Testing Of Composite Panels Research Articles

Investigation of hybridization effect on ballistic performance of multi-layered fiber reinforced composite structures

The aim of this study is enhancing the ballistic performance of multi-layered fiber reinforced composite structures by hybridization approach against fragment simulating projectile (FSP). For manufacturing of homogeneous and hybrid composite structures, 170 g/m2 twill weave aramid and 280 g/m2 plain weave E-Glass fibers were used with epoxy resin systems and two different thickness values for each composite panel were fabricated and tested to obtain a relationship between areal density and V50 parameters. Tensile, 3-point bending, and short beam strength tests of composite panels were performed, and ballistic performance of composite structures were measured by V50 test method with 1.1 g FSP threat. Ballistic performance of hybrid composite structures was compared with high-performance composite ballistic panel test results reported in literature. As a result, it was found that E-Glass fabric layers together with aramid fabrics increased the energy absorbing capability of hybrid composite panels and ballistic performance was enhanced to be similar or higher than ballistic fiber reinforced composites. Hence, hybridization was found to be an effective way to enhance ballistic performance of fiber reinforced composite structures.

Testing of Composite Panels Used as Components of a Freight Wagon by Thermovision

Abstract In this paper research methods for detection of laminate panels damage were presented. The most common damage is: matrix cracking laminate interlayer damage to joints, connecting cracks, delamination and fiber breakage. The tested laminates will be used as assemblies and sub-assemblies of freight wagon. Other methods of modeling of machines by means of transducers are shown in Płaczek (2012, 2015) and Białas (2010). As part of the project authors were collaborated with specialists from other research centers and scientific research (Bocian and Kulisiewicz, 2013). As a part of future work the places where we will be able to replace the standard materials by parts made of laminate will be shown. Layered composites despite many advantages have also disadvantages. From last mentioned it is a relatively low resistance to transverse impact. When the laminate is used as a decorative element, its small damage is not a problem. The problems start when the composite satisfies more responsible tasks such as: is a part of the technical means for example of a railway wagon. Aspect of continuous monitoring of the technical state of the laminate is very important. Current technology provides numerous opportunities for non-destructive methods of technical inspections. In this paper method for testing of large areas, completely non-contact, based on the methods of thermography, was presented. It consists heating by using the composite tubes and examining it through a thermal imaging camera. Length of heating, and consequently the temperature to which the laminate is heated mostly were chosen experimentally. During the measurements, the camera measures the intensity of radiation, not temperature. Received thermogram is not always a precise representation of the actual temperature, because the camera does not reach only the radiation from tested object, but also reaches the radiation coming from the environment and reflected objects etc. As part of the research authors also we undertook other work related to Mechanical Engineering (Wróbel et al., 2008, 2010, 2012, 2013, 2015; Płaczek et al., 2014). Cooperation with other national and European centers has contributed to many publications of authors for example Tuma et al. (2013, 2014) and Jamroziak and Kosobudzki (2014).

Scattering of Obliquely Incident Electromagnetic Plane Waves by Composite Panel Involving Periodic Arrays of Circular Fibers

Electromagnetic scattering of a single-layer periodic composite panel is investigated. The panel is reinforced by a periodic array of infinite circular cylindrical fibers. A planar wave illuminates the panel with its wave vector orientated obliquely versus the fiber’s axes. In this 2.5-D scattering case, full-wave field representation from multipole and plane-wave expansions yield reflection and transmission coefficients of the longitudinal field components, which is achieved by mode matching at the boundaries. Power reflection and transmission coefficients are obtained from time-averaged Poynting vectors. The work is a prerequisite for modeling electromagnetic nondestructive testing of composite panels, approaching a multilayered structure made by stacking periodic slabs one over the other being the next step.

Simulation of impact response of multi-layered panels composed of bonded and unbonded plies

This paper presents an investigation into low velocity impact response of different configurations of resin bonded and unbonded layups of glass fabric composites for armour application. A numerical simulation was developed using the finite element code LS-Dyna to model the impact response at low velocities. The numerical results have been validated by comparison with results of impact tests on epoxy-bonded glass fibre-reinforced plastic plates with all edges fixed. Further impact testing of composite panels with various lay-up configurations have been performed using two different types of support: all edges fixed and with the panels mounted on clay foundation with all edges free. Experimental results show that a combination of unbonded flexible and adhesively bonded rigid composite lay-ups, which has a lower weight than fully bonded panels, yields comparable levels of energy absorption.