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Full-Text Articles in Aerospace Engineering

Data-Driven Damage Initiation Criteria For Carbon Fiber Reinforced Polymer Composites, Alexander Richard Post Nov 2021

Data-Driven Damage Initiation Criteria For Carbon Fiber Reinforced Polymer Composites, Alexander Richard Post

College of Computing and Digital Media Dissertations

Computational progressive failure analysis (PFA) is vital for the design, verification, and validation of carbon fiber reinforced polymer (CFRP) composites. However, the computational cost of PFA is usually high due to the complexity of the model. The damage initiation criterion is one of the essential components of a PFA code to determine the transition of a material’s state from pristine or microscopically damaged to macroscopically damaged. In this thesis, data-driven models are developed to determine the matrix damage initiation based on the Mohr-Coulomb model and Hashin model. For 2D plane stress states, the computational cost for determining damage initiation can …


University Of Minnesota Smallsat And High Altitude Ballooning Development And Collaboration, Luke Zumwalt, Ricardo Saborio, Athanasios Pantazides, Aaron Nightingale, Demoz Gebre Egziabher, Lindsay Glesener Oct 2017

University Of Minnesota Smallsat And High Altitude Ballooning Development And Collaboration, Luke Zumwalt, Ricardo Saborio, Athanasios Pantazides, Aaron Nightingale, Demoz Gebre Egziabher, Lindsay Glesener

2017 Academic High Altitude Conference

The Experiment for X-ray Characterization and Timing (EXACT) mission is a 3U CubeSat technology-development project being built by the SmallSat team at the University of MN – Twin Cities which is a joint research effort of the Aerospace Engineering and Mechanics (AEM) Department and the School of Physics and Astronomy (SPA). The main objective of this spacecraft is to carry a payload including a detector designed to measure energy and time of arrival time of individual hard x-ray photons emitted from the Sun and from other astrophysical sources. During the development process for EXACT, flights provided by the High-Altitude Student …


Solar Eclipse Induced Atmospheric Turbulence Effects On High Altitude Balloons, Fnu Anamika, Denise Buckner, Peter Henson, Jennifer Fowler, Nanette Valentour Oct 2017

Solar Eclipse Induced Atmospheric Turbulence Effects On High Altitude Balloons, Fnu Anamika, Denise Buckner, Peter Henson, Jennifer Fowler, Nanette Valentour

2017 Academic High Altitude Conference

The North Dakota Atmospheric Education Student Initiated Research (ND-AESIR) team launched a balloon during the total solar eclipse in Rexburg, Idaho. After the umbra’s passage, the balloon experienced unexpectedly high levels of atmospheric turbulence. Video footage taken from the payload displays the conditions, and analysis of flight path data models created from the iridium GPS confirm that unusually violent turbulence occurred. These forces caused the key rings holding the bottom of the parachute to the payload train to rip open; the balloon and parachute flew away and the payloads free fell to the surface from an altitude of 68,301 feet. …


How Iridium Satellite Tracker Model 9602-Lp Asset Affects Span Of Control In High Altitidue Balloning, Steven Hamby Oct 2017

How Iridium Satellite Tracker Model 9602-Lp Asset Affects Span Of Control In High Altitidue Balloning, Steven Hamby

2017 Academic High Altitude Conference

The Irdium Satelitte Network has greatly increased safety in the ballooning field by enabling a greater span of control in flight awarness and termination. This enhanced awareness stems from accurate high interval GPS coordinates that can be integrated into ground station tracking software. The Iridium Network creates the ability to send activation commands remotely with high reliabilty using emails. Additionally this feature has the ability to use local rf transmiters and recievers to increase the flexibilty of cutdown designs. The Iridium Modems provides significant coverage regardless of altitude and loss of ground communication. It is marketed at econmical price point …


Ground Station Tracking System, Garret Hilton, Carter Mciver, Steven Hamby, Trevor Gahl, Casey Coffman, David Schwehr Oct 2017

Ground Station Tracking System, Garret Hilton, Carter Mciver, Steven Hamby, Trevor Gahl, Casey Coffman, David Schwehr

2017 Academic High Altitude Conference

One of the Eclipse Ballooning Project’s main goals was to stream live video of the eclipse to the internet. To accomplish this task a tracking antenna was built to follow the balloon payload. As an added challenge, the task had to be completed on a budget. The “ground station” is the center for communication between the payload and user. This system utilizes GPS position reports from the payload via the iridium network to determine the balloons position. The computer algorithm takes in additional GPS and IMU data from the ground station to determine a relative heading to orientate the antenna …


High Altitude Balloon Flight Predictions, Sara Stafford Oct 2017

High Altitude Balloon Flight Predictions, Sara Stafford

2017 Academic High Altitude Conference

The ability to make accurate predictions of a high altitude balloon’s flight trajectory is critical for safety, protection of sensitive payloads, and ease of payload recovery. Several free software programs and websites are available which make predictions straightforward and yield acceptable results. Additional resources are presented which help evaluate the stability of the projected flight track. The various methods of prediction will be described and results compared with actual flight data.


Placing A High-Altitude Balloon In The Path Of Totality, Nicholas Jordan, Christopher Helmerich Oct 2017

Placing A High-Altitude Balloon In The Path Of Totality, Nicholas Jordan, Christopher Helmerich

2017 Academic High Altitude Conference

The UAH Space Hardware Club had conducted 70 flights prior to the Eclipse. In this time, we have gained valuable skills and experience which we have put into practice and passed on through the years. We put these skills into practice for the Eclipse. Our first challenge was finding where to launch. We started out by looking for suitable locations inside totality. We also examined a map of totality at 80,000 ft. We then ran predictions based on past weather during that time of year. By compiling multiple past predictions, we eliminated possible launch sites. We had multiple payloads, some …


Development Of A "Multi-Cut" Payload For Use In Stratospheric Ballooning Missions, James Flaten, Joey Habeck, Noah Biniek, Steven Smeaton, Austin Langford, Jordan Diers, Isaac Krieger Aug 2016

Development Of A "Multi-Cut" Payload For Use In Stratospheric Ballooning Missions, James Flaten, Joey Habeck, Noah Biniek, Steven Smeaton, Austin Langford, Jordan Diers, Isaac Krieger

2017 Academic High Altitude Conference

The ability to cut strings (AKA lines) during stratospheric ballooning missions has a wide variety of uses including, but not limited to, (a) flight termination (i.e. cutting payloads away from the main balloon), (b) cutting away excess lift balloon(s) to slow ascent rate (and possibly achieve float), (c) cutting away ballast weights to slow descent rate or increase ascent rate, (d) cutting away burst balloon(s) on descent to avoid parachute entanglement, and (e) cutting away payloads which are intended to return to the ground independently, for experimental purposes. We report on the development of a “multi-cut” payload box that uses …


Applying Newton’S Law Of Cooling When The Target Keeps Changing Temperature, Such As In Stratospheric Ballooning Missions, James Flaten, Kaye Smith, Erick Agrimson Jun 2016

Applying Newton’S Law Of Cooling When The Target Keeps Changing Temperature, Such As In Stratospheric Ballooning Missions, James Flaten, Kaye Smith, Erick Agrimson

2017 Academic High Altitude Conference

Newton’s Law of Cooling describes how a “small” system, such as a thermometer, comes to thermal equilibrium with a “large” system, such as its environment, as a function of time. It is typically applied when the environment is in thermal equilibrium and the conditions are such that the thermal decay time for the thermometer is a constant. Neither of these conditions are met when measuring environmental (i.e. atmospheric) temperature using a thermometer mounted in a payload lofted into the stratosphere under weather balloons. In this situation the thermometer is in motion so it encounters layer after layer of atmosphere which …


Directional Camera Control On High Altitude Balloons, Matthew M. Plewa, Brent Scharlau Jun 2015

Directional Camera Control On High Altitude Balloons, Matthew M. Plewa, Brent Scharlau

2017 Academic High Altitude Conference

The research reported in this paper examined the design and control of a gimbal for solar eclipse tracking and video recording. The gimbal design required 3 axes of rotation to allow for full range of motion. Utilizing individual brushless motors for each of the axes ensure minimum rotational requirements on each axes. In controlling the gimbal, both a mathematical and visual method were utilized. The mathematical method is a modified version of what is currently used for solar array pointing. The visual method looks at where the position of the sun is within the image and determines what angle changes …


An Overview Of A Solar Eclipse Video Payload, Alexander M. Peters Jun 2015

An Overview Of A Solar Eclipse Video Payload, Alexander M. Peters

2017 Academic High Altitude Conference

The HABET group at Iowa State University has been designing and building balloon payloads for years, giving students hands on experience with the engineering involved in creating and launching payloads to near space conditions. After attending the AHAC conference in 2014 the group begain to design a balloon for the 2017 solar eclipse. Working closely with the Space Grant Consortium’s design team, HABET has designed and completed preliminary testing on a Solar Eclipse Video payload. This payload uses multiple subsystems to complete the mission. The mission required an altitude control system, live video downlink, and a camera pointing system. Our …


Computational Fluid Dynamics Study Of Balloon System Tethered To A Stratosail, Jayakanth Loganathan, Kian-Meng Lim, Heow Pueh Lee, Boo Cheong Khoo Jun 2015

Computational Fluid Dynamics Study Of Balloon System Tethered To A Stratosail, Jayakanth Loganathan, Kian-Meng Lim, Heow Pueh Lee, Boo Cheong Khoo

2017 Academic High Altitude Conference

In this paper, we present a numerical study of a stratospheric balloon system tethered to a passive device, known as the Stratosail, for station-keeping operation. For scientific applications, stratospheric balloons that operate at altitudes between 15 and 20 km will need to maintain station over a fixed point above the earth for a prescribed period of time. This is a challenging problem due to the limitation of payloads and lack of an energy source. The present study uses computational fluid dynamics (CFD) simulations to analyze the drift velocity of such a balloon-Stratosail system under typical wind conditions in the stratosphere. …


Techniques For Payload Stabilization For Improved Photography During Stratospheric Balloon Flights, James Flaten, Christopher Gosch, Joseph (Benjamin) Habeck Jun 2015

Techniques For Payload Stabilization For Improved Photography During Stratospheric Balloon Flights, James Flaten, Christopher Gosch, Joseph (Benjamin) Habeck

2017 Academic High Altitude Conference

Payload-box rotation and swing are perennial challenges to achieving high-quality photography (typically videography) during weather-balloon flights to “near-space” (AKA the stratosphere). Continuous camera motion can lead to blurred still photos, nearly-impossible-to-watch video footage, and precludes time-exposure photography required for most astronomical imaging even though altitudes are reached where the daytime sky appears black. Apparently-random payload rotation, persisting even at altitude, can often exceed servo rotation rates and frustrate attempts to do active camera pointing. Here we discuss mostly-passive payload stabilization strategies we, and our collaborators, have used to mitigate and dampen both swing and rotation of suspended payloads on high-altitude …


The “Stratospheric Cricket Keeper” – Developing A Simple“Life-Support” Payload For High-Altitude Balloon Missions, Lucas Kramer, Chad Serba, James Flaten Jun 2015

The “Stratospheric Cricket Keeper” – Developing A Simple“Life-Support” Payload For High-Altitude Balloon Missions, Lucas Kramer, Chad Serba, James Flaten

2017 Academic High Altitude Conference

Exposure to the environmental conditions of “near-space” (AKA the stratosphere) is quickly fatal to nearly all forms of animal life. It is even challenging to build a sealable enclosure that can keep insects (crickets) alive through the dramatic and simultaneous pressure and temperature drops experienced during a high-altitude balloon mission. This poster describes the development of a rugged “cricket keeper” in which we were able to fly crickets to the stratosphere and, quoting the words of JFK, “return (them) safely to the earth!” This “life-support” payload had large windows (for the view!) and included Arduino-logged temperature and pressure sensors, an …


Using Tank Pressure To Determine The Lift Of A Balloon, Sarah M. Biver Jun 2015

Using Tank Pressure To Determine The Lift Of A Balloon, Sarah M. Biver

2017 Academic High Altitude Conference

An important aspect of high altitude ballooning is accuracy regarding the calculation of helium inflation in the balloon. If the balloon is over-filled it will increase rapidly in velocity and burst too quickly to record data. If the balloon is under-filled the rate of ascension will be too slow or not at all. This paper highlights the importance of accuracy in helium inflation by examining a method that uses pressure to control the inflation of a high altitude balloon. On every helium tank there is a pressure gauge, which can be used to monitor the change in pressure. Using that …


Parafoil Recovery Of A High Altitude Balloon Payload, Chelsea Velasquez, Zachariah Benedict Jun 2015

Parafoil Recovery Of A High Altitude Balloon Payload, Chelsea Velasquez, Zachariah Benedict

2017 Academic High Altitude Conference

The Recovery Guidance System is a subproject of Iowa State Universities’ High Altitude Ballooning Experiments in Technology (HABET) group. The system is designed to avoid common hazards during descent including large area objects such as populated areas and roadways, as well as smaller objects such as trees in a field, with an accuracy within tens of meters. RGS provides guidance for the payload using a two servo system aboard the payload in conjunction with GPS and radio communication. Navigation will be handled by a mixture of GPS and video analysis. For guidance, only longitudinal and directional dynamics of the payload-parafoil …


Autonomous Altitude Control Device For Latex Hab, John W. Siepierski Jun 2015

Autonomous Altitude Control Device For Latex Hab, John W. Siepierski

2017 Academic High Altitude Conference

The advent of latex High Altitude Balloons has dramatically reduced the costs associated with conducting research at altitudes reaching the stratosphere. Latex balloons are less expansive than zero-pressure and super-pressure alternatives, but they have an important disadvantage: while zero-pressure and super-pressure balloons can float at a desired altitude for long periods of time, latex balloons ascend continuously, flying only around two hours before reaching a bursting altitude (usually around 100,000 ft) and falling back to earth. Enabling latex High Altitude Balloons to float at a constant altitude for extended (and specifically defined) periods of time could make them significantly more …