Delamination is one of the most common failure modes in composite structures. In particular, when the laminated composites are subjected to compressive loads, delamination becomes a constraint in the design process. In this study, the system is modeled as a plate supported by an elastic foundation. The elastic adhesive layer between the buckled sublaminates is represented by some parallel sprin...

patients and methods previously recorded data of 231 patients who underwent surgical closure of vsd between january 2009 and january 2012 at the rajaie cardiovascular medical and research center were retrospectively reviewed. vsd surgical repair was performed using continues suturing technique in group a patients (n = 163, 70.6%) and interrupted suturing technique in group b patients (n = 68, 2...

Composite insulations, such as ceramics, are commonly utilized in the turbine system a thermal coating barrier to protect metal substrate against high temperatures and pressure. The presence of delamination composite insulations may cause failure, leading catastrophic accident. Thus, regular non-destructive testing is required detect evaluate insulation defects. Among techniques, microwave tech...

As one of the important structures composite materials, polymethacrylimide (PMI) foam sandwich structure is prone to debonding and delamination defects during manufacturing service, which seriously affects mechanical properties materials. Therefore, it necessary detect structure. A linear frequency modulation infrared thermal wave nondestructive testing system was built study correlation betwee...

The characteristics of carbon fibre reinforced laminates had widened their use, from aerospace to domestic appliances. A common characteristic is the need of drilling for assembly purposes. It is known that a drilling process that reduces the drill thrust force can decrease the risk of delamination. In this work, delamination assessment methods based on radiographic data are compared and correl...

Beside the twist drill, the effects of various drill geometries were rarely discussed in analytical fashion. This study presents a comprehensive analysis of delamination in use of various drill types, such as saw drill, candle stick drill, core drill and step drill. In this analysis, the critical thrust force at the onset of delamination is predicted and compared with the twist drill. © 2003 El...

X-ray computed tomography (CT) has emerged as a key imaging tool in the characterization of materials, allowing three-dimensional visualization of an object non-destructively as well as enabling the monitoring of damage accumulation over time through time-lapse imaging. However, small defects and cracks can be difficult to detect, particularly in composite materials where low-contrast, plate-li...

A patient presented with chronic periapical periodontitis on tooth 45. The root canal was re-treated and a wide apical perforation was closed with MTA® as an apical plug. At reevaluation six month later, the tooth presented with increased mobility, bleeding on probing and probing pocket depths of 9 mm. Despite good periapical healing radio graphically, the tooth showed signs of localized margin...

We report a hafnium-containing MOF, hcp UiO-67(Hf), which is a ligand-deficient layered analogue of the face-centered cubic fcu UiO-67(Hf). hcp UiO-67 accommodates its lower ligand:metal ratio compared to fcu UiO-67 through a new structural mechanism: the formation of a condensed "double cluster" (Hf12O8(OH)14), analogous to the condensation of coordination polyhedra in oxide frameworks. In oxi...

Delamination fracture of a two-dimensional functionally graded multilayered four-point bending beam that exhibits non-linear behaviour of the material is analyzed. The fracture is studied analytically in terms of the strain energy release rate. The beam under consideration has an arbitrary number of layers. Each layer has individual thickness and material properties. A delamination crack is loc...