Chetan Jarali - Academia.edu (original) (raw)

Papers by Chetan Jarali

Civil Engineering Journal, 2019

High strength steel fiber reinforced concrete (HSSFRC) was prepared with the help of steel fiber.... more High strength steel fiber reinforced concrete (HSSFRC) was prepared with the help of steel fiber. 0.5%, 1.0%, and 1.5% steel fiber by volume of concrete specimen was used in concrete for present investigation. Compressive strength test and flexural strength test were conducted on cubical and prismatic specimens respectively.The main objective of the research work is to validate the experimental out comes by a numerical technique such as micromechanics approach. A high strength steel fiber reinforced concrete whose compressive strength is greater than 60 N/mm2 was prepared and tested on concrete testing machine. Flexural strength test was conducted on universal testing machine to evaluate the bending properties of concrete. It was observed that with increase in the percentage of steel fiber volume the compressive strength and flexural strength also increases. However the workability of concrete declines and concrete is no longer in working condition. Micromechanics technique helps to...

The research work presents the modeling of effective properties and thermo-mechanical behavior of... more The research work presents the modeling of effective properties and thermo-mechanical behavior of shape memory fiber (SMF) and shape memory polymer (SMP) composite laminates using micromechanical approaches based on the method of mixtures (MOM) and method of cells (MOC). The fiber is made of a nickel-titanium (Ni-Ti) shape memory alloy (SMA), while the matrix consists of a shape memory thermoset epoxy polymer (SMP). The use of an SMP matrix provides large strain compatibility with the SMA fiber, while being active at high temperatures without losing its elastic properties. Additionally, the SMP matrix is also able to produce similar pseudoelastic and shape memory effects, which are noticed in SMAs. In the analysis, a two step homogenization scheme is followed. In the first step the effective properties of each layer are determined via a micromechanics approach with iso-strain conditions. In the second step the effective properties of the SMF-SMP composite are computed making a thin ...

Journal of the Mechanical Behavior of Biomedical Materials, 2020

There is a great demand for the synthesis of acrylate based thermoset shape memory polymer (SMP) ... more There is a great demand for the synthesis of acrylate based thermoset shape memory polymer (SMP) associated with one monomer and one crosslinker such as tert-butyl acrylate (t-BA) with poly (ethylene glycol) dimethacrylate (PEGDMA). The present work describes the synthesis of a new thermoset SMP wherein a second monomer such as diurethane dimethacrylate (DUDMA) has been added to the existing tBA þ PEGDMA SMP matrix. The synthesized thermoset shape memory polymer exhibited a glass transition temperature (Tg) of 55 � C, higher Young's Modulus of 3.23 GPa, transmittance of 95% and 100% shape recovery. The SMP exhibited response to both thermal and chemical stimuli. The shape recovery rate of the SMP network is 20 s compared to 24 s observed for SMP based on tBA þ PEGDMA. The obtained SMP is very transparent and possesses higher stiffness (8 MPa) and hence may be suitable for biomedical shape memory lens and orthopedic application.

Analytical Applications of Graphene for Comprehensive Analytical Chemistry, 2020

Abstract The SP2 hybridized carbon gives rise to a trigonal structure of graphite. The single lay... more Abstract The SP2 hybridized carbon gives rise to a trigonal structure of graphite. The single layer of graphite named as graphene; is single atom thick layer which has got wide importance due to its high strength, high electrical and thermal conductivity. It is a two dimensional structure of hexagonal rings where carbon atoms are connected with each other by covalent bonds. The in-plane σ-bonds of graphene layer with energy of the order of 615 KJ/mol are stronger than the covalent bonds with energy of the order of 345 KJ/mol in SP3 hybridized diamond. The inter-plane п-bond which connects two adjacent graphene layers is weak as compared to σ-bonds. Therefore single layer of graphite can be sheared off with less energy. Graphene plays vital role in various energy storage devices like solar cells, supercapacitors, fuel cells and processes like electrocatalysis, etc. Therefore it is very important to explore the way graphene is synthesized and utilized. There are various ways like mechanical, chemical etc. to synthesis graphene from graphite flakes. However stability of graphene does not allow it to be effectively used as a catalyst. Graphene has been used in various extraction techniques. Therefore the focus of this chapter is to explore use of graphene in various extraction techniques.

Frontiers in Materials Processing, Applications, Research and Technology, 2017

ABSTRACT Shape Memory Polymers (SMPs) are currently popular in engineering morphing structures an... more ABSTRACT Shape Memory Polymers (SMPs) are currently popular in engineering morphing structures and bio medical applications. In the present work, we have synthesized a bio degradable SMP based on Poly (ethylene glycol) dimethacrylate (PEGDMA) as cross linker, in which tert (Butyl Acrylate) (tBA) is incorporated as co monomer. The SMP is polymerized by photo polymerization reaction. Further, the macro mechanical and thermal properties of the developed SMP are evaluated. Tensile tests have shown that increasing weight content of cross linker has reduced the elastic modulus significantly. SM properties are characterized by various methods, such as elevated temperature tensile experiments, cyclic thermal mechanical tests and physical shape recovery tests.

Materials, 2021

Microbial fuel cell (MFC) would be a standalone solution for clean, sustainable energy and rural ... more Microbial fuel cell (MFC) would be a standalone solution for clean, sustainable energy and rural electrification. It can be used in addition to wastewater treatment for bioelectricity generation. Materials chosen for the membrane and electrodes are of low cost with suitable conducting ions and electrical properties. The prime objective of the present work is to enhance redox reactions by using novel and low-cost cathode catalysts synthesized from waste castor oil. Synthesized graphene has been used as an anode, castor oil-emitted carbon powder serves as a cathode, and clay material acts as a membrane. Three single-chambered MFC modules developed were used in the current study, and continuous readings were recorded. The maximum voltage achieved was 0.36 V for a 100 mL mixture of domestic wastewater and cow dung for an anodic chamber of 200 mL. The maximum power density obtained was 7280 mW/m2. In addition, a performance test was evaluated for another MFC with inoculums slurry, and a ...

$Research paper thumbnail of Experimentation for flexural strength and fracture toughness on carbon and glass fibre self-healing composites with Bisphenol A diglycidyl ether and Amine microcapsules$

Composites: Mechanics, Computations, Applications: An International Journal, 2021

INTERNATIONAL JOURNAL OF MECHANICAL ENGINEERING AND TECHNOLOGY (IJMET), 2021

Hard turning has gained substantial response in metal machining since it has substituted the cycl... more Hard turning has gained substantial response in metal machining since it has substituted the cycle of traditional process i.e. turning, heat treatment and finish grinding associated with hard parts. This current research goals at evolving an electrorheological fluid damper for reducing vibrations of tools and endorsing improved machining results during hard turning. The ER fluid performs like a spring having nonlinear vibration features tackled by configuration of ER fluid, the electric parameters of electric field and the shape of plunger. Turning investigations are conducted to attain a set of electrical compositional and shape constraints which will reduce tool vibrations and endorse improved cutting performance throughout turning of steel EN24 of 49 HRC with minimum fluid application. It is perceived that utilization of ER fluid damper decreases tool vibrations and increases turning performance efficiently. If this awareness gets commercialize it will beneficial for machining industries.

Polymer Bulletin, 2020

This work addresses a facile and broadly applicable method of fabricating a new thermoplastic sha... more This work addresses a facile and broadly applicable method of fabricating a new thermoplastic shape memory polymer (SMP) composite by blending three biopolymers such as polyvinyl alcohol, polyvinyl pyrrolidone and polyethylene glycol. Reduced Graphene (rGO) is used as electrical conductive fillers. Iron Oxide (Fe 3 O 4) and rGO-Fe 3 O 4 combination provides thermo-electric stimulus. Under the thermal stimulus, shape recovery rate of the SMP with hybrid fillers was faster, having quick response time (28 s) compared to electrical stimulus response time (75 s). The conductivity of the SMP matrices increased by 7, 10 and 15 orders of magnitude by incorporating Fe 3 O 4 , rGO and rGO-Fe 3 O 4 fillers, respectively. Moreover, the proposed shape memory polymer containing rGO-Fe 3 O 4 filler exhibits a higher Young's modulus (> 80%) compared to neat polymer (1.75 GPa at room temperature and 0.6 GPa at glass transition temperature, Tg). A maximum stress of 2.5 MPa and 4% recoverable strain was achieved in the SMP with 10 and 15 wt% of hybrid fillers and interestingly no stored strain evolves, upon cooling below T g. The developed SMP may be applied in morphing wing and other smart actuator applications.

International Journal for Multiscale Computational Engineering, 2020

Materials Today: Proceedings, 2020

Carbon, Graphite and Diamond are the three forms. Carbon and Graphite are having good conducting ... more Carbon, Graphite and Diamond are the three forms. Carbon and Graphite are having good conducting properties. Graphene is also a form of graphite and many synthesis methods like mechanical exfoliation, chemical exfoliation, chemical synthesis; Chemical vapor deposition and many more are existing. Experiments to synthesize graphene through electrochemical exfoliation method are used. It gives the comparison of results of the samples when supplied with 5 V and 10 V separately. Also Emissions of the castor oil are also tested. It is found that 10 V sample exhibits good results compared to others.

Materials Today: Proceedings, 2019

Constitutive modelling of shape memory alloys with new material functions is presented within the... more Constitutive modelling of shape memory alloys with new material functions is presented within the frame work of thermodynamic consistency. A one-dimensional constitutive model based on the previous work of constant and non-constant material functions is redefined from first principles. In the first step Clausius-Duhem inequality condition for stress is rewritten and an alternate form of differential equation is proposed. The initial and final condition of evolution are applied to obtain a new form of non-constant transformation tensor, which is independent of residual strain the SMA material. As a result in the present work the residual strain is purely defined as a function of transformation stress and not as a function of transformation modulus. The proposed form of new transformation tensor is compared with previously proposed material function and validation results for the consistency are presented. It is observed that newly derived non-constant material function is compatible in both differential and integrated form of the one-dimensional shape memory alloy constitutive relation and satisfies the evolution conditions of phase transformations.

International Journal for Multiscale Computational Engineering, 2019

Composites Part B: Engineering, 2018

In the present work Eshelby's equivalent inclusion method is extended to compute the effective pr... more In the present work Eshelby's equivalent inclusion method is extended to compute the effective properties of two inclusions in a heterogeneous matrix. Generally Eshelby's problem involves a single inclusion under dilute distribution in two phase composites. Moreover, unlike the dual inclusion theory, which is based on the concept of one inclusion embedded in to the second inclusion, alternate problem is now addressed. In this paper Eshelby's single equivalent inclusion concept is extended to the case of composite consisting of two different inclusions embedded separately in a heterogeneous matrix. In the composite, first inclusion is fibre and second inclusion is carbon nanotube embedded in a shape memory polymer heterogeneous matrix. The solution is obtained through individual eigenstrains in both the inclusions. The general closed form relations for the effective moduli and inelastic strain tensors are derived under infinitesimal strains of constituent materials following a two-step homogenization procedure. Analytical solutions of Eshelby's problem with two cylindrical inclusions explicit of each other, having different properties and placed in the same inelastic matrix domain are obtained. The relations are then applied to characterise the shape memory polymer composite. The consistency of the novel relations are established by comparing the results with other micromechanics methods.

Smart Structures and Systems, 2017

Nanocomposites reinforced with carbon nanotube fibers exhibit greater stiffness, strength and dam... more Nanocomposites reinforced with carbon nanotube fibers exhibit greater stiffness, strength and damping properties in comparison to conventional composites reinforced with carbon/glass fibers. Consequently, most of the nanocomposite research is focused in understanding the dynamic characteristics, which are highly useful in applications such as vibration control and energy harvesting. It has been observed that those nanocomposites show better stiffness when the geometry of nanotubes is straight as compared to curvilinear although nanotube agglomeration may exist. In this work the damping behavior of the nanocomposite is characterized in terms of loss factor under the presence of nanotube agglomerations. A micro stick-slip damping model is used to compute the damping properties of the nanocomposites with multiwall carbon nanotubes. The present formulation considers the slippage between the interface of the matrix and the nanotubes as well as the slippage between the interlayers in the nanotubes. The nanotube agglomerations model is also presented. Results are computed based on the loss factor expressed in terms of strain amplitude and nanotube agglomerations. The results show that although - among the various factors such as the material properties (moduli of nanotubes and polymer matrix) and the geometric properties (number of nanotubes, volume fraction of nanotubes, and critical interfacial shear stresses), the agglomeration of nanotubes significantly influences the damping properties of the nanocomposites. Therefore the full potential of nanocomposites to be used for damping applications needs to be analyzed under the influence of nanotube agglomerations

The present work investigates the micromechanics approaches to model the thermomechanical behavio... more The present work investigates the micromechanics approaches to model the thermomechanical behaviours of shape memory alloy composites. The research is primarily focussed on modelling the pseudoelastic and shape memory behaviours of smart composites, which are inherent in multifunctional materials like shape memory alloys and polymers. In the study, non-adaptive and adaptive matrix materials are used to address the adaptive fibre non-adaptive matrix, and adaptive fibre adaptive matrix concepts, respectively. Nickel-Titanium shape memory alloy wire is used as an adaptive shape memory fibre. Similarly, epoxy matrix that does not exhibit shape memory behaviours is considered as non-adaptive, while matrix possessing such behaviours has been employed as an adaptive matrix. The importance of the present research is to develop the modelling procedures for shape memory composites useful in high performance applications. The first and the foremost requirements are to propose the constitutive relations, which should be simpler in computation and at the same time address the fundamental mechanics of constituent materials. Therefore, simple analytical approaches are streamlined and the exist Chetan S. Jarali Dr. Chetan S. Jarali received the Ph.D. degree in Mechanical Engineering from Visvesvaray Technological University, Belgaum, India in 2012. The Ph.D. was carried out at CSIR National Aerospace Laboratories, Bangalore, India. His research interests involve Smart Materials, Composites, Fatigue,Damage, and Health Monitoring of Adaptive Structures.