Experimental analysis and numerical simulation of high loading rate crushing of honeycomb lattice structures

نوع: Type: thesis

مقطع: Segment: masters

عنوان: Title: Experimental analysis and numerical simulation of high loading rate crushing of honeycomb lattice structures

ارائه دهنده: Provider: Afshin Esmaeili Babadi

اساتید راهنما: Supervisors: Dr.Mehdi karimi

اساتید مشاور: Advisory Professors: Dr. Mohammad Heidari Rarani

اساتید ممتحن یا داور: Examining professors or referees: Dr. Hashem Mazaheri - Dr. Gholamhossein Majzoobi

زمان و تاریخ ارائه: Time and date of presentation: 2022

مکان ارائه: Place of presentation: Seminar 3 of the Faculty of Engineering

چکیده: Abstract: The advent of additive manufacturing technologies has made it possible to manufacture complex cellular materials, which, due to their unique property, such as lighter weight than simple solid structures and high energy absorption, are used in various industries such as automotive industries, protective equipment, aerospace industries, and medical implants, sports applications, etc. In this thesis, a star honeycomb structure is designed as a basic structure and an innovative structure has been made by combining two simple star honeycomb structures and arrow honeycomb structures with additive manufacturing technology and a Delta 3D printer. These two structures were tested under in-plane crushing at three speeds of 2 mm/min, 50 mm/min, and 150 mm/min. The results of the practical tests showed that increasing the speed in the quasi-static range does not have a great impact on the performance of the structure, but with the change in the geometry of the basic structure, important mechanical variables such as Poisson's ratio, energy absorption, average crushing force, and maximum crushing force will change. After that, numerical simulations are performed to further investigate the effects of crushing on the in-plane compression behavior of star honeycombs. The results show that by keeping the relative density constant and adding the arrow honeycomb structure to the base structure, the elasticity modulus of the structure increases greatly and the structure changes its behavior in the plateau area of the force-displacement diagram from two-stage force increase to one-stage. It shows more stability during crushing. Also, according to the deformation mechanisms of a typical cell, a theoretical model has been developed to predict the elastic modulus, Poisson's ratio, and bending deflection of star honeycomb under quasi-static loading. Finally, the Poisson coefficient of the structures has been obtained by the correlation process of digital images

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