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Full-Text Articles in Engineering Science and Materials

The Effects Of Uv Degradation On Polycarbonate Plastics Under Dynamic Compressive Loading, Hannah Bradford May 2024

The Effects Of Uv Degradation On Polycarbonate Plastics Under Dynamic Compressive Loading, Hannah Bradford

Honors Theses

The objective of this experiment was to analyze the dynamic properties of polycarbonate plastics subjected to accelerated ultraviolet (UV) exposure. This was done by subjecting rods of polycarbonate plastic to UV degradation in a QUV accelerated weathering machine for 375, 750, and 1500-hours. These rods were then tested under dynamic compression using a Split-Hopkinson Pressure Bar at an average strain rate of 1600/s. The Split-Hopkinson pressure bar works by rapidly compressing a sample between 3 axial rods sending an elastic wave through the sample. The strain gauges on the incident rod and the transmission rod transformed the elastic wave deformation …


Mechanics Of Pure Bending And Eccentric Buckling In High-Strain Composite Structures, Jimesh D. Bhagatji, Oleksandr G. Kravchenko, Sharanabasaweshwara Asundi Jan 2024

Mechanics Of Pure Bending And Eccentric Buckling In High-Strain Composite Structures, Jimesh D. Bhagatji, Oleksandr G. Kravchenko, Sharanabasaweshwara Asundi

Mechanical & Aerospace Engineering Faculty Publications

To maximize the capabilities of nano- and micro-class satellites, which are limited by their size, weight, and power, advancements in deployable mechanisms with a high deployable surface area to packaging volume ratio are necessary. Without progress in understanding the mechanics of high-strain materials and structures, the development of compact deployable mechanisms for this class of satellites would be difficult. This paper presents fabrication, experimental testing, and progressive failure modeling to study the deformation of an ultra-thin composite beam. The research study examines the deformation modes of a post-deployed boom under repetitive pure bending loads using a four-point bending setup and …


Sensitivity Analysis Of The Johnson-Cook Plasticity Model For Hypervelocity Impacts: A Hydro-Code Study, Carlos David Castellanos Jan 2010

Sensitivity Analysis Of The Johnson-Cook Plasticity Model For Hypervelocity Impacts: A Hydro-Code Study, Carlos David Castellanos

Open Access Theses & Dissertations

Computer simulations have been in use for decades in the modeling of hypervelocity impacts and general large deformation problems. Several computer codes have been developed to simulate this type of problems under a variety of geometric configurations and for any number of materials. These codes make use of several constitutive material models to simulate the response of the material under a variety of thermo-mechanical conditions. The Johnson-Cook constitutive model is widely used in the simulation hypervelocity impacts for the simulation of crater formation and even perforation of target structures. This thesis presents the results of a sensitivity study of this …