A failure analysis investigation was performed on a fractured heavy duty truck frame rail obtained during endurance track testing. The fracture observed was on the frame web within the torque rod connection to the rear drive axle of the vehicle. This section of frame experiences multi-axial loading conditions including out-of-plane bending, twisting and shear under road loads. Metallographic ex...

This paper considers the explicit solutions of free-edge stresses near circumferential cracks in surface coatings of circular torsion bars and their application in determining the progressive cracking density in the coating layers. The problem was formulated within the framework of linear elastic fracture mechanics (LEFM). The free-edge stresses near crack tip and the shear stresses in the cros...

Because of the awkward and somewhat irregular shape of the weidment, conventional methods [I] could not be adapted to the nondestructive measurement of GT A W edge weid penetration on clamshell-style catalytic converters and a special inspection system based on the eiectric current deflection method was developed. DC or low-frequency AC electric resistance measurements, also known as the Potent...

We consider the scattering of an electromagnetic time harmonic plane wave by very thin obstacles. In this lecture we will restrict ourselves to the scattering of an Epolarized electromagnetic field by a perfectly conducting infinite cylinder having an open arc in R as cross section. We further allow the possibility that one side of the cylinder is coated with a dielectric material. This leads t...

The paper reviews the potential of the ultrasonic small incidence method of testing, which enables us to characterize smaller tight cracks quantitatively under load-free conditions. Recently, an important characteristic of the method of being capable of evaluating the cracks from both the accessible and inaccessible sides of material structures with almost similar level of sensitivity, has been...

ÐThe high-temperature fatigue-crack propagation and fracture resistance of a model g-TiAl intermetallic composite reinforced with 20 vol.% ductile b-TiNb particles is examined at elevated temperatures of 650 and 8008C and compared with behavior at room temperature. TiNb reinforcements are found to enhance the fracture toughness of g-TiAl, even at high temperatures, from about 12 to 040 MPa m, a...

We present a modeling technique for the interaction of an elliptical-shape crack in a metal with an open-ended waveguide. The crack is first modeled by an appropriate number of short rectangular waveguides. The mode-matching technique is then used to calculate the scattering matrix of the new segmented waveguide structure. The probe reflection coefficient of the dominant mode is finally calcula...

The size-effect, two-parameter, and fictitious crack models were developed to predict crack growth in materials like concrete that experience tension softening. The three models must predict the same response for infinitely large structures. Therefore, this study evaluates the differences in response for smaller structures. The metric used to compare response is the fracture toughness value req...

In this paper, the effect of interference fit on fatigue life of holed plate of mechanical joints was investigated experimentally. Fatigue tests were carried out on the holed specimens of Al-alloy 7075-T6 alloy. The interference fit process consists of force fitting a fastener into the hole with a negative clearance (diameter of the fastener is larger than of the hole) that produces beneficial ...

Three-dimensional enriched finite elements are used to compute mixed-mode stress intensity factors (SIFs) for three-dimensional cracks in elastic functionally graded materials (FGMs) that are subject to general mixed-mode loading. The method, which advantageously does not require special mesh configuration/modifications and post-processing of finite element results, is an enhancement of previou...