International Journal of Fracture 91: 269–282, 1998. © 1998 Kluwer Academic Publishers. Printed in the Netherlands. Elastic stress distributions in finite size plates with edge notches P. LAZZARIN 1 , R. TOVO 1 and S. FILIPPI 2 1 Department of Engineering, University of Ferrara, Via G. Saragat 1, 44100 Ferrara (Italy); e-mail: tovo@ing.unife.it 2 Department of Mechanical Engineering, University of Padova, Via Venezia 1, 35131 Padova (Italy) Received 18 November 1997; accepted in revised form 2 July 1998 Abstract. In fatigue crack growth analysis it is essential to know the stress distributions in the neighbourhood of stress raisers. If such distributions ahead of the uncracked notch are known, stress intensity factors may be obtained via the weight function or other methods. The procedure described in the present paper reconsiders the principal elastic stress expressions already reported by the authors for infinite plates with semi-infinite symmetric V -shaped notches and adapts them to some practical cases, in which the mutual influence of the notches as well as that of the plate finite size play an important role in stress distributions. The aim is therefore to give an approximate close-form solution for the longitudinal stress, valid for the entire ligament length, namely from notch tip to notch tip. Theoretical and numerical stress values are compared on this line, examining plates with semicircular, V and U -shaped notches subjected to remote uniaxial tension. Key words: Stress fields, stress concentration factors, V -shaped notches, U -shaped notches. 1. Introduction The occurrence of geometric discontinuities is unavoidable in structural components, causing more or less localised perturbations of the stress fields. Whenever cyclic loading occurs, geo- metric stress raisers are preferred sites for fatigue crack initiation. To predict the fatigue life of a notched component, both crack initiation and crack propagation analyses are often needed. As is well known, stress concentration factors give only the maximum stress value and do not provide any information about other stress components, nor about the stress distribution ahead of the uncracked notch. Such a distribution is instrumental in the accurate determination of the crack driving force, e.g. the stress intensity factor for a crack emanating from a notch. The degree of accuracy for fatigue crack growth analysis largely depends on the accuracy used to describe the stress in the highly stressed region. The most known approximate expressions for notch-root longitudinal stress distribution were accurately checked by Shin et al. (1994a,b) against different notch configurations, each with a range of different notch acuity. To yield the best estimation of notch root stress dis- tribution along the axis perpendicular to the load direction, they suggested to use different expressions due to Chen, Glinka–Newport and Kujawski (1978, 1987, 1991), in conformity with stress concentration values. Since an examination of Chen and Kujawski’s expressions showed (1994a,b) that they tend respectively to underestimate and overestimate such a distri- bution, an expression based on their mean value was later suggested by Kujawski and Shin (1997), since it was natural to think it would have yielded a better approximation for a wide range of notches from blunt to sharp. 185000.tex; 31/07/1995; 12:10; p.1 Corrected (Kb. 2) INTERPRINT J.N.B./J.V./V.S. frac4453 (frackap:engifam) v.1.1