Dynamic Analysis of Thin Glass Under Ball Drop Impact With New Metrics

2013 ◽  
Author(s):  
Liang Xue ◽  
Claire R. Coble ◽  
Hohyung Lee ◽  
Da Yu ◽  
Satish Chaparala ◽  
...  
Keyword(s):  
High Speed ◽  
Impact Testing ◽  
Image Correlation ◽  
Thin Glass ◽  
Fea Model ◽  
Wear And Tear ◽  
Local Measurements ◽  
Drop Impacts ◽  
Global And Local ◽  
The Impact

Response of brittle plate to impact loads has been the subject of many research studies [1–7]. Specifically, glass presents a wide variety of applications in daily life, and helps to protect the displays of smartphones, tablets, PCs, and TVs from everyday wear and tear. Therefore, the necessity of glass to resist scratches, drop impacts, and bumps from everyday use leads to the importance of investigation of the glass response under dynamic impact loading. The ball drop test has been applied in the past, specifying an energy threshold as a prediction metric. Use of energy as the key parameter in impact testing is limited, since it does not account for the time spent in contact during the impact event. This study attempts to establish a reliable metric for impact testing based on a momentum change threshold. The deformation and the strain of the glass will be obtained by the Digital Image Correlation (DIC) system, while the rebound velocity will be measured with the high speed cameras. The global and local measurements are conducted to verify the accuracy of the experimental results. Finally, the FEA model is developed using ANSYS/LS-DYNA to provide a comprehensive understanding of the dynamic response of the glass. Excellent correlation in deflection is obtained between the measurements and predictions.

An Experimental and Numerical Study of the Behavior of the Thin Glass Edge Under Ball Drop Impact

2013 ◽  
Author(s):  
Liang Xue ◽  
Dapeng Liu ◽  
Hohyung Lee ◽  
Da Yu ◽  
Satish Chaparala ◽  
...  
Keyword(s):  
High Speed ◽  
Numerical Study ◽  
Image Correlation ◽  
Cover Glass ◽  
Thin Glass ◽  
Impact Process ◽  
Fea Model ◽  
Plane Displacement ◽  
The Impact ◽  
Glass Edge

Glass is widely used as cover glass to protect the smartphones, tablets, PCs, and TVs from everyday wear and tear nowadays. There has been an increasing effort to understand the global behavior of glass substrate under impact, but the behavior of the edge for the thin glass has rarely been touched. In this study, the dynamic response of the glass edge when impacted with 1.75-inch steel ball from different heights (different potential energy) and different angles is studied. High-speed camera is applied for the direct visualization of the whole impact process. The Digital Image Correlation (DIC) method enables to obtain displacements (in-plane displacement and out-of-plane displacement) of the glass during the impact process. The failure mode for the edge impact is found to be predominantly buckling. The tape used in this study decreases wave propagation from the impact location. In addition, the FEA model of edge impact test is developed in ANSYS/LS-DYNA™.

scholarly journals Full-Field Operational Modal Analysis of an Aircraft Composite Panel from the Dynamic Response in Multi-Impact Test

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1602
Author(s):  
Ángel Molina-Viedma ◽  
Elías López-Alba ◽  
Luis Felipe-Sesé ◽  
Francisco Díaz
Keyword(s):  
Modal Analysis ◽  
Energy Absorption ◽  
High Speed ◽  
Operational Modal Analysis ◽  
Modal Identification ◽  
Image Correlation ◽  
Composite Panel ◽  
Impact Excitation ◽  
Full Field ◽  
The Impact

Experimental characterization and validation of skin components in aircraft entails multiple evaluations (structural, aerodynamic, acoustic, etc.) and expensive campaigns. They require different rigs and equipment to perform the necessary tests. Two of the main dynamic characterizations include the energy absorption under impact forcing and the identification of modal parameters through the vibration response under any broadband excitation, which also includes impacts. This work exploits the response of a stiffened aircraft composite panel submitted to a multi-impact excitation, which is intended for impact and energy absorption analysis. Based on the high stiffness of composite materials, the study worked under the assumption that the global response to the multi-impact excitation is linear with small strains, neglecting the nonlinear behavior produced by local damage generation. Then, modal identification could be performed. The vibration after the impact was measured by high-speed 3D digital image correlation and employed for full-field operational modal analysis. Multiple modes were characterized in a wide spectrum, exploiting the advantages of the full-field noninvasive techniques. These results described a consistent modal behavior of the panel along with good indicators of mode separation given by the auto modal assurance criterion (Auto-MAC). Hence, it illustrates the possibility of performing these dynamic characterizations in a single test, offering additional information while reducing time and investment during the validation of these structures.

scholarly journals Experimental investigation of the impact response of novel steelbiocomposite hybrid materials

2018 ◽  
Vol 183 ◽  
pp. 02040
Author(s):  
KarthikRam Ramakrishnan ◽  
Mikko Hokka ◽  
Essi Sarlin ◽  
Mikko Kanerva ◽  
Reijo Kouhia ◽  
...  
Keyword(s):  
High Speed ◽  
Structural Integrity ◽  
Metal Layer ◽  
Rear Surface ◽  
Impact Resistance ◽  
Natural Fibre ◽  
Image Correlation ◽  
Impact Response ◽  
High Speed Camera ◽  
The Impact

Recent developments in the production of technical flax fabrics allow the use of sustainable natural fibres to replace synthetic fibres in the manufacture of structural composite parts. Natural fibre reinforced biocomposites have been proven to satisfy design and structural integrity requirements but impact strength has been identified as one of their limitations. In this paper, hybridisation of the biocomposite with a metal layer has been investigated as a potential method to improve the impact resistance of natural fibre composites. The impact response of biocomposites made of flax-epoxy is investigated experimentally using a high velocity particle impactor. A high-speed camera setup was used to observe the rear surface of the plates during impact. Digital Image Correlation (DIC) of the high speed camera images was used for full-field strain measurement and to study the initiation and propagation of damage during the impact. The different modes of damage in the hybrid laminate were identified by postimpact analysis of the section of the damaged composite plate using optical microscopy. The study shows the difference in impact response for different material combinations and configurations. The hybrid construction was shown to improve the impact resistance of the flax composite.

A Novel Method for Optical High Spatiotemporal Strain Analysis for Transcatheter Aortic Valves In Vitro

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Simon Heide-Jørgensen ◽  
Sellaswasmy Kumaran Krishna ◽  
Jonas Taborsky ◽  
Tommy Bechsgaard ◽  
Rachid Zegdi ◽  
...  
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Strain Analysis ◽  
Image Correlation ◽  
Deformation Analysis ◽  
Flow Loop ◽  
Transcatheter Aortic Valve ◽  
Wear And Tear ◽  
Valve Implantation

The transcatheter aortic valve implantation (TAVI) valve is a bioprosthetic valve within a metal stent frame. Like traditional surgical bioprosthetic valves, the TAVI valve leaflet tissue is expected to calcify and degrade over time. However, clinical studies of TAVI valve longevity are still limited. In order to indirectly assess the longevity of TAVI valves, an estimate of the mechanical wear and tear in terms of valvular deformation and strain of the leaflets under various conditions is warranted. The aim of this study was, therefore, to develop a platform for noncontact TAVI valve deformation analysis with both high temporal and spatial resolutions based on stereophotogrammetry and digital image correlation (DIC). A left-heart pulsatile in vitro flow loop system for mounting of TAVI valves was designed. The system enabled high-resolution imaging of all three TAVI valve leaflets simultaneously for up to 2000 frames per second through two high-speed cameras allowing three-dimensional analyses. A coating technique for applying a stochastic pattern on the leaflets of the TAVI valve was developed. The technique allowed a pattern recognition software to apply frame-by-frame cross correlation based deformation measurements from which the leaflet motions and the strain fields were derived. The spatiotemporal development of a very detailed strain field was obtained with a 0.5 ms time resolution and a spatial resolution of 72 μm/pixel. Hence, a platform offering a new and enhanced supplementary experimental evaluation of tissue valves during various conditions in vitro is presented.

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.

Measurement of Transient Dynamic Response of Circuit Boards of a Handheld Device During Drop Using 3D Digital Image Correlation

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
S. B. Park ◽  
Chirag Shah ◽  
Jae B. Kwak ◽  
Changsoo Jang ◽  
Soonwan Chung ◽  
...  
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
High Speed ◽  
Image Correlation ◽  
Impact Response ◽  
Experimental Methodology ◽  
Full Field ◽  
Handheld Device ◽  
3D Digital Image Correlation ◽  
The Impact

In this work, a new experimental methodology for analyzing the drop impact response is assessed using a pair of high-speed digital cameras and 3D digital image correlation software. Two different test boards are subjected to Joint Electron Device Engineering Council (JEDEC) standard free-fall impact conditions of half-sine pulse of 1500 G in magnitude and 0.5 ms in duration. The drop is monitored using a pair of synchronized high-speed cameras at a rate of up to 15,000 frames per second. The acquired images are subsequently analyzed to give full-field dynamic deformation, shape, and strain over the entire board during and after impact. To validate this new methodology for analyzing the impact response, the in-plane strain as well as the out-of-plane acceleration at selected locations were measured simultaneously during the drop using strain gauge and accelerometers and were compared with those obtained using high-speed cameras and 3D digital image correlation presented in this paper. Comparison reveals excellent correlation of the transient behavior of the board during impact and confirms the feasibility of using the full-field measurement technique used in this study.

The Influence of Facet Size on the Accuracy of Modal Parameters Determined by Digital Image Correlation Technique

2014 ◽  
Vol 611 ◽  
pp. 496-500 ◽  
Author(s):  
Róbert Huňady ◽  
Martin Hagara ◽  
František Šimčák
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
High Speed ◽  
Image Correlation ◽  
Modal Parameters ◽  
Correlation Technique ◽  
Correlation System ◽  
Correlation Process ◽  
The Impact ◽  
Facet Size

The paper deals with measurements of modal parameters using high-speed digital image correlation and assesses how the size of image elements (facets) influences the accuracy of modal parameters of the analyzed structure. The facet size is an important parameter that significantly affects the correlation process and its results. In the paper the experimental modal analysis of steel circular plate that has been excited by the impact hammer is described. Correlation system Q-450 Dantec Dynamics was used to measure the responses of the analyzed structure.

The Study of Blanking Frequency Effect on the Acceleration Performance of Impact Testing Machine Rotor

2014 ◽  
Vol 543-547 ◽  
pp. 150-153
Author(s):  
Yuan Bo Cai ◽  
Fang Zhao ◽  
Shi Jian Li ◽  
Na Zhao
Keyword(s):  
High Speed ◽  
Testing Machine ◽  
Impact Testing ◽  
Frequency Effect ◽  
Rotating Speed ◽  
Impact Testing Machine ◽  
Movement Characteristics ◽  
The Impact ◽  
Feed Inlet

This paper designed an impact testing machine to observe the movement characteristics of particles. We simulated the rotor with different blanking frequency and different rotating speed by EDEM to explore the acceleration of the rotor. Through simulation, blanking frequency could have an impact on the rotor acceleration of testing machine, and the greater Blanking frequency was, the more obvious hanging material phenomenon was. Increasing the diameter of feed inlet could ease the phenomenon of hanging material, but would decrease particles speed. Therefore, we should not only avoid the phenomenon of hanging material, but also make the particles get high speed when designing the impact testing machine.

Evaluation of Sliding Behavior of Simple Structures for Oblique Collision

2014 ◽  
Vol 566 ◽  
pp. 611-616
Author(s):  
Takeru Watanabe ◽  
Naoya Nishimura ◽  
Hiroka Watanabe ◽  
Syouta Nakadate ◽  
Katsuhiko Murase
Keyword(s):  
Contact Surface ◽  
High Speed ◽  
Simple Structure ◽  
Impact Test ◽  
Testing Machine ◽  
Impact Testing ◽  
Oblique Collision ◽  
Before And After ◽  
Collapse Behavior ◽  
The Impact

When a simple structure collides with inclined barrier, behavior and deformation of the structure after impact are different in the case in which the structure slides on a contact surface or the case in which it does not slide. In order to investigate the structural collapse behavior for oblique collided structure, therefore, it is important to clarify the sliding behavior of the structure on the contact surface. The sliding behavior of the structure during collision was estimated according to theoretically obtained the equation considering the equilibrium of change in the momentum and the impulse before and after the collision. For evaluating the sliding behavior of the simple structure, the impact test by the drop type impact testing machine was carried out to collide with inclined barrier. In the impact test, the circular plate of 60 mm diameter and 10 mm thickness was used as the simple structure, and impacted with various collision velocities (range from 2 to 6 m/s). The sliding behavior of the simple structure at the collided surface was observed by high speed camera, and evaluated by the image analysis. The theoretical result was compared to evaluate with experimental results.

scholarly journals Visual Methods to Assess Strain Fields in Armour Materials Subjected to Dynamic Deformation—A Review

2020 ◽  
Vol 10 (8) ◽  
pp. 2644
Author(s):  
Chris L. Ellis ◽  
Paul Hazell
Keyword(s):  
Plastic Deformation ◽  
High Speed ◽  
Large Strain ◽  
Speckle Pattern ◽  
Three Dimensional ◽  
Impact Testing ◽  
Image Correlation ◽  
Visual Methods ◽  
High Speed Impact ◽  
Impact Events

When impacted by a projectile, ballistic protection undergoes very large strain rates over very short periods of time. During these impact events, materials will undergo a very short region of elastic deformation, before undergoing significant plastic deformation. Due to the high levels of plastic deformation the samples undergo, strain gauges and other embedded sensors are often ineffective or become damaged before useful data can be obtained. Three-dimensional digital image correlation (3D DIC) is a non-invasive measurement method that uses two high-speed cameras, offset from each other by 15–45° to observe a speckle pattern on the sample material. As the material, and by extension the speckle pattern, deforms, the images taken throughout the deformation can be compared in sequence, to determine the motion and deformation of the sample. Recent advances in camera technology have allowed for frame rates in the hundreds of thousands of frames per-second, allowing for the measurement of very high-strain rate impact events. This paper will describe the premise of 3D DIC and provide a review of the current applications and research into high-speed impact testing using 3D DIC.

Sign in / Sign up

Export Citation Format

Share Document