Drilling of glass fibre reinforced plastic (GFRP) composite is different from metallic materials due to its mechanical properties. The drilling of this material may generate delamination of drilled holes on workpiece. The purpose of this paper is to investigate the influence of the cutting parameters, such as cutting speed and feed rate, point angle of drill and material thickness on delaminati...

Due to the mismatch of mechanical properties in composite laminates, propagation of delami-nation is considered as a severe damage mechanism in beams with various lay-up configurations. Delamination can be generated due to matrix cracking propagation or it can also be initiated due to the manufacturing process before using composite beams. Using a micromechanics model, this study is aimed to in...

Tissue patterning relies on cellular reorganization through the interplay between signaling pathways and mechanical stresses. Their integration and spatiotemporal coordination remain poorly understood. Here we investigate the mechanisms driving the dynamics of cell delamination, diversely deployed to extrude dead cells or specify distinct cell fates. We show that a local mechanical stimulus (su...

A recent variational mechanics analysis of microcracking damage in cross-ply laminates of the form [(S)/90n]s, where (S) is any orthotropic sublaminate much stiffer than [90n], has been extended to account for the presence of delaminations emanating from the tips of microcracks in the [902n]T sublaminate. The new two-dimensional stress analysis is used to calculate the total strain energy, effe...

Layered borosilicate zeolite precursor ERB-1P (Si/B = 11) is delaminated via isomorphous substitution of Al for B using a simple aqueous Al(NO3)3 treatment. Characterization by PXRD shows loss of long-range order, and TEM demonstrates transformation of rectilinear layers in the precursor to single and curved layers in the delaminated material. N2 physisorption and base titration confirm the exp...

Effect of elastic anisotropy on indentation-induced thin film interfacial delamination, especially, at the initiation and early growth stage, is examined. The indentation load is modeled as a constant pressure over an expanding semi-spherical cavity. The delamination process is approached by a cohesive zone model. The rest of the problem is formulated within the general anisotropic elasticity t...

Fiber reinforced polymeric composites can be employed for the construction of structures that are highly durable and easy to fabricate. At EMPA, a prototype footbridge with girders and deck made of pultruded composite sections has been designed and constructed. For thin-wall pultruded sections such as I-beam or T-beam, delaminations can form easily at the web/flange junction. If the delaminatio...

Impact tests were carried out on composite laminates and composite scarf repairs, while both were subjected to in-plane loading with tensile pre-strain levels up to 5000 microstrain. The results show that pre-straining of the composite laminates has no noticeable influence on the size of the delamination area for the given impact energy of 8 J, which represents a typical barely-visible impact o...

In the present research, the effects of delamination size and location on vibration characteristics of laminated composite beams are investigated both analytically and numerically. In the analytical method, the delaminated beam is modeled as four interconnected Euler–Bernoulli beams and the constrained and free mode models are both simulated. The differential stretching and the bending-extensio...