed similar results demonstrating the capability of sand to dissipate kinetic energy and the fragmentation of the bullet caused at the moment of impact.

scholarly journals Collision and impact simulations including porosity

2006 ◽  
Vol 2 (S236) ◽  
pp. 223-231 ◽  
Author(s):  
Willy Benz ◽  
Martin Jutzi
Keyword(s):  
High Velocity ◽  
Numerical Approach ◽  
Smooth Particle Hydrodynamics ◽  
Deep Impact ◽  
Fracture Threshold ◽  
Porous Bodies ◽  
Brittle Solids ◽  
Particle Hydrodynamics ◽  
Impact Simulations ◽  
The Impact

AbstractThe Smooth Particle Hydrodynamics (SPH) impact code (Benz & Asphaug 1994) has been developed for the simulation of impacts and collisions involving brittle solids in the strength-and gravity-dominated regime. In the latter regime, the gravitational overburden is used to increase the fracture threshold. In this paper, we extend our numerical approach to include the effect of porosity at a sub-resolution scale by adapting the so-called P -α model (Herrman 1969). Using our extended 3D SPH impact code, we investigated collisions between porous bodies to examine the sensitivity of collisional outcomes to the degree of porosity. Two applications that illustrate the capabilities of our approach are shown: 1) the modeling of a Deep Impact-like impact and 2) the computation of the amount of momentum transferred to an asteroid following the impact of a high velocity projectile.

Computational Aspects of Submarine Slide Generated Tsunami

2014 ◽  
Vol 567 ◽  
pp. 216-221 ◽  
Author(s):  
Vo Nguyen Phu Huan ◽  
Indra Sati Hamonangan Harahap
Keyword(s):  
Incompressible Flows ◽  
Smooth Particle Hydrodynamics ◽  
Sph Method ◽  
Simulation Methodology ◽  
Submarine Slide ◽  
Tsunami Waves ◽  
Impact Forces ◽  
Particle Hydrodynamics ◽  
Computational Aspects ◽  
The Impact

Submarine landslide is the most serious threat on both local and regional scales. Tsunami phenomenon induced by submarine slide has put us on the challenge in understanding from generation mechanism to propagation and coastal inundation and mitigating the risk from submarine slide generated tsunami. This research presents the numerical simulation methodology by Smooth Particle Hydrodynamics (SPH) to investigate the impact forces of tsunami waves with the aid of physical modeling. By using parallelSPHysics, it is a source code based on the SPH method to model nearly‐incompressible flows, including various physical processes. The conclusions may potentially be taken as guideline of mitigate the risk from tsunami wave.

scholarly journals Computational ballistic analysis of the cranial shot to John F. Kennedy

2021 ◽  
Author(s):  
Christophe Then
Keyword(s):  
Head Injury ◽  
Mathematical Models ◽  
High Speed ◽  
Human Head ◽  
Supersonic Speed ◽  
Fracture Characteristics ◽  
X Ray ◽  
High Speed Impact ◽  
Bullet Fragmentation ◽  
The Impact

Almost 60 years after the assassination of John F. Kennedy in 1963 the majority of Americans are still reluctant to believe the official reports of commissions from 1964 and again in 1976 that determined the direction of the shot resulting in the fatal head injury. Long-withheld, confidential government files released in 2017 reignited the controversy.The present investigation computationally simulated projectile-skull impacts from the direction specified in official reports and from three other directions. Detailed geometric models of the human head and ammunition, as well as known parameters from the assassination site served as the supportive base for analysis. Constitutive mathematical models for the impact of projectile material with skull tissues at supersonic speed were employed to analyze bone and bullet fragmentation mechanics. Simulated fracture characteristics of the bone and the bullet were compared with photographic and X-ray evidence. The most likely origin of the fatal shot was determined based on the degree of corresponding deformation and fragmentation between simulation and documented evidence. Computational corroboration could be established as physically consistent with high-speed impact from the rear, as established by the official commissions. Simulations of three other speculative shot origins did not correspond to the documented evidence.

scholarly journals Correlation of Eu L X-ray yield with kinetic energy based on the impact of Eu20+ on solid Au target

2014 ◽  
Vol 63 (16) ◽  
pp. 163202
Author(s):  
Li Yao-Zong ◽  
Zhang Xiao-An ◽  
Liang Chang-Hui ◽  
Zhao Yong-Tao ◽  
Zhou Xian-Ming
Keyword(s):  
Kinetic Energy ◽  
X Ray ◽  
The Impact

Simulation Analysis and Material Optimization of an Aircraft Wing Leading Edge When Subjected to an Artificial Bird Strike

2015 ◽  
Vol 10 (5) ◽  
Author(s):  
K. Srinivasan ◽  
Channankaiah ◽  
George P. Johnson
Keyword(s):  
Simulation Analysis ◽  
Leading Edge ◽  
Primary Objective ◽  
Impact Behavior ◽  
Bird Strike ◽  
Smooth Particle Hydrodynamics ◽  
Sph Method ◽  
Material Optimization ◽  
Particle Hydrodynamics ◽  
The Impact

Bird strike resistance is a strict certification requirement in aircraft industries, and the Federal Aviation Regulations specifically gives various specifications to be followed for certification of various parts of the aircraft. The primary objective of this research is to develop a methodology, which can be utilized to certify an aircraft for bird strike using computational methods, and the impact behavior of a 4-lb artificial bird impinging on the wing leading edge is performed using smooth particle hydrodynamics (SPH) method. The study is focused on the most-frequently used bird configuration in the literatures: namely, cylinder with hemispherical ends. The skin is modeled with an aluminum 2014 alloy, which is prominently used in aircraft industries, and aluminum 8090 alloy. The effects of impact on these materials are studied.

scholarly journals Response Analysis of Submerged Floating Tunnel Hit by Submarine Based on Smoothed-Particle Hydrodynamics

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Gang Luo ◽  
Shaokang Pan ◽  
Yulong Zhang ◽  
Liang Chen
Keyword(s):  
Kinetic Energy ◽  
Smoothed Particle Hydrodynamics ◽  
Coupling Method ◽  
Response Analysis ◽  
Initial Kinetic Energy ◽  
Kinematic Parameters ◽  
Particle Hydrodynamics ◽  
Submerged Floating Tunnel ◽  
Smoothed Particle ◽  
The Impact

This paper presents the theoretical investigation on the damage of the submerged floating tunnel (SFT) under extreme loads. Water was modeled by smoothed-particle hydrodynamics (SPH). Anchor cables, SFT, and submarine were modeled by the finite element method (FEM). Penetrating phenomenon in the calculation process was achieved by the penalty function, and the fluid-solid coupling effect was also considered in the simulation. The process of a submarine striking on the SFT was studied based on the commercial software. The relationships between the energy of the water, submarine, and SFT were studied. The structural and human damages were evaluated using the kinematics and kinetic parameters of the SFT according to the relevant criterion. The results indicate that the SPH-FEM coupling method is suitable to investigate the impact of the SFT in the water. The initial kinetic energy of the submarine is mainly converted into kinetic energy of the water and internal energy of the tunnel. The kinematic parameters at the impact point reach a peak value. The kinematic parameters at the anchor cables reach the minimum value, so the anchor cables can inhibit the development of disaster significantly. The SPH-FEM coupling method can be helpful for collision and explosion analysis of the SFT.

scholarly journals Prediction procedure for hail impact

2018 ◽  
Vol 183 ◽  
pp. 01046
Author(s):  
Simon Dousset ◽  
Jérémie Girardot ◽  
Frédéric Dau ◽  
Augustin Gakwaya
Keyword(s):  
High Strain ◽  
Impact Force ◽  
Smooth Particle Hydrodynamics ◽  
Mesh Distortion ◽  
Sph Method ◽  
Experimental Procedure ◽  
Time Space ◽  
Particle Hydrodynamics ◽  
Impact Simulations ◽  
The Impact

The constant increase of composite materials’ performances makes them more and more used in recent aircrafts. Structures, as the wings or the fuselage, may suffer from hail impacts that can make critical damages or even perforate them. In order to guaranty the safety of passengers, aircrafts have to be certified and simulations have to demonstrate good agreements with real behaviour of the structures and the hail projectile. The aim of this work is to propose a procedure to analyse the home made manufacturing of the ice generally performed in laboratories, its mechanical characterization and a mechanical model that can predict the time-space profile of the impact force on a rigid structure. Because of the high strain level of the hail during the impact, the Smooth Particle Hydrodynamics (SPH) method will be used. Indeed, the finite elements method needs heavy remeshing that are time consuming to avoid mesh distortion. The SPH is a numerical meshless method that calculates interactions between particles at every time increment. Models available in the literature have been studied and the model of J.D. Tippmann (Tippmann, Kim, et Jennifer D. Rhymer 2013) is chosen. In this paper, the Tippman model is presented with its solving using the SPH. A parametric study is proposed in order to catch the relevant parts of this model. A simple experimental procedure is then proposed to feed the model and the results of impact simulations at different velocities are compared to experimental measurements realized in the laboratory.

Analyzing the Impact of X-Ray Tomography on the Reliability of Integrated Circuits

2015 ◽  
Author(s):  
Halit Dogan ◽  
Md Mahbub Alam ◽  
Navid Asadizanjani ◽  
Sina Shahbazmohamadi ◽  
Domenic Forte ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Integrated Circuit ◽  
3D Imaging ◽  
Three Dimensional ◽  
Serial Sectioning ◽  
Promising Technique ◽  
Flash Memories ◽  
X Ray ◽  
3D Information ◽  
The Impact

Abstract X-ray tomography is a promising technique that can provide micron level, internal structure, and three dimensional (3D) information of an integrated circuit (IC) component without the need for serial sectioning or decapsulation. This is especially useful for counterfeit IC detection as demonstrated by recent work. Although the components remain physically intact during tomography, the effect of radiation on the electrical functionality is not yet fully investigated. In this paper we analyze the impact of X-ray tomography on the reliability of ICs with different fabrication technologies. We perform a 3D imaging using an advanced X-ray machine on Intel flash memories, Macronix flash memories, Xilinx Spartan 3 and Spartan 6 FPGAs. Electrical functionalities are then tested in a systematic procedure after each round of tomography to estimate the impact of X-ray on Flash erase time, read margin, and program operation, and the frequencies of ring oscillators in the FPGAs. A major finding is that erase times for flash memories of older technology are significantly degraded when exposed to tomography, eventually resulting in failure. However, the flash and Xilinx FPGAs of newer technologies seem less sensitive to tomography, as only minor degradations are observed. Further, we did not identify permanent failures for any chips in the time needed to perform tomography for counterfeit detection (approximately 2 hours).

scholarly journals The role of point-of-care ultrasound in the diagnosis of pericardial effusion: a single academic center retrospective study

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Matthew G. Hanson ◽  
Barry Chan
Keyword(s):  
Pericardial Effusion ◽  
Point Of Care ◽  
Physical Exam ◽  
Right Atrial ◽  
Point Of Care Ultrasound ◽  
X Ray ◽  
Average Systolic Blood Pressure ◽  
Time To Diagnosis ◽  
Clinically Significant ◽  
The Impact

Abstract Background Symptomatic pericardial effusion (PCE) presents with non-specific features and are often missed on the initial physical exam, chest X-ray (CXR), and electrocardiogram (ECG). In extreme cases, misdiagnosis can evolve into decompensated cardiac tamponade, a life-threatening obstructive shock. The purpose of this study is to evaluate the impact of point-of-care ultrasound (POCUS) on the diagnosis and therapeutic intervention of clinically significant PCE. Methods In a retrospective chart review, we looked at all patients between 2002 and 2018 at a major Canadian academic hospital who had a pericardiocentesis for clinically significant PCE. We extracted the rate of presenting complaints, physical exam findings, X-ray findings, ECG findings, time-to-diagnosis, and time-to-pericardiocentesis and how these were impacted by POCUS. Results The most common presenting symptom was dyspnea (64%) and the average systolic blood pressure (SBP) was 120 mmHg. 86% of people presenting had an effusion > 1 cm, and 89% were circumferential on departmental echocardiogram (ECHO) with 64% having evidence of right atrial systolic collapse and 58% with early diastolic right ventricular collapse. The average time-to-diagnosis with POCUS was 5.9 h compared to > 12 h with other imaging including departmental ECHO. Those who had the PCE identified by POCUS had an average time-to-pericardiocentesis of 28.1 h compared to > 48 h with other diagnostic modalities. Conclusion POCUS expedites the diagnosis of symptomatic PCE given its non-specific clinical findings which, in turn, may accelerate the time-to-intervention.

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