In components, crack propagation is subjected to crack-closure-mechanisms which affect the build-up of relevant threshold stress intensity factor range during cyclic loading. As structural parts are exposed service loads incorporating a variety load ratios, significant change long-crack value occurs, leading severe ratio dependency crack-closure-mechanisms. Thus, an extensive number experiments...

As fretting fatigue cracks are initiated at an early stage of life, the fretting fracture process is dominated by the stable growth of cracks. Hence the measurement of crack length is very important. This paper demonstrates the suitability of the DC potential drop technique for the measurement of fretting cracks. A calibration has been established for monitoring crack growth in BS L65 copper al...

Results are presented from a numerical investigation of the effect of the shape of the delamination front on energy release rate distribution in a laminated carbon fibre reinforced epoxy end-notched flexure test specimen. The deformation behaviour of the specimen has been computed by threedimensional nonlinear finite element analyses using a recently developed layered 3D-shell element. The dist...

http://dx.doi.org/10.1590/S1806-37132014000600013 The current intercostal nerve preservation strategy requires that care be taken when closing a thoracotomy. There are currently three thoracotomy closure techniques: • transosteal or transcostal suture closure • transperiosteal suture closure(5) • pericostal suture closure, whereby sutures are placed in the virtual space between the periosteum a...

A shell/3D modeling technique was developed for which a local three-dimensional solid finite element model is used only in the immediate vicinity of the delamination front. The goal was to combine the accuracy of the full three-dimensional solution with the computational efficiency of a plate or shell finite element model. Multi-point constraints provided a kinematically compatible interface be...

The fracture resistance of structures is optimised using the level-set method. Fracture resistance is assumed to be related to the elastic energy released by a crack propagating in a normal direction from parts of the boundary which are in tension, and is calculated using the virtual crack extension technique. The shape derivative of the fracture-resistance objective function is derived. Two il...

The paper presents a comparison of the results fatigue crack growth rate for raw rail steel, steel reinforced with composite material—CFRP—and also in case counteracting using stop-hole technique, as well an application “anti-crack fluid”. All specimens were tested constant load amplitude methods maximum loading Fmax = 8 kN and stress ratio R σmin/σmax 0.1 order to analyze efficiency different ...