Anil Patnaik

Bio: Anil Patnaik is an academic researcher from University of Akron. The author has contributed to research in topics: Titanium alloy & Corrosion. The author has an hindex of 13, co-authored 44 publications receiving 805 citations. Previous affiliations of Anil Patnaik include Curtin University & South Dakota School of Mines and Technology.

Horizontal shear strength of composite concrete beams with a rough interface

Abstract: The latest version of the ACI Building Code requires five equations to prescribe the limiting horizontal shear stress for differing amounts of reinforcing steel. The test results from the 16 beams tested in this study indicate that a more consistent limit can be obtained by replacing four of the present equations with a parabolic equation modified from the one used in the PCI Design Handbook. The proposed equation combines the effect of concrete strength and clamping stress. It is equally applicable for lightweight and semi-lightweight concrete. The test results indicate that an as-cast surface with the coarse aggregate left protruding for the surface, but without special efforts to produce a rough surface, can develop adequate shear resistance and simplify production of the precast concrete beams. Also, the tests show that stirrups are typically unstressed and ineffective until horizontal shear stresses exceed 1.5 to 2 MPa (220 to 290 psi).

Analytical models for concrete confined with frp tubes

Abstract: Concrete columns encased in fiber-reinforced polymer (FRP) tubes offer an attractive solution to enhance behavior of concrete in terms of strength as well as ductility. Analytical models for development of stress-strain curves for concrete confined with FRP are proposed in this paper. The predicted stress-strain curves for confined concrete using the proposed models are compared with those of tests for concrete specimens confined with FRP. It is demonstrated that the proposed models predict the stress-strain behavior of confined concrete very well. Based on the confidence gained in the proposed models, the effects of using different fibers, the presence of voids, and the number of layers are established.

A Study of the Tensile Deformation and Fracture Behavior of Commercially Pure Titanium and Titanium Alloy: Influence of Orientation and Microstructure

Abstract: In this paper, the tensile deformation and fracture behavior of commercially pure titanium and the titanium alloy (Ti-6Al-4V) are presented and briefly discussed. Samples of both commercially pure titanium and the Ti-6Al-4V alloy were prepared from the as-provided plate stock along both the longitudinal and transverse orientations. The specimens were then deformed to failure in uniaxial tension. The intrinsic influence of material composition and test specimen orientation on microstructure, tensile properties, and resultant fracture behavior of the two materials is presented. The conjoint influence of intrinsic microstructural features, nature of loading, and specimen orientation on tensile properties of commercially pure titanium and the Ti-6Al-4V alloy is highlighted. The fracture behavior of the two materials is discussed taking into consideration the nature of loading, specimen orientation, and the role and contribution of intrinsic microstructural effects.

A review on basalt fibre and its composites

Abstract: In recent years, both industrial and academic world are focussing their attention toward the development of sustainable composites, reinforced with natural fibres. In particular, among the natural fibres (i.e. animal, vegetable or mineral) that can be used as reinforcement, the basalt ones represent the most interesting for their properties. The aim of this review is to illustrate the results of research on this topical subject. In the introduction, mechanical, thermal and chemical properties of basalt fibre have been reviewed. Moreover, its main manufacturing technologies have been described. Then, the effect of using this mineral fibre as reinforcement of different matrices as polymer (both thermoplastic and thermoset), metal and concrete has been presented. Furthermore, an overview on the application of this fibre in biodegradable matrix composites and in hybrid composites has been provided. Finally, the studies on the industrial applications of basalt fibre reinforced composites have been reviewed.

A short review on basalt fiber reinforced polymer composites

Abstract: A recent increase in the use of ecofriendly, natural fibers as reinforcement for the fabrication of lightweight, low cost polymer composites can be seen globally. One such material of interest currently being extensively used is basalt fiber, which is cost-effective and offers exceptional properties over glass fibers. The prominent advantages of these composites include high specific mechano-physico-chemical properties, biodegradability, and non-abrasive qualities to name a few. This article presents a short review on basalt fibers used as a reinforcement material for composites and discusses them as an alternative to the use of glass fibers. The paper also discusses the basics of basalt chemistry and its classification. Apart from this, an attempt to showcase the increasing trend in research publications and activity in the area of basalt fibers is also covered. Further sections discuss the improvement in mechanical, thermal and chemical resistant properties achieved for applications in specific industries.

Manufacture by selective laser melting and mechanical behavior of commercially pure titanium

Abstract: Commercially pure titanium (CP-Ti) has received a great deal of attention in medical applications. Improvement of its mechanical properties plays a key role in enhancing the biomechanical compatibility of Ti implants, leading to avoid revision surgeries. Emerging advanced manufacturing technologies such as selective laser melting (SLM) is providing an ideal platform for producing components with almost no geometric constraints and is economically feasible down to a batch size of one. This study presents the results of using SLM to produce CP-Ti parts starting from powder with a wide grain size range up to 100 μm. Accurate manipulation of SLM manufacturing parameters were applied to produce nearly full dense (>99.5%) CP-Ti parts without any post-treatments. Compared with the properties of those manufactured by traditional processing technologies, the microhardness, compressive, and tensile strengths of SLM-processed CP-Ti parts have been improved to 261 Hv, 1136 MPa, and 757 MPa, respectively, due to the formation of refined martensitic α′ grains during SLM. The optimal manufacturing parameters could enhance the strength and hardness of CP-Ti and yet maintaining the ductility of titanium. Fractography study of the tensile-failed SLM-processed specimens showed that incompletely melted particles and porosities caused early fracture in porous sample. Mixture of dimples and minor quasi-cleavage facets covered most fracture surface of full dense sample.