Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 76 for “"Impact Testing"”.
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Mechanics of Notched Izod impact testing of polycarbonate
… failure at relatively low loads. Notched Izod testing is a common qualitative measure of toughness of a material, measuring energy absorbed prior to failure under high triaxiality and high rate loading conditions. Much research has been done using Izod testing to compare the fracture energies …
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Laser-Induced Particle Impact Testing in High-Pressure Oxygen Environments
Particle impact ignition is an important source of metal fires in the high-pressure oxygen environments found in the turbines of oxygen-rich turbopumps. Understanding of particle impact ignition has been hindered by experimental challenges in reproducing this phenomenon under controlled laboratory …
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A high-velocity, high-momentum impact testing device for agricultural materials
Thesis (M.S.)--Michigan State University. Dept. of Agricultural Engineering, 1969
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Design, Fabrication, and Testing of an EMR Based Orbital Debris Impact Testing Platform
… system, as well as the design, fabrication, and testing of a newer and larger Mk. 2 railgun system. The Mk. 1.1 system is developed as a more efficient alteration of the original Mk. 1 system, but is found to be defective due to hardware deficiencies and failure, as well as unforeseen efficiency …
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Multiple Reference Impact Testing of Bridges Using a Network of Low-Cost Dynamic Exciters
<p>Multiple Reference Impact Testing (MRIT) is a form of Experimental Modal Analysis (EMA) that can be used to identify the dynamic properties of full-scale bridges. These dynamic properties include natural frequencies, mode shapes, damping ratios, modal scaling and modal flexibility. Since these …
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Development of Pole Impact Testing at Multiple Vehicle Side Locations As Applied To The Ford Taurus Structural Platform
A test method was developed whereby repeated pole impacts could be performed at multiple locations per test vehicle, allowing a comparison of energy and crush relationships. Testing was performed on vehicles moving laterally into a 12.75 inch diameter rigid pole barrier. Crush energy absorption …
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Guardian Cap Effectiveness on Reducing Impact Accelerations and Enduring Player Health at the Collegiate Football Level
Using the Prism Neuro System and conducting impact testing, the study looked to evaluate the effectiveness of Guardian Caps. The Prism Neuro system gave us the ability to test proposition and visual skills of MIT Football players in season and out of season, and analyze their performance. We …
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The Effect of Load Stabilizer Selection on Load Shift Within Unit Loads
… tested. Twenty unit loads for both vibration and impact testing were used, with 5 replications per load stabilizer. Container displacement and pallet-container displacement were measured, and the number of tares in the load stabilizer film, on the corners of the test units, after testing, was …
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Assessing the Efficacy of Bicycle Helmets in Reducing Risk of Head Injury
… specifying a minimal level of acceptable impact protection. However, the conditions surrounding cyclist head impacts are thought to be much more complex than the test conditions prescribed in standards and have important implications related to mechanisms of injury. The overarching aim of …
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Impact Biomechanics of the Head and Neck in Football
… the biomechanics of the head and neck during impacts in football. The research related to the head is geared towards advancing the current understanding of the mechanisms of mild traumatic brain injury, specifically by investigating head accelerations experienced by football players during …
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Vibrational Characteristics of Dummy Headforms
… and NOCSAE headforms are two headforms used in impact testing, though their vibrational characteristics are not well understood. They may have different kinematic responses in various impact scenarios if the impact excites any of their natural frequencies; resonance is especially likely to occur …
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Implementation of automated visual inspection machines in biopharmaceutical industry
… of automated inspection machines for product impact testing; and (3) ambiguous understanding of cost drivers when selecting an inspection method. The pain points mentioned above were addressed separately. First, experiments with modified plunger surfaces were conducted to determine their …
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Structural characterization of polyurethane foam and implications of aging
… properties after aging, but fractured with impact testing. Previously, processing ReCrete foam at elevated temperature resulted in a decrease of the modulus (stiffness), which was believed to be related to chemical changes during processing. In this thesis, chemical and structural analysis …
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Identification of dynamic properties of materials for the spent nuclear fuel package at elevated temperatures
… for the nuclear fuel package and the appropriate testing systems were identified [15]. Second, fixtures for tensile testing at elevated temperatures using two machines, namely MTS and Instron Dynatup testing machines were designed and manufactured to make them compatible with the room temperature …
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Design and Validation of Hardware-in-the-Loop Testbed for Proximity Operations Payloads
… is a new testbed design for CubeSat and payload testing and development. This research demonstrates a low-cost, hardware-in-the-loop testing apparatus for use with university CubeSat programs for testing throughout the different levels of the development process. The average university CubeSat …
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Microstructure and Mechanical Properties of WE43 Alloy Produced Via Additive Friction Stir Technology
… T5 condition. The toughness measured by Charpy impact testing also showed an increase over the base material. The relationships among tensile properties, Vickers microhardness, impact toughness, microstructure and thermal history are developed and discussed.
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Detection and characterization of impact damage in carbon fiber aircraft fuselage structure
… techniques need to be developed and tested. Impact damage on aluminum aircraft structures can be detected from obvious surface indications. This is not the case in composite aircraft structure. Large interply delaminations and substructure disbonding may occur as a result of an impact, often …
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A microstructural examination of duplex ferrite -martensite corrosion resisting steels
… Characteristic fracture modes developed during impact testing have been related to the grain morphology and the occurrence of non-metallic inclusions. It is shown that splits form parallel to the rolling plane when Charpy specimens are subjected to impact testing and that both impact energy and …
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Finite Element Modeling of Delamination Damage in Carbon Fiber Laminates Subject to Low-Velocity Impact and Comparison with Experimental Impact Tests Using Nondestructive Vibrothermography Evaluation
… common when composite laminates are subject to impact loading.</p> <p>Various finite element methods for analyzing delamination exist. In this research, a modeling strategy based on contact tiebreak definitions in LS-DYNA<sup>®</sup>was used. A finite element model of a low-velocity impact event …
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