Mathematical Modeling and Prediction Analysis of the Tensile Strength of DC01 Sheet Steel Based on Testing Speed

This paper presents a regression-based mathematical modelling approach for analysing and predicting the tensile behaviour of DC01 sheet steel as a function of tensile testing speed. Experimental tensile tests and regression-based prediction analysis were performed for testing speeds of 2, 4, 5, 7, and 10 mm/min, and the corresponding ultimate tensile strength (UTS) values were obtained from engineering stress–strain curves. Two specimens were tested at each speed level, and the mean values were used for regression analysis to ensure data consistency. A linear regression model was developed to describe the relationship between testing speed and tensile strength, showing a strong correlation between the variables with a coefficient of determination R² = 0.9968. In addition, a quadratic regression model was introduced to capture slight nonlinear behaviour and improve prediction capability. The developed models were also used to estimate tensile strength at intermediate testing speeds within the investigated testing range. A quadratic response curve analysis was also performed, allowing visualization of the relationship between testing speed and tensile strength. The results indicate that tensile strength slightly increases with increasing testing speed, reflecting the strain rate sensitivity of the material. The developed models provide a simple approach for analysing the influence of testing speed on tensile strength within the investigated range.