Thesis Defense - Oğulcan Ahi (MSME)

Oğulcan Ahi – M.Sc. Mechanical Engineering

Assoc. Prof. Dr. Özkan Bebek – Advisor

Date: 27.07.2023

Time: 11.00

Location: AB1 246

FLOW RATE CONTROL SYSTEM UTILIZING RHEOLOGICAL PARAMETERS FOR PRECISE AND CONSISTENT EXTRUSION IN 3D CONCRETE PRINTING

Asst. Prof. Dr. Özkan Bebek, Özyeğin University

Assoc. Prof. Dr. Özgür Ertunç, Özyeğin University

Assoc. Prof. Dr. Çağla Meral Akgül, Middle East Technical University

Abstract:

The use of inline quality assessment technologies is of great importance in meeting the consistent extrusion requirements of 3D concrete printing (3DCP) applications. The proposed study suggests a system for regulating the extrusion speed during 3DCP processes in order to maintain the extrusion flow rate at a targeted value. This system is based on a newly proposed equation that combines printing parameters and the material's rheological properties in the printing process. The study presents a novel flow rate control method for 3DCP, leveraging a unique correlation between printing and rheological parameters to address quality assessment strategies in the process. The control strategy that has been proposed is established to function effectively with different types of cement-based mixtures and has the capability to regulate the extrusion process, thereby ensuring the attainment of a targeted flow rate from the system. Validation tests demonstrate that the proposed flow rate control can maintain an instantaneous flow rate within a certain range and eventually achieve a constant flow rate. During operation, the flow rate is consistently maintained around the targeted value, with an average error rate of 6.7 percent. The presented flow rate control mechanism exhibits promising potential as a reliable and efficient solution for achieving precise and constant flow rate values, regardless of the cement mix design employed.

Bio:

Oğulcan Ahi enrolled at Özyeğin University and obtained their Bachelor of Science degree in Mechanical Engineering in 2020. Continuing their academic journey at Özyeğin University, they successfully earned a Master of Science degree in Mechanical Engineering in 2023. During their Master's studies, Oğulcan Ahi had the privilege of submitting a paper, and with the support of their mentors and colleagues, their research was eventually converted into a patent.