Numerical Analysis of Impact Behavior of Rotary Centrifuge Guarded Body

2015 ◽  
pp. 167-176
Author(s):  
Weizhou Zhong ◽  
Xicheng Huang ◽  
Chengang Luo ◽  
Gang Chen ◽  
Zhifang Deng
Keyword(s):  
Numerical Analysis ◽  
Impact Behavior

Impact Behavior of Rocking Bridge Piers

2002 ◽  
Author(s):  
Chin-Tung Cheng ◽  
Ming-Hsiang Shih
Keyword(s):  
Numerical Analysis ◽  
Kinetic Energy ◽  
Aspect Ratio ◽  
Cross Section ◽  
Bridge Piers ◽  
Impact Behavior ◽  
Restoring Forces ◽  
Numerical Process ◽  
Dissipation Characteristic ◽  
Rocking Behavior

This research aims to investigate the energy dissipation characteristic and impact behavior of rocking piers under free vibration. Research parameters include rocking interfaces (stiff or flexible), geometry of the column cross-section (circular or rectangular), aspect ratio of the columns, anchorage of prestressing tendons and scale effect. To validate the proposed theory, five columns were constructed and will be tested. A numerical process was proposed to simulate the rocking behavior of columns. Numerical analysis revealed that aspect ratio remarkably affects the rocking behavior, however, size effect and shape of cross section had no significant influence on the rocking behavior. Contrary to the instinct, anchored columns may have less damping due to the higher restoring forces that leads to larger acceleration and slower degradation in kinetic energy.

Influence of the specimen thickness on low velocity impact behavior of composites

2012 ◽  
Vol 32 (1) ◽  
Author(s):  
Ana M. Amaro ◽  
Paulo Nobre Balbis Reis ◽  
Marcelo de Moura ◽  
Jaime B. Santos
Keyword(s):  
Numerical Analysis ◽  
Physical Phenomenon ◽  
Plate Thickness ◽  
Damage Model ◽  
Low Velocity Impact ◽  
Impact Behavior ◽  
Specimen Thickness ◽  
Low Velocity ◽  
Internal Damage ◽  
Velocity Impact

Abstract In this work, the influence of specimen thickness on low velocity impact behavior of carbon-epoxy composite laminates is studied. Plates with different thicknesses were tested under low velocity impact using a hemispherical impactor. The internal damage was mainly constituted by delaminations which were evaluated through the inspection of the impacted plates by the ultrasonic C-scan technique. It was observed that delaminations increase with plate thickness. In order to better understand the physical phenomenon explaining this result, a progressive damage model was used to simulate composites behavior under low velocity impact. In this context, a three-dimensional numerical analysis considering interface finite elements, including a cohesive mixed-mode damage model, which allows simulating delaminations onset and growth between layers, was performed. Good agreement was obtained between experimental and numerical analysis, which validated the proposed procedure. In addition, the proposed numerical methodology allowed identification of physical phenomena related to the influence of plate thickness on delamination size.

scholarly journals New Equivalent Linear Impact Model for Simulation of Seismic Isolated Structure Pounding against Moat Wall

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Yang Liu ◽  
Wen-Guang Liu ◽  
Xin Wang ◽  
Wen-Fu He ◽  
Qiao-Rong Yang
Keyword(s):  
Numerical Analysis ◽  
Structural Response ◽  
Impact Response ◽  
Impact Behavior ◽  
Impact Model ◽  
Near Fault ◽  
Equivalent Linear ◽  
Proposed Model ◽  
Voigt Model ◽  
Near Fault Earthquakes

Base-isolated buildings subjected to extreme earthquakes or near-fault pulse-like earthquakes can exceed their design gap distance and impact against the surrounding moat wall. Based on equating energy dissipation and maximum collision compression deformation of isolated structure with the Hertz-damp model and Kevin-Voigt model in the process of collision, an equivalent linear impact model (ELIM) is proposed to better predict impact response of seismic isolated structure. The formula of the equivalent linear stiffness of ELIM is theoretically derived. The effectiveness of ELIM is verified by comparing the results of numerical analyses with the results of pounding experiments. Four near-fault earthquakes are selected to validate rationality and accuracy of the proposed model using numerical analysis. The results indicate that the proposed linear model can nearly capture impact behavior of isolated structure in simulating the pounding-involved structural response.

In-Plane Low Velocity Impact Behavior of GFRP Laminate

2020 ◽  
Vol 978 ◽  
pp. 257-263
Author(s):  
Mahesh ◽  
Kalyan Kumar Singh
Keyword(s):  
Numerical Analysis ◽  
Boundary Conditions ◽  
Impact Loading ◽  
Weight Ratio ◽  
Low Velocity Impact ◽  
Impact Behavior ◽  
Low Velocity ◽  
Velocity Impact ◽  
Material Tailoring ◽  
Out Of Plane

FRP laminates are used in several industries such as automobile, aircraft’s, spacecraft’s, defense and etc.., where high strength-to-weight ratio is the primary criteria. FRP laminates offer high design and material tailoring properties but are highly susceptible to delamination and debonding under out-of-plane low velocity impact which induces barely visible impact damage (BVID) inside the structures. A lot of research investigation is going on related to damage resistance behavior of FRP laminates under out-of-plane impact loading. But very less concentration is paid to the FRP laminates behavior under in-plane low impact loading. In this numerical analysis in-plane low velocity impact loading is carried out on a bidirectional plain woven glass fiber reinforced epoxy laminate (GFRP) using LS-DYNA. A hemispherical impactor of mass 5kg and diameter of 10mm is impacted at 0.5, 1.0 and 1.5m/sec velocity on [(00/900)/(+450/-450)/(+450/-450)/(00/900)]S layup design. Two boundary conditions complete edge and corner constraining boundary conditions are considered for numerical analysis. Force vs. time, energy vs. time, displacement vs. time plots are used to evaluate the analysis.

Residual Stress Characterization From Numerical Analysis of the Multi-Particle Impact Behavior in Cold Spray

2017 ◽  
Author(s):  
Kando Hamiyanze Moonga ◽  
Tien-Chien Jen
Keyword(s):  
Residual Stress ◽  
Numerical Analysis ◽  
Compressive Stress ◽  
Cold Spray ◽  
High Speed ◽  
Compressive Residual Stress ◽  
Impact Behavior ◽  
Particle Impact ◽  
Cold Spray Process ◽  
Spray Process

In cold spray, bonding forms between a substrate and the particles and between particles through impact deformation at high strain rates. A prominent feature of the cold spray process is the compressive residual stress that arises during the deposition process. Compressive residual stress on the surface can be beneficial for fatigue resistance. As a post processing technique several applications require surface treatment processes that produce this state of stress on component surfaces such as shot peening, laser shock peening, ultrasonic impact treatment, low plasticity burnishing, etc. In all of these methods, the compressive stress is produced through plastic deformation of the surface region. In a similar manner, the cold spray process induces compressive stress by high speed impact of the sprayed particles on the surface, causing a peening effect. The effects of these variations in the properties of the coatings are rarely reported. Moreover, there are some applications which require minimal residual stresses in the components such as in optics. In this study, we have investigated the residual stress using numerical analysis of the multi-particle impact behavior in cold spray.

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