Banca de QUALIFICAÇÃO: JONAS MEDEIROS DE AZEVEDO BARBOSA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : JONAS MEDEIROS DE AZEVEDO BARBOSA
DATE: 15/12/2022
TIME: 16:30
LOCAL: Sala de CAx do Laboratório de Manufatura, NTI, UFRN
TITLE:

Numerical simulation of the punching in Advanced High Strength Steels (AHSS) at cryogenic temperatures

KEY WORDS:

AHSS, punching, criogenic, numerical simulation, finite element method, digital image correlation

PAGES: 57
BIG AREA: Engenharias
AREA: Engenharia Mecânica
SUBÁREA: Processos de Fabricação
SPECIALTY: Matrizes e Ferramentas
SUMMARY:

Advanced High Strength Steels (AHSS) are applied for vehicular structures aiming at a suitable balance between mechanical resistance and formability in manufacturing processes. These steels are commonly supplied in thin sheets and must be manufactured typically by forming and stamping operations to define the final shape of the mechanical component. One of the critical steps is punching, as the behavior of AHSS is a non-trivial approach when submitted to this forming process because it involves plastic deformation, ductile fracture, and shear brittle fracture. Furthermore, the material’s behavior changes during operation due to different parameters such as die clearance, punch geometry, and temperature. There are models to evaluate the effects of temperatures above the room in forming operations, but there is a lack of studies at cryogenic temperatures. This research aims to simulate the material’s behavior at cryogenic temperatures in the punching operation at room and cryogenic temperatures of the AHSS Bainite-Ferrite (FB590) steel to analyze the influence of the ductile-brittle transition in operation. To reach this goal, constitutive models considering elastoplastic and damage behavior must be calibrated so that the simulation properly represents the operation. A hybrid methodology for model calibration has been developed to allow the relationship between digital image correlation (DIC) and numerical simulation for the current material and other AHSS to be understood. The mechanical punching system, which will be applied for the experiments, has been modeled in a virtual environment, the finite element method has been implemented in Abaqus software, and a comparative analysis between the simulations and experiments is developed to validate the models. A shear specimen was developed, and the elastoplastic models were implemented in tensile simulations presented similar behavior compared with those in the literature for the same steel, with triaxiality values varying between 0.05 and 0.1.

COMMITTEE MEMBERS:
Presidente - 1792669 - ADILSON JOSÉ DE OLIVEIRA
Interno - 2266607 - FABIO JOSE PINHEIRO SOUSA
Interno - 1938946 - NICOLAU APOENA CASTRO
Externo ao Programa - 1451488 - JOÃO CARLOS ARANTES COSTA JÚNIOR - UFRN