The potential of piezoelectric ceramics on repair of delaminated structures subjected to a static loading is researched in the letter. A sliding fracture mode on two tips of a delaminated beam structure was uncovered by the author in a previous report. The stress singularity due to the fracture mode at the tips is attempted to be mended with a pair of piezoelectric patches by virtue of their el...

In this paper, the dynamic responses of cracked beams under different moving forces, including moving load, moving mass, moving oscillator, and four-degrees-of-freedom moving system, are investigated. Structural elements such as beams are designed to withstand the predicted loads, but unfortunately, they are always exposed to unpredictable damage such as cracks. Several factors may cause these ...

The effect of preexisting subsurface cracks on the strength of lap splices was investigated. Ten full-scale beams with No. 11 (No. 36) bars and lap splice lengths of 33, 79, and 120 in. (838, 2007, and 3048 mm) were tested. The beams had mitigating features that prevented catastrophic failure upon propagation of the preexisting cracks, such as staggered splices and the presence of some reinforc...

In the present work, fracture toughness (KIC) of full-depth (FD) fiber-reinforced concrete (FRC) and layered functionally graded (FGC) matrix cracked (MC) beams has been determined by equivalent relationships two-parameter model (ETPFM). Forty-eight MC-FGC MC-FD FRC beam specimens with span-depth ratios (L/d) equal 4, 5, 6 were tested under 3PB configuration. The MC length-depth ratio (ao/d) re...

This paper presents a unified approach to vibration analysis of functionally graded beams with transverse open-edge cracks based on the so-called shape obtained as general solution equations in frequency domain. The crack is modeled by pair translational and rotational springs stiffness computed from depth dependence upon material parameters. frequency-dependent functions allow one not only obt...

Cavitation damage in flexure bars crept at 1170°C was studied by a density measurement technique. The cavity density within the flexure beams could be approximated by a linear function of position from the tensile surface. A threshold stress for cavitation damage is suggested from the results of this study. Below the threshold tensile stress, cavitation ceases, whereas above the threshold, cavi...

The recently introduced concept of radially non-oscillating, temporally stable ultrashort-pulsed Bessel-like beams we referred to as needle beams is generalized to a particular class of highly localized wavepackets (HLWs). Spatio-temporally quasi-nondiffracting pulses propagating along extended zones are shaped from Ti:sapphire oscillator radiation with a spatial light modulator and characteriz...