Composite structures

Concrete encased column which is developing rapidly in the construction field because of its advantages such as light in weight, faster in construction and no need of bar bending. This paper presents the behavior of the concrete encased steel tube column (CEST) by partially replacing the fine aggregate with the quarry dust, further shear connectors are also used to check whether they influence the strength of the column. Experimental investigations are done. Result showed that the partial replacement of quarry dust with shear connectors proved to have good axial load carrying capacity

In this paper is presented a new comprehensive approach to select cutting parameters for damage-free drilling in carbon fiber reinforced epoxy composite material. The approach is based on a combination of Taguchi’s techniques and on the analysis of variance (ANOVA). A plan of experiments, based on the techniques of Taguchi, was performed drilling with cutting parameters prefixed in an autoclave carbon fiber reinforced plastic (CFRP) laminate. The ANOVA is employed to investigate the cutting characteristics of CFRP’s using high speed steel (HSS) and Cemented Carbide (K10) drills. The objective was to establish a correlation between cutting velocity and feed rate with the delamination in a CFRP laminate. The correlation was obtained by multiple linear regression. Finally, confirmation tests were performed to make a comparison between the results foreseen from the mentioned correlation.

Keywords Abstract Composite Sandwich Structure; Structural Beams, Construction; Damage mechanisms In this review paper, the applications of composite sandwich structures in structural engineering are presented. Composite sandwich structures are getting a special attention in most engineering applications as they provide beneficial replacement to the traditional construction materials. This is attributed to their unique mechanical properties such as high specific flexural stiffness, ultra-low structural weight, excellent flammability and corrosion resistance. The use of composite sandwich structures in construction and housing, railway sleepers, huge building frames, and roofs is discussed in detail in this article. Furthermore, a comparison between the numerous types of composite sandwich structures and their most common applications is provided. Also, this study dedicates a section to review the damage mechanisms of composite sandwich structures.

A total potential energy approach has been employed in conjunction with the Rayleigh-Ritz method to study the stability behavior of generally laminated composite plates with all edges simply supported and subjected to in-plane loading conditions. Thorough comparison with exact solutions for some classes of laminated composite plates subjected to uniaxial compression and biaxial compression are presented to verify the theoretical prediction of the present analysis. Lastly parametric studies on the combination of the various in-plane loads, i.e., biaxial compression and uniaxial compression with shear, on practical laminated composite plates are presented. The buckling results for asymmetric angle-ply laminated composite plate are also discussed.

Nomex honeycomb cores have been widely used in composite sandwich panels. To accomplish meso-scale finite element modeling of these cores, cell wall mechanical properties are required, for which limited data are available. In this work, tensile testing was performed on Nomex paper, phenolic resin, and Nomex paper coated with phenolic resin. Flatwise tension and compression tests were also performed on two types of Nomex honeycomb cores. Test results were calibrated in finite element modeling to account for strain gage local stiffening effects and thickness normalization. Identified cell wall material properties were implemented in a honeycomb core finite element model and further calibrated by matching simulation results to manufacturer test data. The cells’ double-wall thickness was also adjusted. These calibrations and adjustments led to an exact simulation match with test data. Numerically matching cell wall material properties depends on modeling sophistication and is subject to core test result variability and core construction differences among manufacturers.