Comparative Study of the Dynamic Response of Different Materials Subjected to Compressed Gas Blast Loading

2011 ◽  
Author(s):  
Brandon J. Hinz ◽  
Matthew V. Grimm ◽  
Karim H. Muci-Ku¨chler ◽  
Shawn M. Walsh
Keyword(s):  
Dynamic Response ◽  
High Speed ◽  
Mechanical Response ◽  
Blast Loading ◽  
Test Sample ◽  
Blast Waves ◽  
Small Scale ◽  
Acceleration Time Histories ◽  
Compressed Gas ◽  
Brain Tissue Damage

Understanding the dynamic response of materials under blast and impact loading is of interest for both military and civilian applications. In the case of blast loading, the mitigation characteristics of materials employed in personal protective equipment (PPE) is of particular importance. Without adequate protection, exposure of the head to blast waves may result in or contribute to brain tissue damage leading to traumatic brain injury (TBI). The development of simple but representative laboratory experiments that can be used to study the mechanical response of different materials and/or material combinations to blast loading could be very useful for the design of PPE such as helmets. This paper presents a basic experimental setup that can be conveniently used to perform such studies using small scale compressed gas blasts. An open end shock tube is employed to generate the blasts used to load flat plate samples placed in a special rigid holder. Acceleration time histories at selected locations in the sample are used to generate data to compare the dynamic response and blast mitigation effectiveness of different specimens. High speed schlieren video is used to correlate the arrival of the shock wave and air flow that follows with the motion of the test sample.

Comparison of Numerical and Experimental Results of Small Scale Compressed Gas Blast Experiments Involving a Surrogate Head Form

2012 ◽  
Author(s):  
Matthew V. Grimm ◽  
Karim H. Muci-Küchler ◽  
Brandon J. Hinz ◽  
Shawn M. Walsh
Keyword(s):  
Shock Wave ◽  
Mechanical Response ◽  
Pressure Sensors ◽  
Blast Loading ◽  
Ambient Air ◽  
Experimental Results ◽  
Positive Phase ◽  
Small Scale ◽  
Compressed Gas ◽  
Head Form

Exposure to a shock wave from an explosive blast can result in injury to the human body even if external signs of trauma are not present. Gaining a better understanding of the mechanisms contributing to those injuries can result in the design of better personal protective equipment (PPE). Compressed gas blast experiments can be conveniently used to explore the mechanical response of PPE systems and instrumented surrogate head forms to blast loading scenarios in a laboratory environment. Likewise, numerical simulations can be used to study relevant field variables related to the compressed gas blast and its effects on the target. In this regard, experimental data is needed to validate simulation results. This paper presents an experiment that uses a small scale compressed gas blast generator to explore the pressure distribution around a surrogate head form due to blast loading. The compressed gas blast generator is an open-end shock tube which creates a shock wave when the diaphragm that separates the high pressure and low pressure (ambient air) regions ruptures. The overpressures on selected locations of the surrogate head form were measured with piezoelectric pressure sensors and the data was processed to obtain positive phase durations and positive phase impulses. The surrogate head form was positioned off-axis from the exit of the compressed gas blast generator to preclude the discharge flow from affecting the overpressure measurements. A three-dimensional Coupled Eulerian-Lagrangian (CEL) model of the experiment described above was prepared in Abaqus/Explicit. Selected numerical and experimental results were compared and there was good agreement between them.

The Effect of Strain Rate on the Material Characteristics of Nickel-Based Superalloy Inconel 718

2007 ◽  
Vol 340-341 ◽  
pp. 283-288 ◽  
Author(s):  
Jung Han Song ◽  
Hoon Huh
Keyword(s):  
Dynamic Response ◽  
High Strain Rate ◽  
Strain Rate ◽  
Turbine Blade ◽  
Inconel 718 ◽  
High Speed ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Experimental Results ◽  
Stress Wave Propagation

The dynamic response of the turbine blade materials is indispensable for analysis of erosions of turbine blades as a result of impulsive loading associated with gas flow. This paper is concerned with the dynamic material properties of the Inconel 718 alloy which is widely used in the high speed turbine blade. The dynamic response at the corresponding level of the strain rate should be acquired with an adequate experimental technique and apparatus due to the inertia effect and the stress wave propagation. In this paper, the dynamic response of the Inconel 718 at the intermediate strain rate ranged from 1/s to 400/s is obtained from the high speed tensile test and that at the high strain rate above 1000/s is obtained from the split Hopkinson pressure bar test. The effects of the strain rate on the dynamic flow stress, the strain rate sensitivity and the failure elongation are evaluated with the experimental results. Experimental results from both the quasi-static and the high strain rate up to 3000/s are interpolated in order to construct the constitutive relation that should be applied to simulate the dynamic behavior of the turbine blade made of the Inconel 718.

scholarly journals Fully Automated Cultivation of Adipose-Derived Stem Cells in the StemCellDiscovery—A Robotic Laboratory for Small-Scale, High-Throughput Cell Production Including Deep Learning-Based Confluence Estimation

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 575
Author(s):  
Jelena Ochs ◽  
Ferdinand Biermann ◽  
Tobias Piotrowski ◽  
Frederik Erkens ◽  
Bastian Nießing ◽  
...  
Keyword(s):  
Stem Cells ◽  
Deep Learning ◽  
High Throughput ◽  
High Speed ◽  
New Technologies ◽  
Human Mesenchymal Stem Cells ◽  
Simulation Software ◽  
System Capacity ◽  
Small Scale ◽  
Production Environment

Laboratory automation is a key driver in biotechnology and an enabler for powerful new technologies and applications. In particular, in the field of personalized therapies, automation in research and production is a prerequisite for achieving cost efficiency and broad availability of tailored treatments. For this reason, we present the StemCellDiscovery, a fully automated robotic laboratory for the cultivation of human mesenchymal stem cells (hMSCs) in small scale and in parallel. While the system can handle different kinds of adherent cells, here, we focus on the cultivation of adipose-derived hMSCs. The StemCellDiscovery provides an in-line visual quality control for automated confluence estimation, which is realized by combining high-speed microscopy with deep learning-based image processing. We demonstrate the feasibility of the algorithm to detect hMSCs in culture at different densities and calculate confluences based on the resulting image. Furthermore, we show that the StemCellDiscovery is capable of expanding adipose-derived hMSCs in a fully automated manner using the confluence estimation algorithm. In order to estimate the system capacity under high-throughput conditions, we modeled the production environment in a simulation software. The simulations of the production process indicate that the robotic laboratory is capable of handling more than 95 cell culture plates per day.

scholarly journals Nonlinear magneto-thermo-elastic vibration of mass sensor armchair carbon nanotube resting on an elastic substrate

2020 ◽  
Vol 7 (1) ◽  
pp. 153-165
Author(s):  
Rajendran Selvamani ◽  
M. Mahaveer Sree Jayan ◽  
Rossana Dimitri ◽  
Francesco Tornabene ◽  
Farzad Ebrahimi
Keyword(s):  
Carbon Nanotube ◽  
Mechanical Response ◽  
Scale Effects ◽  
Nonlocal Elasticity Theory ◽  
Wave Dispersion ◽  
Elastic Vibration ◽  
Ultrasonic Waves ◽  
Small Scale ◽  
Dimensionless Frequency ◽  
Mass Sensors

AbstractThe present paper aims at studying the nonlinear ultrasonic waves in a magneto-thermo-elastic armchair single-walled (SW) carbon nanotube (CNT) with mass sensors resting on a polymer substrate. The analytical formulation accounts for small scale effects based on the Eringen’s nonlocal elasticity theory. The mathematical model and its differential equations are solved theoretically in terms of dimensionless frequencies while assuming a nonlinear Winkler-Pasternak-type foundation. The solution is obtained by means of ultrasonic wave dispersion relations. A parametric work is carried out to check for the effect of the nonlocal scaling parameter, together with the magneto-mechanical loadings, the foundation parameters, the attached mass, boundary conditions and geometries, on the dimensionless frequency of nanotubes. The sensitivity of the mechanical response of nanotubes investigated herein, could be of great interest for design purposes in nano-engineering systems and devices.

scholarly journals Detonation effects of shallow buried explosive in sandy soil on target plate acceleration in a small-scale blast test

2018 ◽  
Vol 192 ◽  
pp. 02028
Author(s):  
Hassan Zulkifli Abu ◽  
Ibrahim Aniza ◽  
Mohamad Nor Norazman
Keyword(s):  
Sandy Soil ◽  
High Speed ◽  
Early Stage ◽  
Time History ◽  
Video Camera ◽  
Small Scale ◽  
Target Plate ◽  
Air Blast ◽  
High Speed Video Camera ◽  
The Impact

Small-scale blast tests were carried out to observe and measure the influence of sandy soil towards explosive blast intensity. The tests were to simulate blast impact imparted by anti-vehicular landmine to a lightweight armoured vehicle (LAV). Time of occurrence of the three phases of detonation phase in soil with respect to upward translation time of the test apparatus were recorded using high-speed video camera. At the same time the target plate acceleration was measured using shock accelerometer. It was observed that target plate deformation took place at early stage of the detonation phase before the apparatus moved vertically upwards. Previous data of acceleration-time history and velocity-time history from air blast detonation were compared. It was observed that effects of soil funnelling on blast wave together with the impact from soil ejecta may have contributed to higher blast intensity that characterized detonation in soil, where detonation in soil demonstrated higher plate velocity compared to what occurred in air blast detonation.

The influence of different pre-formed holes on the dynamic response of square plates under air-blast loading

2017 ◽  
Vol 78 ◽  
pp. 122-133 ◽  
Author(s):  
Ying Li ◽  
Weiguo Wu ◽  
Haiqing Zhu ◽  
Zhen Wu ◽  
Zhipeng Du
Keyword(s):  
Dynamic Response ◽  
Blast Loading ◽  
Air Blast ◽  
Air Blast Loading

Small scale experimental study of the dynamic response of a tension leg platform wind turbine

2014 ◽  
Vol 6 (5) ◽  
pp. 053108 ◽  
Author(s):  
Anders Mandrup Hansen ◽  
Robert Laugesen ◽  
Henrik Bredmose ◽  
Robert Mikkelsen ◽  
Nikolaos Psichogios
Keyword(s):  
Experimental Study ◽  
Dynamic Response ◽  
Wind Turbine ◽  
Small Scale ◽  
Tension Leg Platform
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