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 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.

Effects of the DART (NASA) mission collision on the structure and spin state of the secondary of the Near-Earth asteroid (65803) Didymos binary system.

2020 ◽  
Author(s):  
Paula Benavidez ◽  
Adriano Campo Bagatin ◽  
Manuel Perez-Molina ◽  
Derek C. Richardson ◽  
Antonio Santana-Ros ◽  
...  
Keyword(s):  
Binary System ◽  
Kinetic Energy ◽  
Orbital Plane ◽  
Impact Angle ◽  
Numerical Code ◽  
Asteroid Impact ◽  
Earth Asteroid ◽  
Post Impact ◽  
Impact Kinetic Energy ◽  
The Impact

<p>AIDA (Asteroid Impact & Deflection Assessment) is an international collaboration between NASA and ESA which involves both DART (Double Asteroid Redirection Test, NASA) and Hera (ESA) missions. The target is an asteroid of approximately 160 m in size, namely the secondary of the binary Near-Earth Asteroid (65803) Didymos. Little is known about the shape of the satellite, with a moderately elongated shape (b/a<1.2) compatible with available ground-based estimations. In this work we investigate the possible reaction of the target to the DART collision to be performed in 2022, under the assumption that it is a gravitational aggregate produced in the formation of the binary system. The very structure of the target is unknown, therefore we model it by (1) mono- and multi-dispersed distributions of spherical basic elements and by (2) considering irregular components. We perform numerical simulations of the collision event by using a discrete-element N-body numerical code (PKDGRAV-SSDEM). We do not perform simulations of the shattering phase, we instead concentrate on the effect of the collision on the target, after the shattering phase implying material damage (melting, vaporization, heating and deformation), is over. Therefore, our synthetic projectile carries the same nominal momentum as the DART mission does, but it delivers to the target only the kinetic energy expected to survive once the shattering (non-elastic) phase has dissipated most of the impact kinetic energy. We account for different centre- and off-centre- possible impact geometry compatible with DART nominal impact angle with respect to the target orbital plane.</p> <p>Here we report on results obtained so far on the effects of the DART impact on the structure of the Didymos satellite, including changes in its spin period and direction of the direction of the spin axis, as well as change of shape.</p> <p>Moreover, we look at the velocity field of surface particles to infer if any motion is expected away from the impact point and regolith particles can be ejected from locations far from it.</p> <p>Such predictions may be of interest in the study of the post-impact dynamics of the system –that will be determined by the Hera mission measurements. This, in turn will help in the interpretation of the results of the outcome of the DART impact mission, including the determination of the momentum multiplication (beta) factor.</p> <p> </p>

scholarly journals Impact and Ricochet of a High Speed Projectile from a Plate

2021 ◽  
Vol 71 (6) ◽  
pp. 737-747
Author(s):  
Hussein Bassindowa ◽  
Bakhtier Farouk ◽  
Steven B. Segletes
Keyword(s):  
Titanium Alloy ◽  
High Speed ◽  
Computational Study ◽  
Incident Angle ◽  
Finite Thickness ◽  
Impact Angle ◽  
Projectile Velocity ◽  
Alloy Plate ◽  
Impact Angles ◽  
The Impact

A computational study of a projectile (either 2024 aluminum or TiAl6V4 titanium alloy) impacting a plate (either titanium alloy or aluminum) is presented in this paper. Projectile velocity (ranging from 250 m/s to 1500 m/s) with varying impact angles are considered. The presence of ricochet (if any) is identified over the ranges of the projectile velocity and impact angle considered. For the cases where ricochet is identified, the ricochet angle and velocity are predicted as functions of the incident angle and the incident velocity. The numerical results are compared with an analytical solution of the ricochet problem. The analytical solutions are from a model developed to predict the ballistic ricochet of a projectile (projectile) penetrator. The dynamics and the deformation of an aluminum (or a titanium alloy) projectile impacting on a finite thickness titanium alloy (or aluminum) plate are simulated. The current work is interesting in that it looks in the field of ballistics of different material combinations than are traditionally studied. The present simulations based on detailed material models for the aluminum and the titanium alloy and the impact physics modelling features in the LS-DYNA code provide interesting details regarding the projectile/plate deformations and post-impact projectile shape and geometry. The present results indicate that for no cases (for specified incoming velocities and impact angles considered) can an aluminum projectile penetrate a titanium alloy plate. The ricochet ‘mode predictions ‘obtained from the present simulations agree well with the ricochet ‘mode predictions’ given in an analytical model.

scholarly journals 3D Modelling of the Scattering of the Fundamental Anti-Symmetric Lamb Mode (A0) Propagating within a Point-Impacted Transverse-Isotropic Composite Plate

2021 ◽  
Vol 11 (16) ◽  
pp. 7276
Author(s):  
Dilbag Singh ◽  
Mourad Bentahar ◽  
Charfeddine Mechri ◽  
Rachid El Guerjouma
Keyword(s):  
Composite Plate ◽  
Impact Damage ◽  
Elastic Stiffness ◽  
Wave Mode ◽  
Guided Wave ◽  
Domain Model ◽  
Isotropic Composite ◽  
Damaged Zone ◽  
The Impact ◽  
Lamb Mode

The present paper deals with an effort to model impact damage in 3D-FE simulation. In this work, we studied the scattering behavior of an incident A0 guided wave mode propagating towards an impacted damaged zone created within a quasi-isotropic composite plate. Besides, barely visible impact damage of the desired energy was created and imaged using ultrasonic bulk waves in order to measure the size of the damage. The 3D-FE frequency domain model is then used to simulate the scattering of an incident guided wave at a frequency below an A1 cut-off with a wavelength comparable to the size of the damaged zone. The damage inside the plate is modeled as a conical-shaped geometry with decayed elastic stiffness properties. The model was first validated by comparing the directivity of the scattered fields for the A0 Lamb mode predicted numerically with the experimental measurements. The modeling of the impact zone with conical-shape geometry showed that the scattering directivity of the displacement field depends significantly on the size (depth and width) of the conical damage created during the point-impact of the composite with potential applications allowing the determination of the geometric characteristics of the impacted areas.

scholarly journals Particle Impact and Breakup in Aircraft Measurement

2009 ◽  
Vol 26 (5) ◽  
pp. 972-983 ◽  
Author(s):  
German Vidaurre ◽  
John Hallett
Keyword(s):  
Kinetic Energy ◽  
Surface Energy ◽  
Cloud Particle ◽  
Aircraft Measurement ◽  
University Of North Dakota ◽  
Particle Properties ◽  
Imaging Probes ◽  
Impact Kinetic Energy ◽  
The Impact ◽  
Particle Approach

Abstract Measurements of cloud particle properties from aircraft by optical and impact techniques are subject to artifacts following particle breakup prior to detection. The impact kinetic energy to surface energy ratio (ℒ) provides a breakup criterion at ℒ ≥ 7 for water and ice with major fragmentation for ℒ > 100. This applies to optical imaging probes for particle concentration, size, and projected area spectra measurement. Uncertainty arises should impacting particles shatter and disperse, defeating the intent of the original measurements. Particle shatter is demonstrated in Formvar replicas (University of North Dakota Citation) and video records of particle approach and impact on the Cloudscope (NCAR C-130, NASA DC-8) at airspeeds of 130 and 200 m s−1. Sufficient impact kinetic energy results in drop splash and ice shatter, with conversion to surface energy and ultimately thermal energy through viscous dissipation and ice defect production occurring down to the molecular scale. The problem is minimized in design by reducing the regions responsible for particle breakup to a minimum and locating sensors in regions inaccessible to shatter fragments.

Research of Performance about Ceramic Coating on Aluminum Bumper to Resist Hypervelocity Impact

2013 ◽  
Vol 577-578 ◽  
pp. 629-632
Author(s):  
Gong Shun Guan ◽  
Qiang Bi ◽  
Yu Zhang
Keyword(s):  
Kinetic Energy ◽  
Optimum Design ◽  
Critical Thickness ◽  
Ceramic Coating ◽  
Impact Angle ◽  
Hypervelocity Impact ◽  
Front Side ◽  
Gas Gun ◽  
Whipple Shield ◽  
The Impact

Shield structure based on ceramic coating on aluminum bumper was designed, and a series of hypervelocity impact tests were practiced with a two-stage light gas gun facility. Impact velocities were varied between1.5km/s and 5.0km/s. The diameter of projectiles were 3.97mm and 6.35mm respectively. The impact angle was 0°. The damage of the ceramic coating on aluminum bumper under hypervelocity impact was studied. It was found that the ceramic coating on aluminum bumper could help enhancing the protection performance of shield to resist hypervelocity impact. The results indicated when the ceramic coating is on the front side of aluminum bumper, it was good for comminuting projectile and weakening the kinetic energy of projectile. For a certain aluminum bumper, existing a critical thickness of ceramic coating in which capability of Whipple shield to resist hypervelocity impact is the best. On this basis, the proposal of the optimum design for ceramic coating on aluminum bumper was made.

INFLUENCE OF THE IMPACT ANGLE OF A SOLID PARTICLE JET ON THE EROSION WEAR OF 38GSA AND HARDOX 500 STEEL

Tribologia ◽  
2017 ◽  
Vol 273 (3) ◽  
pp. 85-90 ◽  
Author(s):  
Bazyli KRUPICZ ◽  
Wojciech TARASIUK ◽  
Jerzy NAPIÓRKOWSKI ◽  
Krzysztof LIGIER
Keyword(s):  
Mechanical Properties ◽  
Kinetic Energy ◽  
Solid Particle ◽  
Quartz Sand ◽  
Impact Angle ◽  
Erosion Wear ◽  
Sand Particles ◽  
Work Of Deformation ◽  
The Impact

The paper investigated the influence of the impact angle of a solid particle jet on the erosion wear of 38GSA and Hardox 500 steel. The basis of the analysis was the assumption of the existence of a correlation between mechanical properties of the material, represented by the work of deformation (P) determined from the stressstrain diagram (U). The impact angle of quartz sand particles (30, 60, and 90 °) was considered through the separation of kinetic energy of particles impacting the eroded surface perpendicularly and tangentially.

Initial response mechanism and local contact stiffness analysis of the floating two-stage buffer collision-prevention system under ship colliding

2021 ◽  
pp. 136943322098610
Author(s):  
Kai Lu ◽  
Xu-Jun Chen ◽  
Zhen Gao ◽  
Liang-Yu Cheng ◽  
Guang-Huai Wu
Keyword(s):  
Kinetic Energy ◽  
Impact Force ◽  
Contact Stiffness ◽  
Impact Angle ◽  
Bridge Pier ◽  
Two Stage ◽  
Collision Prevention ◽  
Prevention System ◽  
The Impact ◽  
Depth Curves

A floating two-stage buffer collision-prevention system (FTBCPS) has been proposed to reduce the impact loads on the bridge pier in this paper. The anti-collision process can be mainly divided into two stages. First, reduce the ship velocity and change the ship initial moving direction with the stretching and fracture of the polyester ropes. Second, consume the ship kinetic energy with the huge damage and deformation of the FTBCPS and the ship. The main feature of the FTBCPS lies in the first stage and most of the ship kinetic energy can be dissipated before the ship directly impacts on the bridge pier. The contact stiffness value between the ship and the FTBCPS can be a significant factor in the first stage and the calculation method of it is the focus of this paper. The contact force, the internal force and the general equation of motion have been given in the first part. The structure model of the ship and the FTBCPS are then established in the ANSYS Workbench. After that, 38 typical load cases of the ship impacting on the FTBCPS are conducted in LS-DYNA. The reduction processes of the ship kinetic energy and the ship velocity in different load cases have been investigated. It can be summarized that the impact angle and the ship initial velocity are the main factors in the energy and velocity dissipation process. Moreover, the local impact force-depth curves have also been studied and the impact angle is found to be the only significant factor on the ship impact process. Next, the impact force-depth curves with different impact angles are fitted and the contact stiffness values are accordingly calculated. Finally, the impact depth range, the validity of the local simulation results and the consistency of the fitted stiffness value are verified respectively, demonstrating that the fitted stiffness values are applicable in the global analysis.

scholarly journals Impact Response and Damage Tolerance of Hybrid Glass/Kevlar-Fibre Epoxy Structural Composites

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2591
Author(s):  
Vasudevan Alagumalai ◽  
Vigneshwaran Shanmugam ◽  
Navin Kumar Balasubramanian ◽  
Yoganandam Krishnamoorthy ◽  
Velmurugan Ganesan ◽  
...  
Keyword(s):  
Composite Laminates ◽  
High Speed ◽  
Fibre Orientation ◽  
Impact Damage ◽  
Charpy Impact ◽  
Compression Moulding ◽  
Post Impact ◽  
Ballistic Test ◽  
Interlaminar Shear ◽  
The Impact

The present study is aimed at investigating the effect of hybridisation on Kevlar/E-Glass based epoxy composite laminate structures. Composites with 4 mm thickness and 16 layers of fibre (14 layers of E-glass centred and 2 outer layers of Kevlar) were fabricated using compression moulding technique. The fibre orientation of the Kevlar layers had 3 variations (0, 45 and 60°), whereas the E-glass fibre layers were maintained at 0° orientation. Tensile, flexural, impact (Charpy and Izod), interlaminar shear strength and ballistic impact tests were conducted. The ballistic test was performed using a gas gun with spherical hard body projectiles at the projectile velocity of 170 m/s. The pre- and post-impact velocities of the projectiles were measured using a high-speed camera. The energy absorbed by the composite laminates was further reported during the ballistic test, and a computerised tomographic scan was used to analyse the impact damage. The composites with 45° fibre orientation of Kevlar fibres showed better tensile strength, flexural strength, Charpy impact strength, and energy absorption. The energy absorbed by the composites with 45° fibre orientation was 58.68 J, which was 14% and 22% higher than the 0° and 60° oriented composites.

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