Effective application of FRP to concrete structure is not possible until a fundamental understanding of the mechanics and failure mechanisms of the retrofit system is available. This paper is mainly focused on developing a methodology for predicting the debonding failure caused by intermediate flexural cracks in FRP-strengthened R/C beam. Firstly, based on the strain compatibility, an iterative...

This paper presents an analytical model for investigating the effect of debonding between piezoelectric actuators/sensors and the host beam on the sensing and actuating behaviour. In this model, both flexural and longitudinal displacements of the host beam and the piezoelectric layers are considered using classical beam theory. For the adhesive layer, only through-thickness peel strain and tran...

The in vitro force levels generated by four differing methods of mechanical debonding techniques for ceramic brackets, using debonding pliers, were measured. The forces generated using wide (method W) and narrow blades (method N) were compared with those generated using a diagonally opposite corner application of the wide blades (method C) and incisal-gingival application of a pair of pointed b...

One of the most common failure modes of strengthened RC beams with externally bonded FRP is intermediate crack (IC) debonding of FRP initiated at the tip of flexural/shear cracks. This study presents a method, using extended finite element method (XFEM), to model IC debonding in an FRP-strengthened concrete beam. In XFEM, as soon as a damage initiation criterion is reached in an element, additi...

AIM The objective of the current epidemiologic study was to investigate characteristics associated with bracket failure in bonded brackets. MATERIALS AND METHODS A retrospective study on data of 144 patients treated during 2009 to 2012 was done. Baseline data including age, gender, malocclusion, bite type and debonding incidences per teeth were retrieved. ANOVA analysis and t-test were used t...

Criteria for progressive debonding at the fiber/mattix interface with friction along the debonded interface are considered for fiber-reinfoxed ceramic composites. The energy-based criterion is adopted to analyze the debond length, the crack-opening displacement, and the displacement of the composite due to interfacial debonding. The analytical solutions are identical to those obtained from the ...

BACKGROUND The aim of this clinical investigation was to compare the level of discomfort reported by patients during the removal of orthodontic metallic brackets performed with four different debonding instruments. METHODS The sample examined in this split-mouth study comprised a total of 70 patients (840 teeth). Four different methods of bracket removal were used: lift-off debonding instrume...

different techniques have been introduced for the removal of ceramic brackets. since the early 1990s, lasers have been used experimentally for debonding ceramic brackets. the goal of this study is to give a comprehensive literature review on laser-aided ceramic bracket debonding. pubmed and google scholar databases were used to identify dental articles with the following combination of key word...