Experimental study on the high-speed impact of a sand particle on Ti–6Al–4V

2019 ◽  
Vol 234 (4) ◽  
pp. 632-646
Author(s):  
Cheng Yan ◽  
Wei Chen ◽  
Zhenhua Zhao
Keyword(s):  
High Speed ◽  
Impact Damage ◽  
Damage Mechanism ◽  
Impact Angle ◽  
Sand Particle ◽  
Compressor Blades ◽  
Supersonic Airflow ◽  
High Speed Impact ◽  
Sand Particles ◽  
The Impact

When sand is ingested by a helicopter engine, it collides with the compressor blades at a high relative speed, causing severe erosion damage. A test was conducted on the high-speed impact of sand particles on the target of Ti–6Al–4 V alloy to enhance the understanding of high-speed impact damage mechanism. The test apparatus was used to create supersonic airflow, which was produced by normal temperature air flowing through a special Laval nozzle. The supersonic airflow produced the drag force to increase the velocity of sand particles up to about 400 m/s. The experiment demonstrated that fractured sand particle caused less damage than nonfractured particle under similar impact conditions. The nonfractured particle directly cut the target more easily than the fractured at a relatively low impact velocity. When the impact speed exceeded 300 m/s, the crater depth increased exponentially with the increase of velocity. Impact angle determined the mode of material failure.

Solid particle erosion of metals: the removal of surface material by spherical projectiles

1976 ◽  
Vol 348 (1654) ◽  
pp. 379-392 ◽  
Keyword(s):  
High Speed ◽  
Impact Angle ◽  
Solid Particle Erosion ◽  
High Speed Photography ◽  
Surface Material ◽  
Crater Formation ◽  
Particle Erosion ◽  
Sand Particles ◽  
The Impact

Experiments are described in which steel spheres were projected obliquely onto mild steel targets. It is shown that this successfully simulates a class of impact occurring during the erosion of metals by dust and sand particles. The dependence of the crater dimensions on impact angle and velocity is determined and, using high speed photography, the energy balance in the impact process is studied. A model of crater formation is proposed which accurately predicts the volume of material displaced and the energy lost by an impacting sphere. It is found that metal becomes detached along a band of intense subsurface shear; calculation shows that this is associated with the production of local high temperatures. The data and analysis presented provide a basis for assessing the rôle of the ploughing component of deformation in erosion.

Motion Situation and Kinetic Energy Analysis for Ore Pass of Underground Mine

2011 ◽  
Vol 90-93 ◽  
pp. 383-386
Author(s):  
Yong Heng Huang ◽  
Ping Cao ◽  
Yi Xian Wang
Keyword(s):  
Kinetic Energy ◽  
High Speed ◽  
Impact Damage ◽  
Critical Value ◽  
Impact Angle ◽  
Underground Mine ◽  
Damaged Zone ◽  
Impact Kinetic Energy ◽  
The Impact ◽  
Ore Pass

The fragmentation of ore pass under loading belongs to one of the typical disaster in underground mine. This paper is concerned with the description and explanation of this phenomenon and presents brittle fragmentation for impact damage of rock block based on impact test, high-speed camera was used to study the relation between fragmentation and damage and the effect of the kinetic energy of projectile on them, the experimental results demonstrate that the damaged zone, invasion depth increase with the increase of the kinetic energy of projectile, but are influenced by the impact angle; the results show that prior to the impact kinetic energy reaches the critical value, the energy dissipation is mainly for damaged zone, when the impact kinetic energy increases to the critical value.

Experimental Calibration of ISV Damage Model Constants for Pure Copper for High-Speed Impact Simulation

2016 ◽  
Author(s):  
Yangqing Dou ◽  
Yucheng Liu ◽  
Wilburn Whittington ◽  
Jonathan Miller
Keyword(s):  
High Speed ◽  
Impact Analysis ◽  
Split Hopkinson Pressure Bar ◽  
Internal State ◽  
Pure Copper ◽  
Damage Model ◽  
Hopkinson Pressure Bar ◽  
Experimental Calibration ◽  
High Speed Impact ◽  
The Impact

Coefficients and constants of a microstructure-based internal state variable (ISV) plasticity damage model for pure copper have been calibrated and used for damage modeling and simulation. Experimental stress-strain curves obtained from Cu samples at different strain rate and temperature levels provide a benchmark for the calibration work. Instron quasi-static tester and split-Hopkinson pressure bar are used to obtain low-to-high strain rates. Calibration process and techniques are described in this paper. The calibrated material model is used for high-speed impact analysis to predict the impact properties of Cu. In the numerical impact scenario, a 100 mm by 100 mm Cu plate with a thickness of 10 mm will be penetrated by a 50 mm-long Ni rod with a diameter of 10mm. The thickness of 10 mm was selected for the Cu plate so that the Ni-Cu penetration through the thickness can be well observed through the simulations and the effects of the ductility of Cu on its plasticity deformation during the penetration can be displayed. Also, that thickness had been used by some researchers when investigating penetration mechanics of other materials. Therefore the penetration resistance of Cu can be compared to that of other metallic materials based on the simulation results obtained from this study. Through this study, the efficiency of this ISV model in simulating high-speed impact process is verified. Functions and roles of each of material constant in that model are also demonstrated.

High-speed impacts of slender bodies into non-smooth, complex fluids

2018 ◽  
Vol 861 ◽  
Author(s):  
Ishan Sharma
Keyword(s):  
Penetration Depth ◽  
High Speed ◽  
Complex Fluids ◽  
Laboratory Data ◽  
Impact Speed ◽  
High Speed Impact ◽  
Smooth Complex ◽  
Theoretical Predictions ◽  
Slender Bodies ◽  
The Impact

We present a simple hydrodynamical model for the high-speed impact of slender bodies into frictional geomaterials such as soils and clays. We model these materials as non-smooth, complex fluids. Our model predicts the evolution of the impactor’s speed and the final penetration depth given the initial impact speed, and the material and geometric parameters of the impactor and the impacted material. As an application, we investigate the impact of deep-penetrating anchors into seabeds. Our theoretical predictions are found to match field and laboratory data very well.

Influence of Pipeline Inclination on Hydraulic Conveying of Sand Particles

2012 ◽  
Author(s):  
Ahmed Mohamed Nossair ◽  
Peter Rodgers ◽  
Afshin Goharzadeh
Keyword(s):  
Particle Transport ◽  
High Speed ◽  
Sand Dune ◽  
Sand Particle ◽  
Hydrocarbon Production ◽  
Production Wells ◽  
Load Transport ◽  
Bed Load Transport ◽  
Sand Particles ◽  
Dune Dynamics

The understanding of sand particle transport by fluids in pipelines is of importance for the drilling of horizontal and inclined hydrocarbon production wells, topside process facilities, infield pipelines, and trunk lines. Previous studies on hydraulic conveying of sand particles in pipelines have made significant contributions to the understanding of multiphase flow patterns, pressure drop and particle transport rate in horizontal pipelines. However, due to the complexity of the flow structure resulting from liquid-sand interactions, the mechanisms responsible for bed-load transport flow for hydraulic conveying of sand particles have not been extensively studied in inclined pipelines. This paper presents an experimental investigation of hydraulic conveying of sand particles resulting from a stationary flat bed in both horizontal and +3.6 degree upward inclined pipelines. The characteristics of sand transportation by saltation from an initial sand bed are experimentally visualized using a transparent Plexiglas pipeline and high-speed digital photography. The dune formation process is assessed as a function of pipeline orientation. Based on the visualized dune morphology, pipeline inclination is found to have a significant influence on hydraulic conveying of sand dune dynamics (i.e., dune velocity), as well as sand dune geometry (i.e., dune pitch and characteristic dune angles).

scholarly journals Effect of different helmet shell configurations on the protection against head trauma

2019 ◽  
Vol 54 (7-8) ◽  
pp. 408-415 ◽  
Author(s):  
Marta Palomar ◽  
Ricardo Belda ◽  
Eugenio Giner
Keyword(s):  
Head Trauma ◽  
High Speed ◽  
Composite Shell ◽  
Human Head ◽  
High Rate ◽  
Finite Element Models ◽  
High Speed Impact ◽  
Full Metal Jacket ◽  
The Impact ◽  
Single Combat

Head trauma following a ballistic impact in a helmeted head is assessed in this work by means of finite element models. Both the helmet and the head models employed were validated against experimental high-rate impact tests in a previous work. Four different composite ply configurations were tested on the helmet shell, and the energy absorption and the injury outcome resulting from a high-speed impact with full metal jacket bullets were computed. Results reveal that hybrid aramid–polyethylene configurations do not prevent bullet penetration at high velocities, while 16-layer aramid configurations are superior in dissipating the energy absorbed from the impact. The fabric orientation of these laminates proved to be determinant for the injury outcome, as maintaining the same orientations for all the layers led to basilar skull fractures (dangerous), while alternating orientation of the adjacent plies resulted in an undamaged skull. To the authors knowledge, no previous work in the literature has analysed numerically the influence of different stack configurations on a single combat helmet composite shell on human head trauma.

Simulation Study on Impact Damage of Aircraft Panel Structure under Stress

2006 ◽  
Vol 324-325 ◽  
pp. 391-394
Author(s):  
Man Yi Hou ◽  
Shu Lin Li ◽  
Yang Yi Jiang ◽  
Shou An Li
Keyword(s):  
High Velocity ◽  
Impact Damage ◽  
Damage Mechanism ◽  
Impact Response ◽  
Finite Element Models ◽  
Compression Stress ◽  
High Velocity Impact ◽  
Simulation Results ◽  
Stress States ◽  
The Impact

Based on ANSYS/LS-DYNA code, the finite-element models were created to simulate the response of the aircraft panel structure impacted by high velocity projectile. The models proved to be effective through the comparison between the results of simulation and relative experiments. Then the impact process was simulated respectively considering the states of various types of stress in the panel. Through analyzing the simulation results, the influence of various stress states in the panel on impact response and damage mechanism was summed up. The conclusions indicated that the stress and particularly compression stress in aircraft panel structure can facilitate much more deformation and damage when the panel suffers high velocity impact.

Evaluation of the Impact Formulae for Rigid Projectile Striking on Concrete Target

2011 ◽  
Vol 368-373 ◽  
pp. 894-900 ◽  
Author(s):  
Hao Wu ◽  
Qin Fang
Keyword(s):  
Penetration Depth ◽  
Empirical Formula ◽  
High Strength Concrete ◽  
High Speed ◽  
High Strength ◽  
Local Damage ◽  
High Speed Impact ◽  
Rigid Projectile ◽  
Semi Empirical ◽  
The Impact

Based on the large amounts of field impact tests with different projectile nosed shapes, the abilities of the existing classical empirical and semi-empirical impact formulae in predicting the local damage of normal and high strength concrete targets (NSCT & HSCT) under the strike of rigid projectile were evaluated. It finds that, firstly, for the penetration depth, the Forrestal and Chen & Li semi-empirical formulae, BRL and Whiffen empirical formulae are advised for the NSCT under the impact of ogive nosed projectile; and Chen & Li semi-empirical formula and ACE empirical formulae are advised for the NSCT under the impact of special nosed projectile; the dimensionless penetration depth of NSCT increases linearly with the non-dimensional impact factor. Secondly, for the penetration depth, Chen & Li semi-empirical formula is advised for the HSCT under the mid-to-high speed impact, and the existing formulae are not applicable while the speed of the projectile was relatively low. Thirdly, for the perforation mode of the target, the BRL and Chang empirical formulae are advised for the NSCT, and the Chen semi-empirical formula, ACE and BRL empirical formulae are advised for the HSCT.

High and Low Speed Impact Characteristics of Nanocomposites

2015 ◽  
Vol 1105 ◽  
pp. 62-66 ◽  
Author(s):  
Saud Aldajah ◽  
Yousef Haik ◽  
Kamal Moustafa ◽  
Ammar Alomari
Keyword(s):  
High Speed ◽  
Impact Resistance ◽  
Absorption Capacity ◽  
Impact Testing ◽  
Energy Absorption Capacity ◽  
Low Speed ◽  
High Speed Impact ◽  
Bulletproof Vest ◽  
Impact Characteristics ◽  
The Impact

Nanocomposites attracted the attention of scientists due to their superior mechanical, thermal, chemical and electrical properties. This research studied the impact of adding carbon nanotubes (CNTs) to the woven Kevlar laminated composites on the high and low speed impact characteristics. Different percentages of CNTs were added to the woven Kevlar-Vinylester composite materials. An in-house developed drop weight testing apparatus was utilized for the low speed impact testing. Two different concentrations of the CNTs were added to a 15-layer woven Kevlar laminates, 0.32 wt% and 0.8 wt%. The results showed that: The 0.32 wt % CNT sample enhanced the interlaminar strength of the composite without enhancing the energy absorption capacity whereas, the 0.8 wt % CNT sample did not improve the impact resistance of the Kevlar composite.For the high speed impact tests, a bulletproof vest was prepared using woven Kevlar, resin, and CNTs at 1.5 w% percentage. The ballistic shooting was carried out by a professional shooter using a 30 caliber and 9 mm bullets for the tests. The CNT bulletproof sample bounced back the 30 caliber copper alloy bullet with no penetration.

scholarly journals Experimental Evaluation of Erosion of Gunmetal under Asymmetrical Shaped Sand Particle

2015 ◽  
Vol 2015 ◽  
pp. 1-31 ◽  
Author(s):  
Mohammad Asaduzzaman Chowdhury ◽  
Uttam Kumar Debnath ◽  
Dewan Muhammad Nuruzzaman ◽  
Md. Monirul Islam
Keyword(s):  
Impact Velocity ◽  
Wear Behavior ◽  
Maximum Level ◽  
Impact Angle ◽  
Operating Conditions ◽  
Silica Sand ◽  
Sand Particle ◽  
Damage Propagation ◽  
Erosion Efficiency ◽  
The Impact

The erosion characteristics of gunmetal have been evaluated practically at different operating conditions. Asymmetrical silica sand (SiO2) is taken into account as erodent within range of 300–600 μm. The impact velocity within 30–50 m/sec, impact angle 15–900, and stand off distance 15–25 mm are inspected as other relevant operating test conditions. The maximum level of erosion is obtained at impact angle 15° which indicates the ductile manner of the tested gunmetal. The higher the impact velocity, the higher the erosion rate as almost linear fashion is observed. Mass loss of gunmetal reduces with the increase of stand-off distance. A dimensional analysis, erosion efficiency (η), and relationship between friction and erosion indicate the prominent correlation. The test results are designated using Taguchi’s and ANOVA concept.S/Nratio indicates that there are 1.72% deviations that are estimated between predicted and experimental results. To elaborately analyze the results, ANN and GMDH methods are mentioned. After erosion process of tested composite, the damage propagation on surfaces is examined using SEM for the confirmation of possible nature of wear behavior. The elemental composition of eroded test samples at varying percentage of gunmetal is analyzed by EDX analysis.

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