Improving the strength of additively manufactured objects via modified interior structure

Download

index.pdf

Date

2018

Author

Al, Can Mert

Metadata

Show full item record

Item Usage Stats

225
views

175
downloads

This thesis study provides an approach to improve the durability of additively manufactured parts via modified interior structures by considering the stress field results from tensile loading conditions. In other words, the study provides an automated method, i.e., implicit slicing method, which improves the strength of the parts with infill structures modified according to the quasi-static Finite Element Analysis (FEA) results under tensile loadings, automatically. The parts which are used throughout the work are designed by using Rhinoceros3D which is Computer Aided Design (CAD) software by considering the ASTM D638 standard. In scope of this study, the interior structures of the designed parts are modified by using the developed algorithm in Grasshopper3D, which provides the strength improvements by the help of heterogeneous infill structures. The quasi-static FEA is performed in Karamba3D which works as a plug-in on Grasshopper3D. Interior structures are constructed by using the stress field results and the first principal stress vector directions under the tensile loading conditions. The G-Code file which is required to manufacture the parts via 3D printing is also obtained inside the constructed Grasshopper3D schema by using a Python scripting to be used for a DeltaWASP 3D printer. For the geometries, different methods were employed to construct the interior structures. Then, the method which gives the most durable parts was applied for different parts to prove the applicability of the approach. The tensile tests were performed by using the ASTM-D638 tensile testing standard. The first version of the developed method was a kind of manual method which provides strength improvement about 42%. Regarding the further steps of this thesis study, the method used to construct the infill structure was tried to be automated whic provides about 50% strength improvement.

Subject Keywords

Materials, Structural optimization., Strains and stresses., Loads (Mechanics).

URI

http://etd.lib.metu.edu.tr/upload/12621859/index.pdf
https://hdl.handle.net/11511/27116

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Improving the strength of additively manufactured objects via modified interior structure AL, Can Mert; Yaman, Ulaş (2017-04-28) This thesis study provides an approach to improve the durability of additively manufactured parts via modified interior structures by considering the stress field results from tensile loading conditions. In other words, the study provides an automated method, i.e., implicit slicing method, which improves the strength of the parts with infill structures modified according to the quasi-static Finite Element Analysis (FEA) results under tensile loadings, automatically. The parts which are used throughout the w...
Developing replaceable members for steel lateral load resisting systems Bozkurt, Mehmet Bakır; Topkaya, Cem; Department of Civil Engineering (2017) Steel structures utilize lateral load resisting systems to provide sufficient strength, stiffness and ductility. Damaged structures need to be either demolished or retrofitted to recover their initial properties after a major earthquake. In steel structures, damage is concentrated to predefined fuse members and most other members are designed to behave elastic under seismic events. In buckling restrained braced frames (BRBFs) and eccentrically braced frames (EBFs), the fuse members are well defined and can ...
Upgrading of slab-column connections using fiber reinforced polymers Binici, Barış (Elsevier BV, 2005-01-01) The results of an experimental program on upgrading of reinforced concrete slab-column connections subjected to monotonic shear and unbalanced moment transfer are presented in this study. Externally installed carbon fiber reinforced polymer (CFRP) stirrups acting as shear reinforcement around the slab-column connection area were used with two patterns of CFRP arrangements. It was found that the proposed method resulted in punching shear capacity increases up to 60% relative to the specimen without any stren...
FINITE-ELEMENT ANALYSIS OF PRESTRESSED AND REINFORCED-CONCRETE STRUCTURES ELMEZAINI, N; CITIPITIOGLU, E (American Society of Civil Engineers (ASCE), 1991-10-01) A practical and powerful technique for the discrete representation of reinforcement in finite element analysis of prestressed and reinforced concrete structures is presented. Isoparametric quadratic and cubic finite elements with movable nodes are developed utilizing a correction technique for mapping distortion. Reinforcing bars and/or prestressing tendons are modeled independently of the concrete mesh. Perfect or no bond as well as any bond-slip model can easily be represented. The procedure is succes...
Lateral stiffness of steel plate shear wall systems Topkaya, Cem (Elsevier BV, 2009-08-01) The accuracy of the finite element method and strip method of analysis for calculating the lateral stiffness of steel plate shear wall (SPSW) systems is assessed by making comparisons with experimental findings. Comparisons revealed that while both methods provide acceptable accuracy, they also require the generation of sophisticated computer models. In this paper, two alternative methods are developed. The first one is an approximate hand method based on the deep beam theory. The classical deep beam theory...

Citation Formats

C. M. Al, “Improving the strength of additively manufactured objects via modified interior structure,” M.S. - Master of Science, Middle East Technical University, 2018.