In this research, the thermal performance of the hybrid composites with modified epoxy matrix was investigated. The results were compared with those presented by the hybrid composites with homogeneous epoxy matrix. For understand the effects of the replacement of lower specific density glass fabric by higher specific density glass fabric, the thermal properties of the hybrid epoxy composites were determined by comparison to the thermal results of composites reinforced with lower specific density glass fabric with those of the hybrid epoxy materials reinforced with higher specific density glass fabric. Also, the effects on the specific heat and thermal expansion coefficient of the used fabric types in outer sheets of the composites were studied.

Due their various applications the fabric reinforced polymer composites are subject of a large number of researches especially for aero- and automotive industry. Regarding the last domain there are huge interests in designing and forming composites with controllable strengthens for car bodies able to protect both the driver and passengers inside and pedestrians in case of unfortunate events. In this regard, based on previous studies developed at the Research and Development Centre for Thermoset Matrix Composites, our proposal is to design the bending behaviour of a fabric reinforced materials by means of changing the bending strength of the polymer matrix using a solvent. 1-Methyl, 2- pyrrolidinone is a well-known polymer solvent that had been used in previous studies as vector to transfer various organic agents into epoxy resins. During those studies it had been noticed that the presence of above mentioned solvent is changing the bending behaviour of polymer samples and induces some properties that are belonging to memory-shape materials. The present study is related to mechanical analysis of a multi-layered material (fabric layers) immersed into an epoxy resin having a graded bending strength.

The thermal coefficient of linear expansion, the electrical conductivity and dielectric permittivity of fabric reinforced hybrid composites with filled stratified epoxy matrix were investigated. The measurements of electrical conductivity and dielectric permittivity had been performed, using standard method regarding electrical resistance and electrical capacity. In order to point out the effect of filler and of the spatial distribution of reinforcement layers, the medial layer of fabric was especially prepared by introducing copper wires in the woven. So, the medial layer is made of different types of tows (carbon, aramid, glass). This attempt is made in order to design a composite able to provide information about its state during various loading. The results showed that the fillers did not improve the electrical parameters of epoxy matrix, but they led to reduce the thermal coefficient of linear expansion. The thermal and electrical behavior of hybrid composites varied in dependence of number of carbon layers and fiber orientation.

this article presents some results of pin-on-disk tests on modified epoxy resins compared with the tribological behavior of the epoxy resin. The tribological response of materials was studied for three regimes force, sliding speed (F,v) of pin-on-disk geometry with the pin made of studied material and steel disk. All the tests were performed under thermos-vision surveillance to point out the temperature value modifications during tests and, at the end, the wear rate was evaluated for each materials. The modification of epoxy resins is an attempt to slightly change the some basic properties of the polymer such as electric conductivity but without changing their most valuable propertiesthermic dimensional stability, high adhesion to almost any other material and mechanical properties. One of the major disadvantages of epoxy resins is their chemical stability that makes them almost impossible to neutralize after their life cycle. In this regard the modification of epoxies by adding small amounts of organic or inorganic compounds could lead to an increase of their environmental acceptability.

Nowadays world is exposing a continuous spreading of composites applications and, as a consequence an enforcement of scientist efforts toward such materials design, testing and modelling. Since polymer reinforced materials are covering a huge area of applications it is obvious that the researchers interest is oriented to these materials study in all its aspects. Fabric reinforced polymers represent a very attractive solution from the manufacturers� point of view, especially in the case of thermoset polymers where the lay-up method is the most used to form composites. This study is about tensile behavior of lamina or plies of thermoset matrix fabric reinforced materials. The aim of the study is to determine the role of the matrix and the role of fabric (fibers type, specific weight) on the tensile response to gather valuable information regarding the design of layered materials.