Study of Variation of the J-integral and the Fracture Toughness in Blunt V-notches under Mode I Loading

Subject Areas : Journal of Simulation and Analysis of Novel Technologies in Mechanical Engineering

فاطمه نوری ازغد ¹ , حسن خادمی زاده ² , احسان براتی ³

1 - کارشناس ارشد، دانشکده مکانیک، دانشگاه آزاد اسلامی واحد خمینی شهر
2 - استادیار، دانشکده مکانیک، دانشگاه آزاد اسلامی واحد خمینی شهر
3 - استادیار، مجتمع مکانیک و هوافضا، دانشگاه صنعتی مالک اشتر

Received: 2015-09-27 Accepted : 2015-09-27 Published : 2013-12-22

Keywords:

Abstract :

Fracture assessment of U- and V-notches is important in mechanical engineering. One can use the J-integral as fracture parameter in order to predict the critical fracture load in notches. The critical value of the J-integral in cracks is a function of the material properties. In notches, however, the material properties as well as the notch dimensions affect this critical value (named fracture toughness). So, one should carry out a complex and time-consuming experiment in order to find the fracture toughness. In this paper, a practical equation has been derived to evaluate the critical value of the J-integral in blunt V-notches under Mode I loading. By means this new expression, only the notch dimensions and the critical value of the J-integral in cracks should be known. In this paper, the effect of the notch angle, the control volume radius to the notch root radius ratio (Rc/ρ), and the Poisson’s ratio on the J-integral and the critical value of the J-integral have been studied. Results have shown that by increasing the notch angle and the Poisson’s ratio, the fracture toughness decreases. However, the fracture toughness increases by increasing the Rc/ρ ratio.

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