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 18 of 18 for “"High velocity impact"”.
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High velocity impact fracture
… of ductile structural components under high velocity impact are investigated numerically and theoretically. Attention is focused on the formation and propagation of through-thickness cracks, which is difficult to experimentally track down using currently available instruments. Studied …
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High-Velocity Impact of Metal Microparticles
… recent development of the laser-induced particle impact test (LIPIT) has enabled direct imaging of individual microparticles as they impact a substrate at velocities of hundreds or thousands of meters per second. This technique allows for precisely controlled high-throughput impact testing, …
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Investigation of Pore Pressures During High-Velocity Impact by a Free Fall Penetrometer
… for the dynamic flow effects due to the high-velocity fall and impact. The results show that using Bernoulli’s theorem coupled with the concept of pressure coefficients results in good agreement between measured and hydrostatic pressures during the free-fall and initial penetration stage. …
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Integrating Peridynamics to Material Point Method for Modelling Solids and Fracture Dynamics in High Velocity Impact.
… fragments with a MPM solver (especially in high speed impact scenarios), our second contribution is to formulate a rigorous coupling governing equation which integrates the state-based PD within the MPM scheme (Superposition- based MPM) that features an automatic fractures modelling scheme. …
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Protection of High-Voltage Transformer Bushings and Other Brittle Structures Against Impact
… to improve the fundamental understanding of the impact behavior of porcelain high-voltage (HV) transformer bushings under high-velocity impact, with a focus on their protection with feasible methods which could be quickly applied in service to prevent vandalism and other undesirable impact …
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The response of reinforced concrete slabs to hard missile impact
Impact loads result when a structure is hit by a missile. The two major considerations in designing for impact are the limitation of local damage and the control of the overall response of the target structural element. Local damage may include penetration, perforation, scabbing and/or punching …
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Using 3D Printing to Improve the Impact Resistance of Sandwich Panels
… can limit their performance in strength and impact resistance. Advances in 3D printing have created the potential to use new materials and create new geometries for sandwich panel cores to improve their impact resistance. A uniform-density honeycomb core made from ULTEM-1010 was designed. It …
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Fracture of aluminum naval structures
… loads such as underwater or air explosion, high velocity impact (torpedoes), or hydrodynamic loads (high speed vessels) is primarily caused by fracture. Traditionally, naval structures have been designed to resist yielding, buckling and fatigue, but not fracture. Consequently, adequate …
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Impact damage evaluation of high performance polymeric composite material systems
… in two parts. In Part I a nitrogen gas gun impact system developed at Virginia Polytechnic Institute and State University is described. Evaluation methods for impact damage resistance and impact damage tolerance as developed by K. T. Teh are presented as a basis for comparative analysis of …
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Experimental study of bubble rupture during shock-fluid interaction
Head injuries are associated with exposure to high energy explosive detonation. There are four distinct types of blast induced neurotrauma (BINT): 1) these caused by supersonic shock waves propagating in the atmosphere (primary), 2) high velocity impact of shrapnel and debris (secondary) 3) …
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Impact and energy absorption of laminated and sandwich composites
Advanced fiber reinforced composites combine high specific strength and stiffness. Advanced composites are currently being introduced into modern U.S. Navy ships to achieve weight savings, maintenance reduction, and signature reduction. These advancements manifest themselves in Naval ships as …
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Quantifying Plasticity and Temperature in High Velocity Microparticle Impacts
The Laser Induced Particle Impact Test, or LIPIT, is a benchtop experimental setup that enables in-situ observation of micron-scale particles impacting targets at velocities ~10-1500 m/s. Through a combination of the high velocity and small length-scale of the impact, strain rates exceeding 10⁷ /s …
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Investigation of factors affecting the sticking of insects on aircraft wing surfaces
… by which insects stick onto surfaces during a high-Velocity impact. Analyses including scanning electron microscopy (SEM), electron spectroscopy for chemical analysis (ESCA) and contact angle measurements of uncoated and polymer-coated aluminum surfaces have been performed. An air-gun was …
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Finite element analysis of shear band failure with particular reference to circular plate impact
… Particular reference is made to the normal impact between blunt projectiles and circular plates of thin to intermediate thickness. The thesis presents a two dimensional axisymmetric and plane strain finite element computer program related to the Lagrangian reference frame. A four node …
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Extension of the peridynamic theory of solids for the simulation of materials under extreme loadings
… of engineering, including protection materials, impact damage in turbine engines and high velocity impact in space, remains one of the key challenges in the field of computational mechanics. Despite significant advances, a fully robust and generally applicable computational framework for …
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A scalable computational approach for modeling dynamic fracture of brittle solids in three dimensions
… to be modified on-the-fly, a process which is highly complex and hinders the scalability of parallel implementations. However, for the DG method, discontinuities exist at element boundaries from the start of the calculation and so modifications of the mesh topology are unnecessary for …
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Next Generation Multifunctional Composites for Impact, Vibration and Electromagnetic Radiation Hazard Mitigation
… mechanical (i.e., quasi-static, vibration, and impact) and electrical properties of FRPs while retaining minimal weight is the subject of many ongoing studies. The primary objective of this dissertation is to investigate the fundamental processes for developing hybrid, multifunctional composites …
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Progressive damage analysis for aerospace composite structures subjected to impact loads
L'abstract è presente nell'allegato / the abstract is in the attachment