1,721,145 research outputs found
The significance of indentation in the inspection of carbon fibre reinforced plastic panels damaged by low-velocity impact
No full textOn the penetration energy of fibre reinforced plastics under low-velocity impact conditions
No full text
The significance of indentation in the inspection of carbon fibre reinforced plastic panels damaged by low-velocity impact
No full textLow velocity impact tests were carried out at different energy levels on three types of T400/934 angle-ply laminates, using an instrumented drop weight apparatus. After impact, the indentation depth and the residual tensile strength were measured as a function of impact energy. Using the results obtained and experimental data available in the literature, an indentation law, allowing for the prediction of the impact energy from the depth of indentation, was assessed. The indentation law found seems to have a quite general applicability, being scarcely affected by the fibre type and orientations, and matrix type. A previous formula, modelling the residual tensile strength decay as a function of impact energy, was proven capable to correctly predict the residual strength results for all the laminates tested. Combining the indentation model and the residual strength model, a closed form model, explicitly correlating the residual strength and the indentation depth, was obtained. The theoretical predictions were in very good agreement with the experimental results. It is shown that the new model assumes a simple analytical form for a given laminate, permitting the material characterisation by a minimum of test data
Factors affecting the penetration energy of glass fibre reinforced plastics subjected to a concentrated transverse load
No full textOn the penetration energy of fibre reinforced plastics under low-velocity impact conditions
No full textThe paper deals with the prediction of penetration energy of fibre reinforced plastics subjected to low-velocity impact. Some results available in the literature are reviewed first, allowing to individuate the main parameters affecting the energy absorbing capacity of a composite laminate. It is shown that, for a given fibre type, the penetration energy is substantially influenced by the total fibre volume and tup diameter, whereas other factors, such as resin type and content, fibre architecture, stacking sequence and orientations, play a secondary role in the phenomenon. Then, an empirical power law equation recently proposed by the authors, from which the penetration energy can be evaluated, is assessed on the basis of experimental data previously published. The results indicate that the exponent of the power law is perhaps independent of the material considered, being practically the same for graphite fibre, as well as glass fibre reinforced plastics, and even for an isotropic material as polycarbonate, prone to extensive plastic yielding before final failure. The formula proposed, useful for in-plane isotropic and moderately anisotropic composites, can also permit the comparison of impact data generated under different impact conditions
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