Search NASA⌕ Search

SEARCH · Search NASA

Results for “TRAC booms”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

9 records
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Solar Cruiser TRAC Boom Development

The TRAC boom studied is a 30 meter, high-aspect ratio and highly nonlinear structural element planned for the NASA Solar Cruiser spacecraft where it would serve as the solar sail’s skeletal system designed to deploy the packaged reflective sail membrane as well as support operational sail tension loads for flight. Key design drivers for this boom are understanding and characterizing load-deformation behavior and quantifying buckling performance–under flight conditions (zero gravity). Knowing that the full-scale solar sail system cannot be feasibly tested for flight conditions under Earth’s gravity, a building block approach is methodically followed to verify finite element analysis (FEA) predictions and to evolve the finite element model (FEM) accordingly, beginning with the lowest level complexity to match global elastic behavior to the highest level complexity to bound theoretical responses under conservative expected flight conditions. Although the testing campaign for the TRAC boom has not developed yet to produce a full-scale test data point that loads the boom to failure, the fidelity of simulations have evolved with success and warrant further interest and work on this high-aspect ratio, but highly stable, deployable structural boom.

Lee Nguyen↗
NASA NTRSDate not supplied

Analysis of Triangular Rollable and Collapsible (TRAC) Composite Booms under the Effects of Gravity and Twist

Finite element analysis is used to investigate Triangular Rollable and Collapsible (TRAC) composite booms. The TRAC booms are subjected to a suite of loading conditions, including in-plane bending, out-of-plane bending, and axial compression. Simulations containing as-designed boom geometry are performed, as are simulations with geometric deviations associated with the as-built conditions of a sample TRAC boom. Namely, a cross-sectional twist along the length of the boom is incorporated into the analysis to study the effect of the twist on the deformation characteristics of the boom. Twisting in the sample boom was observed after short-term storage in a rolled configuration and may be attributed to differential creep deformation between the inner and outer flanges of the TRAC boom. Simulations are conducted with and without the effects of gravity to understand the significance of gravity on testing conditions. Booms of three lengths are evaluated: 3 meters, 7.5 meters and 30 meters. The mechanical responses of the TRAC booms are discussed with reference to the effects of gravity, boom length and cross-sectional twisting. Gravity is found to have a more significant effect on boom mechanical response as boom length is increased. Cross-sectional twisting is found to have a more significant effect on boom mechanical response in the shorter booms.

High-strain composites↗
NASA NTRS2016

Thermal Deformation of Very Slender Triangular Rollable and Collapsible Booms

Metallic triangular rollable and collapsible (TRAC) booms have deployed two Cubesat-based solar sails in low Earth orbit, making TRAC booms the most popular solar sail deployment method in practice. This paper presents some concerns and solutions surrounding the behavior of these booms in the space thermal environment. A 3.5-cm-tall, 4-meter-long TRAC boom of Elgiloy cobalt alloy, when exposed to direct sunlight in a 1 AU deep space environment, has a predicted tip motion of as much as 0.5 meters. Such large thermal deflections could generate unacceptable distortions in the shape of a supported solar sail, making attitude control of the solar sail spacecraft difficult or impossible. As a possible means of mitigating this issue, the thermal distortion behaviors of three alternative material TRAC booms are investigated and compared with the uncoated Elgiloy baseline boom. A tenfold decrease in induced curvature is shown to be possible relative to the baseline boom. Potential thermal distortions of the LightSail-A solar sail TRAC booms are also examined and compared, although inconclusively, with available on-orbit camera imagery.

Stohlman, Olive R.↗
NASA NTRSDate not supplied

Analysis of Triangular Rollable and Collapsible Composite Booms Under the Effects of Gravity and Twist

Finite element analysis is used to investigate Triangular Rollable and Collapsible (TRAC) composite booms. The TRAC booms are subjected to a suite of loading conditions, including in-plane bending, out-of-plane bending, and axial compression. Simulations containing as-designed boom geometry are performed, as are simulations with geometric deviations associated with the as-built conditions of a sample TRAC boom. Namely, a cross-sectional twist along the length of the boom is incorporated into the analysis to study the effect of the twist on the deformation characteristics of the boom. Twisting in the sample boom was observed after short-term storage in a rolled configuration and may be attributed to differential creep deformation between the inner and outer flanges of the TRAC boom. Simulations are conducted with and without the effects of gravity to understand the significance of gravity on testing conditions. Booms of three lengths are evaluated: 3 meters, 7.5 meters and 30 meters. The mechanical responses of the TRAC booms are discussed with reference to the effects of gravity, boom length and cross-sectional twisting. Gravity is found to have a more significant effect on boom mechanical response as boom length is increased. Cross-sectional twisting is found to have a more significant effect on boom mechanical response in the shorter booms.

High-strain composites↗
NASA NTRSDate not supplied

Gravity Offloading and Analysis of Long Imperfection-Sensitive Elements (GOALIE)

Use of large-scale deployable structures (e.g., iROSA) can enable space exploration and science missions (e.g., ACS3, Solar Cruiser). Numerical models predicting behavior of deployable structures in microgravity are difficult to validate because ground testing of long, slender, and flexible booms is challenging due to the influence of Earth’s gravity. The GOALIE team is collecting data for model validation through experimental testing to increase confidence in numerical models. Redwire, Inc. provided a subscale (7 m) and a full-scale (30 m) Triangular, Rollable, and Collapsible (TRAC) boom to use for test development. Other boom designs may be tested in the future.

Composites↗
NASA NTRSDate not supplied

Using DIC for Long Slender Structures

High-strain composite deployable structures have been developed for systems such as solar arrays, camera masts or solar sailing propulsion elements. Composite booms in such applications are often flattened and then rolled into a small footprint for low-packaged volume and are then deployed in space. There is a need to obtain deformation for long, slender composite booms on earth through gravity offloading by suspending them vertically and applying distal end (tip) loads. Three-dimensional digital image correlation (3D-DIC), along with other measurement techniques, were used to obtain strain and displacement along the length of a 7.5 m subscale composite Triangular, Rollable, and Collapsible (TRAC) boom in preparation for full scale testing of a 30 m boom. However, incorporating 3D-DIC as a primary measurement tool on long, slender, high-aspect-ratio boom structures presents significant challenges. Challenges include small correlated area due to high aspect ratio, limited standoff distance due to size of test area, coordinate system alignment of multiple camera systems along the length of the boom, nodal mesh extraction for adequate test/analysis correlation, as well as measurement comparison between DIC and other instrumentation used such as fiber optic strain sensing (FOSS) and laser displacement tracking. The contents of the proposed paper will focus on techniques and methods for overcoming the previously mentioned challenges associated with applying 3D-DIC to long, slender boom structures. Results from subscale test along with lessons learned will be discussed.

Deployable Boom↗
NASA NTRSDate not supplied

Experimental Setup for Mechanically Testing Subscale Triangular, Rollable, and Collapsible Deployable Composite Booms

High-strain composite deployable space structures are used for space infrastructure and science applications such as solar array supports, antennae, camera masts, and lightweight structures supporting solar sailing propulsion ele-ments. Triangular, Rollable, and Collapsible (TRAC) deployable composite booms are one example of a high-strain composite deployable structure and were studied using novel experimental test and characterization methods developed under the Gravity Offloading and Analysis of Long Imperfection-sensitive Ele-ments (GOALIE) project. In the present work, a subscale 7-m-long TRAC boom was suspended vertically to orient gravity along the length of the boom. By ori-enting vertically, highly nonlinear and unstable behavior often encountered dur-ing horizontally oriented gravity offload testing of similar structures was reduced. Pretest analytical predictions of TRAC booms indicated three unique failure modes, loads, and locations for three unique loading cases of in-plane bending, out-of-plane bending, and axial compression. To investigate the predicted behav-ior, an experimental test was set up to impart mechanical loads to a subscale TRAC boom. The experimental setup, loading cases, and instrumentation used to characterize the mechanical response of a subscale TRAC boom are described in this paper.

High-strain composites↗
NASA NTRSDate not supplied

Experimental Setup for Mechanically Testing Subscale Triangular, Rollable, and Collapsible Deployable Composite Booms

High-strain composite deployable space structures are used for space infrastructure and science applications such as solar array supports, antennae, camera masts, and lightweight structures supporting solar sailing propulsion elements. Triangular, Rollable, and Collapsible (TRAC) deployable composite booms are one example of a high-strain composite deployable structure and were studied using novel experimental test and characterization methods developed under the Gravity Offloading and Analysis of Long Imperfection-sensitive Elements (GOALIE) project. In the present work, a subscale 7-m-long TRAC boom was suspended vertically to orient gravity along the length of the boom. By orienting vertically, highly nonlinear and unstable behavior often encountered during horizontally oriented gravity offload testing of similar structures was reduced. Pretest analytical predictions of TRAC booms indicated three unique failure modes, loads, and locations for three unique loading cases of in-plane bending, out-of-plane bending, and axial compression. To investigate the predicted behavior, an experimental test was set up to impart mechanical loads to a subscale TRAC boom. The experimental setup, loading cases, and instrumentation used to characterize the mechanical response of a subscale TRAC boom are described in this paper.

Experimental testing↗