Inter-fibre failure of through-thickness reinforced laminates in combined transverse compression and shear load

Extensive studies have been reported on the improvement of through-thickness reinforcement to inter-laminar performance of composite laminates; current understanding on the in-plane performance is relatively limited, although it is also concerned in industrial application. The influence of through-thickness reinforcement (Z-pinning) on the inter-fibre failure in compression of unidirectional laminates was investigated. Both unpinned and Z-pinned laminates were tested at four different off-axis angles, representing different combinations of transverse compression and in-plane shear stress. It was found that the stiffness of Z-pinned laminates decreased significantly in all off-axis angles. The failure strain and strength were reduced in shear dominated failure modes, while improved in the compression dominated failure modes by the presence of the Z-pins. A further investigation on the angle of failure plane was carried out and a comparison with analytical failure models is presented

Dynamic inter-fibre failure of unidirectional composite laminates with through-thickness reinforcement

Unidirectional composite laminates reinforced in the thickness direction with Z-pins are tested in tension and compression with different off-axis angles at high loading rate. A split Hopkinson bar setup and a high speed imaging system have been used for these dynamic tests. It is found that the inter-fibre strength was reduced by Z-pinning in tension and shear dominated failure modes, and the reduction from dynamic loading conditions is greater than that in quasi-static. However, the laminate strength was not significantly influenced by Z-pinning when loaded predominantly in compression. This difference was caused by the transition of failure mechanisms around Z-pins. The stiffness of the laminate was not affected by Z-pins at elevated strain rates, since the increased epoxy stiffness helped to make up for the stiffness loss due to reduced fibre volume fraction resulting from Z-pins

Dynamic bridging response of through-thickness reinforcement in composite laminates

The present experimental study aims to extend the understanding of delamination crack bridging mechanisms in Z-pinned laminates subjected to highly dynamic loading conditions. The bridging response of single Z-pins was characterized with both quasi-static and high loading rate. Standard delamination tests of Z-pinned laminates were carried out at varying velocity. The experimental results at both length scales showed that Z-pin efficiency in improving delamination resistance decreases with increasing loading rate

Del síntoma a la estructura

Both Freud and Lacan dedicated a large part of their work to structural diagnosis without failing to recognize the contributions made by classical psychiatry, and, from this discipline, each one developed his own clinical practice. Freud�s descriptions and definitions allow us to pinpoint a patient�s complaint that occupies the boundaries between paranoia and hysteria (hypochondriac delirium), while Lacan�s later theorizing facilitates our understanding of the particularities that characterize paranoid delusions. These references allow us to propound a differential clinical practice between neurosis and psychosis and position the cure to create a space in which to listen when the patient is psychotic.Tanto Freud como Lacan dedican gran parte de su trabajo al diagnóstico estructural sin desconocer los aportes de la psiquiatría clásica, a partir de la cual, cada uno desarrolla su propia clínica. Así, las descripciones y definiciones de Freud permiten ubicar la queja de una paciente cuyo diagnóstico se sitúa entre la paranoia y la histeria (delirio hipocondríaco). Las posteriores teorizaciones de Lacan facilitan la comprensión de las particularidades que caracterizan el delirio paranoide. Esas referencias permiten plantear una clínica diferencial entre neurosis y psicosis, y orientar la cura para dar un lugar a la escucha cuando se recibe a un psicótico