Publication Date
2021
Document Type
Dissertation
Committee Members
Ahsan Mian, Ph.D. (Advisor); Raghavan Srinivasan, Ph.D. (Committee Member); Daniel Young, Ph.D. (Committee Member); Joy Gockel, Ph.D. (Committee Member); Golam Newaz, Ph.D. (Committee Member)
Degree Name
Doctor of Philosophy (PhD)
Abstract
Sandwich structures are widely used for aerospace, marines and other applications due to their light-weight, strength, and strain energy absorption capability. The cores of the sandwich structure are typically fabricated by using high strength cellular materials such as aluminum and titanium alloys, or polymer foams, and honeycombs. Lattice cell structures (LCS) of different configurations such as body centered cubic (BCC), tetrahedron and pyramidal are being investigated as core material due to their design freedom and periodic nature. Due to the recent advent of additive manufacturing (AM), new research is being sought in the areas of designing and developing application-specific LCS configurations. However, experimental investigation of LCS is costly in time and materials. Therefore, in this dissertation, finite element models are developed using ABAQUS and validated according to previous experimental results to design application-specific LCS. First, an efficient and user-friendly tool was developed and this tool is called the Lattice Structure Designer (LSD). The LSD was developed from ABAQUS GUI and using Python scripting. This tool can be used to create the lattice models, define the materials, define the geometry, define the boundary conditions, apply loads, and submit the jobs to perform the computational analysis. The same tool can be used to access the database files and calculate any additional outputs. This ABAQUS plug-in has effectively helped to capture the responses beyond the plasticity levels and capture the failure mechanisms of the lattice structure. In this research, three types of lattices such as body centered cubic (BCC), tetrahedron with horizontal struts (TetH), and pyramidal (Pyr) are considered. These models are used to understand the failure mechanisms and relation between post-yielding deformations and the topologies of the lattice. All of these configurations were tested under compression in the z direction under quasi-static conditions and are compared with the FEA results. The post-yielding behavior obtained from FEA match reasonably well with the experimental observations providing the validity of the FEA models. Therefore, in this dissertation, finite element models are developed using ABAQUS and validated according to previous experimental results to design application-specific LCS. First, an efficient and user-friendly tool was developed and this tool is called the Lattice Structure Designer (LSD). The LSD was developed from ABAQUS GUI and using Python scripting. This tool can be used to create the lattice models, define the materials, define the geometry, define the boundary conditions, apply loads, and submit the jobs to perform the computational analysis. The same tool can be used to access the database files and calculate any additional outputs. This ABAQUS plug-in has effectively helped to capture the responses beyond the plasticity levels and capture the failure mechanisms of the lattice under compression and impact loads.
Page Count
184
Department or Program
Ph.D. in Engineering
Year Degree Awarded
2021
Copyright
Copyright 2021, some rights reserved. My ETD may be copied and distributed only for non-commercial purposes and may not be modified. All use must give me credit as the original author.
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.
