General Yielding of Charpy V-Notch and Precracked Charpy Specimens

Abstract

By applying a slip-line fields solution for general yielding, which includes the tup indenter for Charpy V-notch and precracked Charpy tests, estimates of high loading-rate yield stress values can be obtained. These values of yield stress are of particular interest for loading-rate sensitive materials such as low strength steels. Normal tensile tests are not performed at strain-rates indicative of impact tests; dynamic fracture toughness tests require the knowledge of dynamic yield stresses for the determination of validity limits for the fracture toughness measurements. This paper reviews the calculation of yield stresses from static and dynamic three-point bend tests and presents data for a nuclear pressure vessel steel which shows good agreement with high rate and conventional tensile test data.

Experimental Assessment of the Equivalent Strain Rate for an Instrumented Charpy Test

“…The quality of the correlations, quantified by the Pearson product-moment correlation coefficient 4 r, is summarized in Table 6. The strongest correlations (r ≥ 0.7) have been observed with total absorbed energy (KV), propagation energy (W p ), and the ratio between propagation and initiation energies (W p /W i ).…”

“…In 1978, Server proposed the following relationship for estimating the dynamic yield strength of a metallic material based on the force at general yield F GY [4]:…”

“…An important application of the characteristic force at general yield (F gy ), proposed by Server in 1978 [4], is the estimation of dynamic yield strength (σ YSd ) based on F gy values. The dynamic yield strength of a material is of particular importance for loading-rate sensitive materials such as low strength steels.…”

Comparasion of Impact and Tensile Properties of High-Strength Steel

“…If we substitute k for τ GY in Equation (1), then it is easy to derive the equation for the dynamic yield strength from Equations (1) and (3) [14].…”

Tenacidade à fratura translaminar dinâmica de um laminado híbrido metal-fibra titânio-grafite de grau aeronáutico

“…é o limite de escoamento dinâmico (SERVER, 1978), e P ed é a carga de escoamento correspondente, automaticamente reconhecida pelo sistema Charpy instrumentado.…”