In this thesis, the complete design, fabrication, and calibration of an instrumented drop weight impact tester is described. Included in this description are all the sketches and drawings that are needed to duplicate this project, if so desired. This impact tester was built for around $23,000 less than it would have cost to buy and modify a commercial tester for the intended research application. This tester, as designed, was intended to be used in the field of impact location detection using artificial neural networks. Even though this impact tester was built for a specific research application, the design concepts that are presented can easily be adapted to a variety of testing needs. This impact tester was built using an non-working milling machine for a base. This provides a rigid, stable base along with a moveable X-Y table. The tester itself has the capability for drop weights ranging from 3.518 Ib up to 15.408 lb, and impact energy levels ranging from 0.6 ft-lb up to 45.6 ft-lb. Also, it is capable of impacting multiple locations of large plates with variable boundary condition sizes up to 12" x 24". Furthermore, it uses a computer program written using a data acquisition software package to provide output plots for the impact event, including the force and energy applied to the specimen versus time and the force versus displacement. Finally, initial experimental results obtained from this tester agree very well with those obtained from a commercially available tester, allowing it to be used in future tests involving intelligent material systems. / Master of Science

Orientador: Itamar Ferreira / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-15T00:28:03Z (GMT). No. of bitstreams: 1 Kruger_EduardoLeira_D.pdf: 8976154 bytes, checksum: 7ee2f8d46393e64f855a07891a200250 (MD5) Previous issue date: 2009 / Resumo: O ensaio Charpy clássico, utilizado desde o início do século XX, permite determinar a energia global de fratura, propriedade mecânica conhecida como tenacidade. Esta energia tem caráter qualitativo e na aplicação no projeto estrutural, reduz-se a comparações entre as curvas de transição dúctil-frágil dos materiais. Com o surgimento da instrumentação do ensaio Charpy clássico é possível determinar a propriedade mecânica, tenacidade à fratura dinâmica, KId, muito utilizada na Mecânica de Fratura. O objetivo deste trabalho é analisar o sistema de instrumentação desenvolvido de acordo com a normatização ISO 14556(2000) para uma máquina de ensaio Charpy clássico, determinar e avaliar a tenacidade à fratura dinâmica, a partir do ensaio Charpy instrumentado, do aço AISI 4340 sob várias condições metalúrgicas obtidas através de tratamentos térmicos de têmpera e revenimento nas temperaturas de 473K, 573K, 673K e 773K. Foi observado que o sistema de instrumentação da máquina, a interpretação dos resultados dos esforços envolvidos no processo de fratura e o tempo para fratura são parâmetros de influência na determinação da tenacidade à fratura dinâmica. / Abstract: The classical Charpy test is used since 1900 and it is possible to determine from it the global energy for deformation and fracturing the specimen and this energy is named toughness which is important for selection steels considering ductile-brittle transition temperature. The Instrumented Charpy test is very important because it produces more material parameters, for example, the dynamic fracture toughness (KId), that can be used in Fracture Mechanics. However, there are several difficulties associated with the instrumentation of the impact machine ant processing digital signal, mainly in terms of the interpretation instrumented impact test results. The purpose of this work is to analyze the instrumentation system developed in accordance with normalization ISO 14556 (2000) to an Charpy machine and to determine and analyze the dynamic fracture toughness of the AISI 4340 steel in some metallurgical conditions obtained from treatment of quenching and tempering at 473K, 573K, 673K, and 773K. It was observed that the instrumentation system, the interpretation of the loads involved in the process of fracture and time to fracture are significant parameters in determining the dynamic fracture toughness. / Doutorado / Materiais e Processos de Fabricação / Doutor em Engenharia Mecânica