#1German Reyes(UM: University of Michigan)H-Index: 6
#2Uday Sharma(UM: University of Michigan)H-Index: 2
Abstract The low velocity impact behavior of three layer thermoplastic laminates consisting of woven glass fiber and polypropylene has been investigated for two different fiber volume configurations. Panels with configurations of 50/50 and 20/80 in the warp and fill directions were subjected to low velocity impact energies between 4 and 16 J using an instrumented dropping weight impact tower. Load vs. displacement plots showed the excellent energy absorbing capabilities exhibited by the woven co...
Last. Enrique Barbero(ISCIII: Carlos III Health Institute)H-Index: 13
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This work focuses on an experimental study of flexural after impact behaviour of glass/polyester composite beams. The influence of impact energy, beam width, and impactor-nose geometry on the residual flexural strength was evaluated. Two widths of plain woven laminate specimens were selected. For each specimen width, the geometries of two impactor-noses (Charpy and hemispherical) were chosen to carry out impact tests using a three-point bending device, so that four different test configurations ...
The damage evolutions under low velocity impact were investigated using epoxy composite beams reinforced by S-2 glass, basalt, and Twaron 1000 fiber (identified as GFRP, BaFRP, and AFRP, respectively). GFRP showed a mutational damage mode, while BaFRP and AFRP represented a progressive one. The damage modes, the reductions in flexural strength and modulus in the direction of the impact face and the back face were compared based on the difference in fiber properties combined with fractography. Th...
Low velocity impact induced non-penetration damage in pultruded glass fibre reinforced polyester (GRP) composite materials was investigated using an instrumented falling weight impact test machine with a chisel shaped impactor. The characteristics of the impact event, force/time and force/deflection traces were determined. The internal damage was visualised and quantified by Electronic Speckle Pattern Interferometry (ESPI) in terms of the thickness, density and uniformity degradations of fringe ...
The aim of present work is to study the influence of low energy impacts on residual strength of carbon-epoxy laminates. Experimental tests were performed on [0,90,0,90]2s and [0,90]8 laminates using a drop weight-testing machine. The influence of the laminate stacking sequence is analysed under 1.5 J, 2 J, 2.5 J and 3 J impact energies, corresponding to a 0.91 ms-1, 1.05 ms-1, 1.18 ms-1 and 1.29 ms-1 of impact velocity, respectively. The impacted plates were inspected by CScan to evaluate the si...
#1V.P.W. Shim(NUS: National University of Singapore)H-Index: 36
#2L.M. Yang(NUS: National University of Singapore)H-Index: 8
Last. Liming Yang(NUS: National University of Singapore)H-Index: 24
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Abstract An investigation is undertaken to examine the residual mechanical properties of crowfoot-weave carbon/epoxy laminates subjected to a transverse central low-velocity impact load. It is found that the residual strength and stiffness of impacted laminates decrease with increasing impact damage area. Experimental data indicates that flexural stress constitutes the basis of a failure criterion that also describes damage severity, if localized damage at the region of impact is not serious. By...
Last. Hanafi Ismail(Universiti Sains Malaysia)H-Index: 60
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Studies on the flexural damage behaviors of satin and plain continuous-fiber-impregnated thermoplastic (COFIT) prepreg woven composites were carried out. Their weaving characteristics such as float length, interlace region, etc., which are believed to affect composite properties, were determined. It was found that the satin weave exhibits better flexural properties such as flexural strength and modulus than the plain weave system, with a more obvious trend in the 3-ply laminate system. The prese...
Abstract A triple plate finite element model was proposed to analyze delamination interaction in laminated structures. This model was verified by comparison with an axisymmetric finite element solution on a double delaminated structure. With this model, the results of delamination interaction in a three-point bending composite laminate and a circular laminated plate were obtained. In the case of a three-point bending laminate, both the bending crack induced and the shear crack-induced delaminati...
Last. Andy A Goodwin(Monash University, Clayton campus)H-Index: 11
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Abstract The flexural strength and interlaminar shear strength of stitched and non-stitched glass-reinforced plastic (GRP) laminates were studied under conditions of increasing impact energy and increasing number of repeated impacts. The GRP was stitched through the thickness with Kevlar thread in two orientations with a low or high stitch density. The Mode I interlaminar fracture toughness, GIc, increased with stitch density whereas the Mode II toughness, GIIc, was not changed by stitching. The...
Last. J.-L. Lataillade('ENS Paris': École Normale Supérieure)H-Index: 1
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The modelling of the behaviour of laminates during low velocity impact requires, first, an analysis of the efficiency of the numerical tool used. A logical development in relation to the numerical structure of the code and the experimental observations is proposed. Four aspects of the code implementation are discussed. The first one is the representation of the impact loading by a macro-contact model using the Lagrange multiplier technique. The second is the development of this technique on the ...