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Showing 1 to 20 of 24 for “"drop tower"”.
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Design of fixtures and specimens for high strain-rate tensile testing on a drop tower
Drop towers are used to perform mechanical tests at strain rates similar to those experienced in automobile crashes. By their nature, drop towers are configured to perform compression tests only. This project aims to design a set of fixtures and specimens to allow the machine to perform tensile …
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Ignition delay of oxygenated fuel droplets: development of a 1 second drop tower and initial 1-g test results
… butyrate combustion. In the present study, droplet ignition delay times of methyl butyrate and methanol are investigated. A bench experiment, conducted in normal gravity, was constructed and used to determine the ignition delay times of each fuel. Normal gravity experiments were conducted on …
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Physical Testing of Potential Football Helmet Design Enhancements
… required. In order to carry out this testing a drop tower was built based on National Operating Committee on Standards for Athletic Equipment, NOCSAE, specification. The drop tower designed for Cal Poly is a lower cost and highly portable version of the standard NOCSAE design. Using this drop …
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Experimental study of elasto-plastic wave propagation in one-dimensional and two-dimensional disk arrays
In this work, a drop-weight tower setup and a modified split Hopkinson pressure bar (SHPB) are used to dynamically load one- (1D) and two-dimensional (2D) arrays of disks in contact. The disks are made of aluminum 6061 T6 and are selected because of their rate-independence, thus allowing static …
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Development of the West Virginia University Small Microgravity Research Facility (WVU SMiRF)
… the Small Microgravity Research Facility (SMiRF) drop tower through a WVU Research Corporation Program to Stimulate Competitive Research (PSCoR) grant on its campus to increase direct access to inexpensive and repeatable reduced gravity research. In short, a drop tower is a tall structure from …
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Experimental Snap Loading of Synthetic Fiber Ropes
… synthetic fiber ropes. An eleven-foot-tall drop tower was built in the Virginia Tech Structures and Materials Laboratory in order to conduct these tests. Force and acceleration of the drop plate, which slides vertically within the drop tower, were measured with respect to time for all …
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The Influence of Impact Mass, Inbound Velocity and System Compliance on the Dynamic Response of a Hybrid III Head Form
… standards solely prescribe the use of vertical drop towers in their protocols; a mechanism which mimics the head impacting the ground. Athletes are more commonly injured via collisions with other players; however, and the current certification standards do not incorporate this mechanism of …
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Quenching of particle-gas combustible mixtures using the electric particulate suspension (EPS) method
… NASA Glenn Research Center's (NGRC) 2.2-second drop tower showed higher powder concentrations in microgravity compared to suspensions formed in normal gravity. Powder concentration profiles were confirmed to be symmetric at 0 g and a near-constant value under certain conditions. Abnormal …
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Pool boiling - growth of single bubbles at a heated wall
… the apparatus to go into free fall within a drop tower. Experiments were conducted at subatmospheric pressures using controlled nucleation so that the position and the thermal environment of the subsequent bubble growth were predetermined. Results of the experiments show that the temperature …
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Experimental Investigation of Liquid and Gas Fueled Flames Towards the Development of a Burning Rate Emulator (BRE) for Microgravity Applications
… layer separation. 0g ethanol wick flames from drop tower testing and airplane testing are shown.
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Impact Response and Failure of a Textile Composite Fuselage Frame
… circular circumferential frame segments using a drop tower apparatus. These frames have a nominal radius of 120 inches, a forty-eight - degree included angle, a thin-walled cross section in the shape of the letter J, and are typical of the transverse fuselage frames found in a large transport …
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Finite element modeling of a commuter category aircraft seat under crash loading
… was first validated against the results of three drop tests conducted in the Rowan drop tower. The model was then validated against a full fuselage drop test of a Beechcraft 1900C, conducted by the FAA. The model was shown to be an excellent predictor of pelvic acceleration. Reasonable agreement …
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Development of a punching technique for ductile fracture testing over a wide range of stress states and strain rates
… a new methodology based on an instrumented drop tower that will allow for testing of ductility for low to intermediate strain rates over stress triaxialities ranging from one third to two thirds. The methodology begins with a very in-depth understanding of plasticity based on multi-axial …
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Biomechanical Response of the Human Eye to Dynamic Loading
… different loading conditions to gather data. A drop tower pressurization system was used to dynamically increase intraocular pressure until rupture. Results for rupture pressure, stress and strain were reported. Water streams that varied in diameter and velocity were developed using a customized …
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Behavior of Magneto-Rheological Fluids Subject to Impact and Shock Loading
… MR dampers were subjected to impulsive loads. A drop-tower test facility was developed to simulate the impact events. The design includes a guided drop-mass released from variable heights to achieve different impact energies. Five drop-heights and two fundamental MR damper configurations were …
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Occupational Head Protection: Considerations for Test Methods and Use
… and three impact locations, using a twin-wire drop tower. Linear acceleration was used to predict injury risks. Type 2 hard hats substantially reduced skull fracture and concussion risk when compared to Type 1, indicating that if more workers wore Type 2 hard hats the risk of severe head …
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A laboratory simulation of low velocity projectile impact on thin plates
… based on the conventional instrumented drop tower apparatus, was designed and constructed. The apparatus is instrumented in order that the penetration resistance force history and impact velocity can be measured by a data acquisition system for further analysis. A software package, …
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Investigation into the immuno-therapeutic potential of melanocortin peptides on activated chondrocytes
… peptides. The antiinflammatory and chondroprotective effect of melanocortin peptides were then tested on in situ bovine articular chondrocytes, injured by a single blunt impact delivered by a drop tower. The mechanical injury caused significant cell death and up-regulation of the …
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Upper Extremity Interaction with a Helicopter Side Airbag: Injury Criteria for Dynamic Hyperextension of the Female Elbow Joint
… cadaver elbow joints. The energy source was a drop tower utilizing a three-point bending configuration to apply elbow bending moments matching the previously conducted side airbag tests. Post-test necropsy showed that 16 of the 24 elbow joint tests resulted in injuries. Injury severity ranged …
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Simulated impact trauma and osteoarthritis: the role of cell volume and mechanotransduction
… of single mechanical load and the effects of chondroprotective agents over short periods of time (2-30 min) post impact. Mechanical load (force 1.14 N) induced by a drop tower device caused cell death from as early as 2 min. Pre-incubation in hypertonic media protected chondrocytes from cell …
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