%0 Journal Article %T Sistema de baixo custo para nuclea£¿£¿o de pr¨¦-trincas por fadiga em corpos de prova de tenacidade ¨¤ fratura %A Guimar£¿es %A V.A. %A Hein %A L.R.O. %A Zangrandi Filho %A J. %J Materials Research %D 2001 %I ABM, ABC, ABPol, SBCC, SBCr, SBMM, SBPMat %R 10.1590/S1516-14392001000300011 %X fracture toughness testing becomes a very important parameter for mechanical design and maintenance of parts and structures. this work presents the design and construction of a machine device to perform the pre-crack nucleation on se(b) specimens for fracture toughness testing. employing this device, it is possible to test materials for kic, ctod and jic in a conventional tensile test equipment, assisted by a data acquisition system. the device is based on the concept of loading from an eccentric mechanism, controlling the displacement by means of a marking ring. the main contribution of this work is the low cost technology offered for laboratories, without high priced servo-hydraulic testing machines, giving them autonomy for the execution of fracture toughness tests. the experimental results satisfied the expectation about crack nucleation on se(b) and applied loading control. %K fracture toughness %K fracture mechanic %K mechanical testing. %U http://www.scielo.br/scielo.php?script=sci_abstract&pid=S1516-14392001000300011&lng=en&nrm=iso&tlng=en