Date of Graduation
12-2024
Document Type
Thesis
Degree Name
Master of Science in Civil Engineering (MSCE)
Degree Level
Graduate
Department
Civil Engineering
Advisor/Mentor
Barry, Michelle L.
Committee Member
Zhou, Wenchao
Second Committee Member
Prinz, Gary S.
Keywords
Additive Manufacturing; Concrete; Finite Element Analysis; Infill; Structural Engineering; Topology Optimization
Abstract
Additively manufactured concrete structures have potential to revolutionize civil infrastructure and allow for unique opportunities for built structures, expanding the variety of materials available and the geometries possible. The geometric freedom present in additive manufacturing techniques lends itself well to the use of novel geometries for infill patterns and overall structural design to improve structural performance and printed object characteristics. These improvements are the focus of this work and were conducted as a part of the ACME Tech program, which is sponsored by the US Army Corps of Engineers Engineer Research and Development Center (ERDC) and focuses on advancing AC technologies to enable expedient and efficient horizontal construction missions in a contingency environment.
A literature review on topology optimization, materials hybridization and optimization, and finite element analysis was first conducted to identify potential improvements in the structural design and performance of additively manufactured components. Then, finite element models of novel infill structures and arched culvert designs were developed to seek to improve object performance. A particular emphasis is placed on experimental and numerical approaches used to evaluate novel infill patterns and geometries and their application to large-scale horizontal construction missions, particularly within contingency environments where rapid and efficient construction is paramount. Four infill patterns -- hexagonal, triangular, linear, and cellular structures -- were compared to a solid specimen for their effectiveness in reducing material usage without compromising structural integrity significantly.
The findings presented suggest that optimized geometries, especially truss-like patterns, offer significant benefits, and the alternative infill patterns may be sufficient depending on structural requirements. The triangular infill pattern demonstrated superior performance in terms of weight- to-strength ratio, making it an ideal candidate for applications requiring lightweight yet robust structural elements. Furthermore, the novel arched culvert design developed exhibits compressive stresses in the arch section, but further work is required to model reinforcement in the bottom tie.
A further emphasis is made concerning the importance of compatible printer parameters and material characteristics to allow complex geometries to be printed successfully. Future studies may explore numerical topology optimization, additional loading cases, the scalability of these optimized designs, and the potential for incorporating reinforcement strategies, such as fiber reinforcement, to enhance the mechanical properties of printed structures. These insights contribute to the ongoing development of innovative construction technologies under the ACME Tech program, with potential applications in both military and civilian infrastructure projects.
Citation
Stewart, J. M. (2024). Investigation of Infill Patterns and Geometry Effects on the Compressive Performance of Additively Manufactured Concrete Structures. Graduate Theses and Dissertations Retrieved from https://scholarworks.uark.edu/etd/5599
