Bratati Pradhan

Assessment of Beneficial Effects of Interference-fit in Pin-loaded FRP Composites

Interference-fit pin connections have wide applications ranging from aerospace structures to electric hardware systems and the telephone industry. In order to derive the maximum benefit by the use of interference-fit pin in all such applications, a complete understanding of their behavior in the regions of joints is essential. This paper deals with the study of various beneficial effects of interference-fit pin-loaded FRP composite laminates. Three-dimensional finite element models have been created to simulate interference-fit pin-loaded joints in various composite laminates. Non-linear contact analyses have been performed to study the effects of interference for different material cases on (a) circumferential edge stresses, (b) stresses across the weakest section (i.e., net-tension plane), and (c) the out-of-plane stresses around the hole periphery. It is observed that interference with specific value for each material case and laminate configuration is beneficial for better load carrying capabilities. Suitable interference for improved performance has been evaluated and recommended for each case. It is also emphasized that by interference-fit fatigue life of the joint can be improved.

Novel Silicone Rubber/Layered Double Hydroxide Nanocomposite: Preparation and Characterization

Silicone rubber (SR)/stearate ion modified Mg–Al–LDH (St-LDH) with 1, 3, 5, 8 % loading are obtained by the solution intercalation and characterized. Transmission electron microscope (TEM) of 3 wt % filler loaded SR nanocomposite confirms the exfoliation of St-LDH layers (thickness:1–2 nm, size:75–100 nm). Tensile strength, elongation at break and Youngs modulus of the corresponding nanocomposite are found to be maximum improved compared to neat SR by 97, 43 and 55 % respectively. SEM micrographs of the fractured surfaces show the uniform failure of the matrix without involving any crack initiation in neat SR, whereas roughly fractured surface with large number of microvoids are observed in the corresponding of SR nanocomposite. The improvement in the solvent-resistance properties of the SR/St-LDH nanocomposites is attributed to the excellent barrier properties of St-LDH layers and the exfoliated structure of St-LDH. The developed SR/St-LDH nanocomposites are expected to be a novel material with unique combination of mechanical and solvent resistance property.