K. Ramesh

Bio: K. Ramesh is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Photoelasticity & Stress intensity factor. The author has an hindex of 23, co-authored 125 publications receiving 1884 citations. Previous affiliations of K. Ramesh include Indian Institute of Technology Bombay & Indian Institutes of Technology.

Automation of data acquisition in integrated photoelasticity by phase-shifting technique

Abstract: In this paper a new whole field technique for determination of characteristic parameters in integrated photoelasticity using phase-shifting methodology is proposed. Appropriate optical arrangements necessary for this are presented and the intensity equations are obtained by Jones' calculus. The new methodology is verified experimentally for the problem of a circular disk under diametral compression viewed in oblique incidence.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Evaluation of Contact Stress and Fracture Parameters

Abstract: In many mechanical devices, there exist contact between two or more parts such as in gears, rolling element bearings, locomotive wheels and rails etc. The stresses caused by the pressure distribution between the bodies in contact are of importance in the design of these parts. Hertz [1] pointed out that in the absence of friction, the maximum shear stress occurs beneath the surface of contacting bodies. This leads to pitting of the contacting surfaces. The material lost from the surface due to pitting may get trapped into the contacting surfaces, causing abrasive wear. Smith and Liu [2] studied the effect of friction between the contacting surfaces. They reported that under certain conditions, the point of maximum shear stress could also occur at the surface of contacting bodies. The knowledge of contact zone and coefficient of friction between the contacting bodies is essential for evaluating the design of such contacting elements.

Durability Study on the Red mud-based Ternary Blended Geopolymer Concrete

Abstract: Concrete made with geopolymer technology is thought to be both pro-ecological and minimal cost-effective. Geopolymer concrete manufacture aids in the conversion of industrial by-product materials into reusable products. Geopolymer concrete outperforms OPC concrete in terms of strength. The ternary blended high-molarities (12M) geopolymer concrete used in this experiment was made of red mud (RM), fly ash (FA), and Ground granulated blast furnace slag (GGBFS). The current study intended to establish the best ratio of RM - FA - GGBFS -based ternary geopolymer concrete. The compressive strength, split tensile strength, and flexural strength tests were performed to determine the strength properties and water absorption, permeability, and sorptivity tests determined the durability characteristics. The results showes that the proportions of RM-based ternary GPC with RM: FA:GGBFS in 45:35:20 ratio resulted in a significant increase in the synthesis. This resulting in improved mechanical and microstructural properties than the other proportions. Higher results were also seen at the aforementioned ratio in the chemical analysis performed on the ternary-based geopolymer paste to determine the maximum pH value. The study's findings are encouraging sustainable and cost-effective routes for dealing with the industrial by-products that are presently produced in multiple regions.

Influence of the volume fraction of fibre-reinforced orthotropic composite on the mode-I stress intensity factor

Abstract: In the case of infinite bodies involving self-equilibrating loads, stress intensity factors (SIFs) for isotropic and orthotropic materials are the same. However, when the specimen is bounded, material orthotropy does influence the value of SIFs. Delale and Erdogan evaluated the mode-I SIF by solving singular integral equations numerically and showed that the SIF can be greater than the isotropic material value for certain types of orthotropic materials and can be smaller than the isotropic material value for certain other types of materials. They also observed that the mode-I SIF is not altered when either the crack is parallel or perpendicular to the fibre. These observations are verified by finite element analysis. The contours of iso-chromatics observable in a photoelasticity experiment are plotted to verify the suitability of finite element (FE) modelling and discretization. Using the FE code developed, the variation of the mode-I SIF for a single-edge notched (SEN) specimen as a function of v...

Recent developments in brittle and quasi-brittle failure assessment of engineering materials by means of local approaches

Abstract: Brittle failure of components weakened by cracks or sharp and blunt V-notches is a topic of active and continuous research. It is attractive for all researchers who face the problem of fracture of materials under different loading conditions and deals with a large number of applications in different engineering fields, not only with the mechanical one. This topic is significant in all the cases where intrinsic defects of the material or geometrical discontinuities give rise to localized stress concentration which, in brittle materials, may generate a crack leading to catastrophic failure or to a shortening of the assessed structural life. Whereas cracks are viewed as unpleasant entities in most engineering materials, U- and V-notches of different acuities are sometimes deliberately introduced in design and manufacturing of structural components. Dealing with brittle failure of notched components and summarizing some recent experimental results reported in the literature, the main aim of the present contribution is to present a review of some local approaches applicable near stress raisers both sharp and blunt. The reviewed criteria allowed the present authors to develop a new approach based on the volume strain energy density (SED), which has been recently applied to assess the brittle failure of a large number of materials. The main features of the SED approach are outlined in the paper and its peculiarities and advantages accurately underlined. Some examples of applications are reported, as well. The present review is based on the authors’ experience over more than 15 years and the contents of their personal library. It is not a dispassionate literature survey.

Some Basic Problems Of The Mathematical Theory Of Elasticity

Abstract: Thank you for downloading some basic problems of the mathematical theory of elasticity. As you may know, people have search hundreds times for their favorite readings like this some basic problems of the mathematical theory of elasticity, but end up in infectious downloads. Rather than reading a good book with a cup of coffee in the afternoon, instead they cope with some infectious bugs inside their computer.

Evidence for a protein transported through the secretory pathway en route to the higher plant chloroplast.

Abstract: In contrast to animal and fungal cells, green plant cells contain one or multiple chloroplasts, the organelle(s) in which photosynthetic reactions take place. Chloroplasts are believed to have originated from an endosymbiotic event and contain DNA that codes for some of their proteins. Most chloroplast proteins are encoded by the nuclear genome and imported with the help of sorting signals that are intrinsic parts of the polypeptides. Here, we show that a chloroplast-located protein in higher plants takes an alternative route through the secretory pathway, and becomes N-glycosylated before entering the chloroplast.

System for configuring a process control environment

Abstract: A control studio object system is disclosed which allows a process control environment to be easily and quickly configured or modified. The control studio object system includes a stencil portion having stencil items conforming to algorithms and a diagram portion to which the stencil items may be copied via a drag and drop operation. Because the stencil items are objects which contain all of the information required by a diagram portion to create an object that contains all of the information necessary to program the process control environment, the completed diagram portion reflects the actual configuration of the process control environment. Additionally, providing the stencil items as objects allows the diagrammed environment to be installed directly to nodes without requiring the diagram to be compiled or rewritten in a language conforming to the node.

Quality-guided phase unwrapping technique: comparison of quality maps and guiding strategies

Abstract: Quality-guided phase unwrapping is a widely used technique with different quality definitions and guiding strategies reported. It is thus necessary to do a detailed comparison of these approaches to choose the optimal quality map and guiding strategy. For quality maps, in the presence of noise, transform-based methods are found to be the best choice. However in the presence of discontinuities, phase unwrapping is itself unresolved and hence quality-guided phase unwrapping is not sufficient. For guiding strategies, classical, two-section, and stack-chain guiding strategies are chosen for comparison. If accuracy is the foremost criterion then the classical guiding strategy with a data structure of indexed interwoven linked list is best. If speed is of essence then the stack-chain guiding strategy is the one to use.