Papers by Keyword: Woven Fabric Composites

Abstract: Vibration damping is proving important for improved vibration control and dynamic stability in advanced engineering systems like aerospace systems, automobiles and in ship building industry. In the present investigation, vibration characteristics of woven fabric carbon composite plate reinforced with micro rubber particle blended into epoxy matrix is studied for enhancing the vibration damping performance. Test Specimens are fabricated in the form of hand layup method. CTBN rubber particle size of 5μm is selected and added to the epoxy matrix for fabricating carbon/epoxy composite plates. Rubber particles of 3% & 15 % by weight were considered as blended percentage in epoxy matrix and compared with 0% addition of rubber particles for understanding and analyzing the vibration characteristics and its difference in damping performance. Vibration damping and modal responses of various kinds of prepared plates were studied and compared. Among tested samples, carbon/epoxy composite plate with 15 wt % micro rubber particle by weight showed very good damping performance.

Abstract: In order to simplify the performance analysis of woven fabric composites, the parametric micro-geometry model and APDL program are applied on elastic properties prediction. Firstly, the internal microstructure of woven fabric composites were observed using microscope. Seconldy, the parametric micro-geometry model was built using the defined equations to describe the shape of cross-section, the yarn path and their relations in Pro/e software. The cross-section of yarn was defined as ellipse curve ,while the yarn path was defined as sinusoidal and straight lines. Finally, the model was imported into ANSYS software, and the finite element analysis was carried out using the developed APDL program to obtain the elastic constants. With the proposed approach, several kinds of micro-geometry model of woven fabric composites were built automatically and their elastic constants were predicted quickly. It is shown that the predicted elastic constants are consistent with other references.

Abstract: Analytical models are presented for investigation of cure dependent stiffness of woven fiber composites. A linear-like correlation is adopted between the material properties and resin degree of cure. Fiber undulation model takes into account the fiber continuity and undulation and has been adopted for plain weave fiber mats geometry modeling. The analysis is performed on a unit cell, which is a representative of the entire fiber mat lamina. The classical laminate theory (CLT) is applied to determine stiffness constants in the infinitesimal region of the composites unit cell. The theoretical models can prediction the changes of stiffness matrices with the degree of cure. A case studies show that the elements of the stiffness matrices showed exponential increase with the resin degree of cure.

Abstract: Finite element analysis and corresponding experimental comparisons of temperature were performed to investigate the thermal behaviour of spherical plain bearings with self-lubricating fabric liner. Based on the theory of heat transfer, tribology and composite material mechanics, a sequentially coupled, 3D, thermo-mechanical finite element analysis model of the bearing system was built up, in which the steady-state temperature distribution from the thermal analysis was applied as a body load to the structural model. As a result, the maximum steady-state temperature of 78.1°C, von Mises stress of 299MPa, displacement of 0.0806mm along Z axis of the bearing are presented, together with the maximum contact pressure of 324MPa which are significant in the structural design and optimization of these bearings. The effect of temperature rise on the contact pressure distribution is discussed. The agreement of the temperature computation results with the experimental data indicates that this method could be used to analyze virtually any such bearing.

Abstract: The estimation method of the damping properties for woven composites has proposed. The proposed method has been applied to the plain woven composites. From these results, it is recognized that the computational damping properties have agreed with the experimental ones. Next, the effect of angle of fiber bundle on material damping of plain woven composites has investigated. The results show that the damping ratio is highest at angle of 45 degree.