Optimization of Geometric Parameters and Material Properties for a Deployable Space Structure

Traveling to space requires a great deal of energy. This then limits the size of spacecraft accessible to transport to space. An optimization of a flexible tube that could be used as a satellite deployable structure was conducted by varying the cross section of the tube and its composite material properties. The material properties manipulated include the selection of a fiber, matrix, filler volume ratio, and orientation. HEEDS, a commercially available software, conducts the optimization process using the SHERPA algorithm. In the optimization, the finite element code, ABAQUS, iteratively performs two simulations. First, ABAQUS determines the stress distribution along the tube when wrapping the tube in its stored configuration. Second, ABAQUS finds the first natural frequency of the deployed structure. The objective function driving the optimization process is minimizing the weight and strain energy of the tube to create a light but highly flexible tube. This provides benefits of avoiding a violent deployment and lowering the dynamic response of the spacecraft during deployment. Three optimizations were performed with 1000 iterations each, using different initial geometries. While all three produce very similar results, one design converges to a clear best result. Using the best design, a series of deployment simulations are performed, using different boundary conditions to represent various scenarios. These boundary conditions include a free body dynamic response to deployment, a restricted response to only allow for rotation about the direction of deployment, and an increased damping deployment. Energy is dissipated differently comparing the results, showing that the most realistic case, being a free body deployment, has the lowest effect on the system. The spacecraft can dissipate energy by oscillating in the other axis. While damping does reduce the settling time for the deployed tube, there is notable oscillation in the middle of the tube seen in the transient state.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Aerospace Engineering

Department dc:contributor.department

Aerospace and Ocean Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2022

Author dc:creator

• Fink, Zachary Adam

Chair dc:contributor.committeechair

• Kapania, Rakesh K.

Committee members dc:contributor.committeemember

• Artis, Harry Pat
• Inoyama, Daisaku

• Deployable Structure
• Optimization
• Space Structure
• Composite
• FEM

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

vt_gsexam:34286

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/110393