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Full-Text Articles in Engineering
Characterizing Impact Induced Hot-Spot Morphology In Granular Solid Explosive, John Gilbert
Characterizing Impact Induced Hot-Spot Morphology In Granular Solid Explosive, John Gilbert
LSU Master's Theses
Deformation induced ignition of heterogeneous solid explosives is believed to originate at hot-spots within the material which are local regions of elevated temperature resulting from dissipative mechanisms such as plastic deformation and inter-particle friction. Inert meso-scale modeling of these materials can principally account for hot-spot formation enabling the characterization of hot-spot size and temperature distributions which are important for ignition but are di_x000E_cult to experimentally resolve. The focus of this study is to characterize hot-spot morphology, as well as the distribution of hot-spots, behind quasi-steady compaction waves computed from predicted temperature fields resulting from numerical simulations of rigid planar piston …
Low-Order Modeling Of Micro-Flier Impact With Thin Stationary Energetic Targets, Mark B. Fry
Low-Order Modeling Of Micro-Flier Impact With Thin Stationary Energetic Targets, Mark B. Fry
LSU Master's Theses
The impact of high-speed (500-1500 m/s), laser driven micro-fliers with thin energetic targets (10-100 &# 956;m) is being examined to characterize impact-induced heating and combustion of these materials. Aluminum fliers are propelled by a laser into a thin metallic target plate having a layer of energetic material deposited on its backside. Mass spectrometry is performed in vacuo on the energetic side to interrogate the shock-induced chemistry of the energetic material. It is important to ignite and possibly detonate the energetic material without perforation of the target plate avoiding contamination of the vacuum chamber. To guide development of these experiments, a …
Quasi-Static And Impact Characterization Of Sandwich Structures With An Iso-Grid Stiffened Syntactic Foam Core, Venkata Sandeep Chakka
Quasi-Static And Impact Characterization Of Sandwich Structures With An Iso-Grid Stiffened Syntactic Foam Core, Venkata Sandeep Chakka
LSU Master's Theses
In this study, a novel hybrid sandwich structure with an integrated, iso-grid stiffened syntactic foam core was fabricated and evaluated by impact test and static test. Sandwich beams with different grid cell areas were prepared using a pin-guided dry weaving process. Low velocity impact test on different locations (rib, node, and bay) was conducted with varying hammer weight and impact velocities by an instrumented impact testing machine. Ultrasonic C-scan was utilized before and after impact to identify the damage induced by impact. Scanning Electron Microscopy observation was also implemented to visualize the impact damage at micro- length scale. Compressions after …
Impact Damage Between The Collision Of A Vessel And Protective Fender Systems, Paul Joseph Kocke
Impact Damage Between The Collision Of A Vessel And Protective Fender Systems, Paul Joseph Kocke
LSU Master's Theses
Vessel collision with bridge pilings can cause a catastrophic event and are occurring at an alarming rate. Such events can lead to the collapse of a bridge, causing deaths, shutting down a primary route of transportation and costing millions of dollars in repairs. Today, the AASHTO Bridge Code gives designers a methodology toward designing bridge pilings to withstand the impact of an errant vessel. However, bridges designed before this code was written require a protective system that is capable of redirecting a colliding vessel without causing severe damage to the pilings or the vessel. This research will look into three …
Assessing The Needs For Intermediate Diaphragms In Prestressed Concrete Girder Bridges, Anand Kumar Chandolu
Assessing The Needs For Intermediate Diaphragms In Prestressed Concrete Girder Bridges, Anand Kumar Chandolu
LSU Master's Theses
Reinforced concrete Intermediate Diaphragms (IDs) are still being used in prestressed concrete (PC) girder bridges in Louisiana. Some of the advantages of providing IDs are disputed and also use of IDs increases the cost and time of construction. There is no consistency in the practice of providing IDs among various states and codes of practice and overall there is a lack of clarity on the effectiveness of IDs and their needs in prestressed concrete bridges. The objectives of this research are to assess the need of reinforced concrete (RC) IDs in PC girder bridges and to determine their effectiveness and …