Uma contribuição para a avaliação da incerteza associada ao módulo de elasticidade e aos limites de escoamento e de resistência. Implementação dos roteiros de cálculo em MATLAB

Abstract

This work aims to contribute to the evaluation of the measurement uncertainty associated with the modulus of elasticity and the yield and strength limits by implementing the calculation scripts developed by Antunes (2023) using the MATLAB®2019a software. All data used in this work were provided by Antunes (2023) during the performance of tensile tests on specimens made of AISI 4340 steel (28 HRC). To carry out this work, a detailed study of the test method, instrumentation and software used was carried out. After this initial analysis, all measurands, input variables and mathematical models used to calculate the measurement uncertainty of the modulus of elasticity and the yield and strength limits were identified. The GUM and Monte Carlo methods were applied depending on the complexity of the mathematical model in question. Three codes were created, whose structure was divided into blocks depending on the number of measurands considered. Furthermore, these codes were created in such a way that, during use, user interference is minimal. Code validation was carried out by comparing the results obtained via MATLAB®2019a and those resulting from the calculations performed by Antunes (2023) by using Excel. It was observed that the three codes allow the calculation of the uncertainty associated with the three mechanical properties under study adequately. For the combined standard uncertainty, the observed differences were less than or equal to 0.25 %. On the other hand, differences of up to 2.12 % were observed between the values of the expanded uncertainty of the modulus of elasticity