Engineering topics
Cormarkovic, Velibor
Publications and source records attributed to Cormarkovic, Velibor.
Modeling and simulation challenges for softgoods in space deployable structures
This paper examines modeling and simulation challenges for deployable spacecraft structures with softgood components. Previous studies highlighted the numerical challenges due to the mixture of high stiffness and low stiffness contact in this class of structures. This paper examines the use of the commercial LS-DYNA nonlinear finite element code on a set of relevant benchmark problems.
Modeling and Simulation Challenges for Softgoods in Space Deployable Structures
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HabEx Baseline Telescope: Design & Performance Analysis
HabEx is one of four missions under study for 2020 Astrophysics Decadal Survey. It will directly image and spectroscopically characterize planetary systems in the habitable zone of Sun-like stars. Additionally, HabEx will perform a broad range of general astrophysics science enabled by 115 to 2500 nm spectral range and 3 x 3 arc-minute FOV.
Habitable-Zone Exoplanet Observatory (HabEx) Baseline 4-M Telescope Design and Predicted Performance
The Habitable Exoplanet Observatory Mission (HabEx) is one of four missions under study for the 2020 Astrophysics Decadal Survey. Its goal is to directly image and spectroscopically characterize planetary systems in the habitable zone around nearby sun-like stars. Additionally, HabEx will perform a broad range of general astrophysics science enabled by 100 to 2500 nm spectral range and 3 x 3 arc-minute FOV. Critical to achieving its the HabEx science goals is a large, ultra-stable UV/Optical/Near-IR (UVOIR) telescope. The baseline HabEx telescope is a 4-meter off-axis unobscured three-mirror-anastigmatic, diffraction limited at 400 nm with wavefront stability on the order of a few 10s of picometers. This paper summarizes the opto-mechanical design of the HabEx baseline optical telescope assembly, including a discussion of how science requirements drive the telescope’s specifications, and presents analysis that the baseline telescope structure meets its specified tolerances.
Mars Ascent Vehicle (MAV) Concept - Launch System Development
A Mars Ascent Vehicle (MAV) would be one component of potential Mars Sample Return (MSR) and would have to launch from the surface of Mars into orbit about Mars with a soil sample. A MAV is a small lightweight rocket that must survive various environmental conditions, including powered ascent through the Martian atmosphere. A concept for the MAV system design includes a launch tube mounted on top of a mobile rover or a stationary lander. The launch tube must thermally insulate the MAV on the surface of Mars, and then guide the MAV during the initial portion of the launch. A mechanical erector system is also necessary for moving the MAV and launch tube from a stowed configuration to a launch configuration. The launch system would have to perform these tasks while also meeting many design constraints. This paper is a systems engineering perspective that will examine the current development of the launch system including design concepts, design trades, driving issues, and analyses performed. Design trades include different launch configurations that would prevent rover or lander tip-over, as well as re-contact between the MAV and the launch tube. Additional trades include options for guiding the MAV out of the launch tube, whether using launch rails or sabots, and finding a reliable but simple mechanical erector system. Analyses include investigating the impact of ignition overpressure based on launch configuration, launch loads and sensitivities to the launch system design, and Entry, Descent and Landing loads. The key considerations for these design trades are overall system mass, size, and reliability.
An Evaluation of Structural Analysis Methodologies for Space Deployable Structures
Benchmarks are introduced for evaluating the performance of numerical simulations of space deployable structures. These benchmarks embody the key challenges of interest to future large space deployable structures, including large angle motion, contact between flexible bodies, and the presence of both soft and stiff mechanical components. The benchmarks were used in companion studies to evaluate the ADAMS multibody dynamics code, the LS-Dyna nonlinear finite element code, and the Sierra large-scale parallel nonlinear finite element code. In the past, only multibody codes would have been considered for this application. This study found that all three codes could be used for these benchmarks, a finding that may lead to larger scale, higher fidelity simulations in the future.
An evaluation of structural analysis methodologies for space deployable structures
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Impacting Earth: Testing and Analysis for Mars 2020 and Future Missions
No abstract available