Percent Elongation
Calculate the percent elongation, A% = (L_f − L₀) ÷ L₀ × 100%, from the initial gauge length L₀ and the final length L_f measured after rupture in a tensile test (fitting the two halves of the specimen back together). The result, in %, is a direct measure of the material's ductility — how much it stretches before breaking. Ductile steels reach 20–40%; brittle materials, a few percent. Elongation depends on the gauge length used, so it is always quoted with it (e.g. A% over 50 mm). Enter the initial and final lengths.
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Alongamento percentual
O alongamento percentual é a medida mais direta e intuitiva da ductilidade de um material — o quanto ele consegue se esticar antes de romper. Calcula-se a partir do ensaio de tração: marca-se um comprimento de referência (gauge length) L₀ no corpo de prova antes do ensaio; depois da ruptura, as duas metades são reaproximadas e mede-se o comprimento final L_f entre as marcas. O alongamento é A% = (L_f − L₀) ÷ L₀ × 100%. Materiais dúcteis, como aços de baixo carbono e alumínio recozido, alongam-se 20–40%; materiais frágeis, como ferros fundidos e cerâmicas, rompem com pouquíssima deformação (1–2% ou menos). Um detalhe importante: o alongamento depende do comprimento de medida usado, porque a deformação se concentra na região da estricção (o 'pescoço' onde a peça afina antes de romper). Em corpos de prova curtos, essa deformação localizada pesa mais no percentual; em corpos longos, dilui-se. Por isso o alongamento é sempre informado junto com o gauge — por exemplo, 'A% = 25% em 50 mm'. Comparações só fazem sentido para o mesmo comprimento de referência. Informe os comprimentos inicial e final.
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True Strain
Calculate the true (logarithmic) strain, ε = ln(1 + e), from the engineering strain e (dimensionless or fractional). While engineering strain uses the fixed initial length as reference, true strain integrates the instantaneous length changes, being additive and better suited to large plastic deformations such as in metal forming (rolling, extrusion, drawing). The result is the actual strain accumulated by the material. For small strains, ε ≈ e; the difference grows as strain increases. Enter the engineering strain.
True Stress
Calculate the true stress, σ_t = s × (1 + e), from the engineering stress s (MPa) and the engineering strain e. Engineering stress uses the specimen's initial area, but during a tensile test the real cross-section shrinks; true stress corrects this using the instantaneous area (assuming constant volume in the uniform region), always giving a higher value than engineering stress. It is essential to build the true stress-strain curve and model strain hardening (σ = K·εⁿ). The result is in the same unit as the input stress. Enter the engineering stress and strain.
Tensile Strength from Brinell Hardness
Estimate a carbon steel's tensile strength (Rm) from the Brinell hardness, Rm ≈ 3.45·HB, in MPa. There is a remarkably robust empirical correlation between hardness and strength in steels, which lets you estimate strength from a hardness test — fast, cheap and almost non-destructive — instead of a tensile test. Useful in inspection and quality control. Enter the Brinell hardness (HB).
The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.