Mechanical Deparment

Energy harvesters that extract energy from vibrating system with the help of piezoelectric cantilever beam show strong potential for powering wireless devices. This paper presents numerical characterization of piezoelectric cantilever beam having rectangular cross-section to enhance the power of energy harvesters. The beam was modeled based upon Euler Bernoulli's beam theory. In this work, piezoelectric cantilever beam with 31 effects was developed to analyze the dynamic behavior of this system with the help of finite element method. It was noticed that the highest tip displacement of cantilever beam was in the second mode at 25 mm length. It was further indicated that second mode of resonant frequency provided higher voltage as compared to first mode of cantilever beam without any proof mass. But when proof mass was added at free end the voltage dropped in the second mode and increased in first mode under a proof mass of 0.40 g.

This research work investigates the energy absorption, and damage tolerance behavior of three phased (carbon woven/epoxy/ multiwall carbon nanotubes) polymer composites. Five doping weight fractions of multi-wall carbon nanotubes (MWCNTs) are considered as 0, 1, 2, 3 and 4 wt.% of thermosetting epoxy resins. Low-velocity impact (LVI) tests are conducted on drop tower setup with three different velocities, 3.5, 4.5 and 5.5 m/s. Damage caused by a 10 kg, hemispherical headed cylindrical impactor is analyzed and compared. The experimental results showed an increase in the energy absorption up to 3 wt.% of the MWCNT doping. However, reinforcing above this percentage, the energy absorption is reduced due to the formation of MWCNT agglomerations. Therefore, this work proposed an optimized doping percentage for CFRP laminates. The maximum improvement of 51.83% in energy absorption was found at 3 wt.% of MWCNT reinforcement in epoxy resins.

In this research work, the effect of Xenon poisoning in a Canadian Deuterium Uranium (CANDU) reactor for different load cycles has been examined. The three load cycles that have been analyzed are 100%-70% full power, 100%-60% Full Power (FP), and 100%-50% FP. It is considered that the CANDU reactor has operated for a full week on a particular load cycle and the maximum excess of Xenon reactivity that accumulated in the reactor during the load cycle has been estimated. After calculating the excess Xenon reactivity in a load cycle, it has been analyzed whether it is within given reactivity limit (-18 to +7 mk) provided by devices which include liquid zone controllers, absorbers and adjusters in a CANDU reactor. Further it has been also mentioned as to what are options of controlling the reactor power if this excess reactivity exceeds the limit supplied by adjusters, absorbers and liquid zone controllers. With the results of the mathematical analysis of Xenon and Iodine concentration the optimized load cycle on which the CANDU reactor should be operated has been estimated. The impact of all the three power cycles on the uranium fuel is also studied.

During LVI in fiber/epoxy composites, the dominant damage mechanisms are: matrix cracking (crack generation), delaminating (interface failure) and fiber fracture [18]. Matrix modification using MWCNTs provides better load transfer [19] and improved

Present work deals with the numerical investigation of a cantilever beam having I cross section made up of piezoelectric material for its actuation capability. The beam is modeled under the assumption of Euler's Bernoulli equation. Eight cases are considered for different electrode locations. The beam was subjected to voltage loads at different locations. It was noticed that tip deflection increases with increasing applied voltage across the electrodes. Maximum tip deflection was achieved with the increase in voltage with particular electrode arrangement. In this report we have also demonstrated that for downward tip deflection, there are two values of thickness ratio of flange and web for a given tip deflection at a given applied voltage.

Digital Twin-based Cyber-Physical Quality System (DT-CPQS) concept involves automated quality checking, simulation, and prediction of manufacturing operations to improve production efficiency and flexibility as part of Industrie4.0 initiatives. DT-CPQS will provide the basis for the manufacturing process to march towards an autonomous quality platform for zero defect manufacturing in the future. Analysing sensor data from the CNC machine and vision monitoring system it was concluded that there was enough signal data to detect quality issues in a part being machined in advance using statistical/mathematical models (Smart PLS) and using machine learning algorithms. This allows the operator to take corrective actions before the resultant part ends in a quality failure and reduces the inspection time. The proposed approach forms the basis in expanding this concept to a large machine shop wherein by monitoring various parameters of the machines and state variables of the tools we can detect quality issues and develop an automated quality system using machine learning techniques.

In this paper, we propose a Cyber-Physical Quality System (CPQS) integrated framework that can predict, analyze, and
validate the quality monitoring system in manufacturing with 95% accuracy in real-time using machine learning techniques.
CPQS framework analyses real-time sensor networks and configures the importance of artificial intelligence-driven big data
analytics for predicting the quality of cyber-physical production networks. Cyber-physical data like speed, feed, depth of cut,
coolant temperature, vibrations, tangential cutting forces, and tool life for 400 parts were collected from the various sensors placed on Computerized Numerical CNC) machines after doing modal analysis.  Various machine learning techniques were used to predict the quality of the part wherein the inputs affecting it were predominately dominated by
vibration and temperature. Extreme Gradient Boosting (XGB) machine learning techniques out of many could predict the quality of the part with
96.2%. accuracy. The caveat for the present results is that it has been tried out only for Titanium Alloy parts and the tool wear has been approximated using Taylor’s equation which can be enhanced by using image processing. The model deployed in real-time could produce defect-free parts quickly. This could reduce the cost of quality by 80%, thereby increasing the production line's productivity, quality, and efficiency.

Digital Twin-based Cyber-Physical Quality System (DT-CPQS) concept involves automated quality checking, simulation, and prediction of manufacturing operations to improve production efficiency and flexibility as part of Industrie4.0 initiatives. DT-CPQS will provide the basis for the manufacturing process to march towards an autonomous quality platform for zero defect manufacturing in the future. Analysing sensor data from the CNC machine and vision monitoring system it was concluded that there was enough signal data to detect quality issues in a part being machined in advance using statistical/mathematical models (Smart PLS) and using machine learning algorithms. This allows the operator to take corrective actions before the resultant part ends in a quality failure and reduces the inspection time. The proposed approach forms the basis in expanding this concept to a large machine shop wherein by monitoring various parameters of the machines and state variables of the tools we can detect quality issues and develop an automated quality system using machine learning techniques.

In this paper, a dielectric barrier discharge plasma based atmospheric pressure plasma jet has been generated in a floating helix and floating end ring electrode configuration using argon and helium gases. This configuration is subjected to a range of supply frequencies (10-25 kHz) and supply voltages (2-6 kV) at a fixed rate of gas flow rate (i.e., 1 l/min). The electrical characterization of the plasma jet has been carried out using a high voltage probe and current transformer. The current-voltage characteristics have been analyzed, and the consumed power has been estimated at different applied combinations for optimum power consumption at maximum jet length. The obtained optimum power and jet length for argon and helium gases are 12 mW and 32 mm, and 7.7 mW and 42 mm, respectively. It is inferred that besides the electrode configurations, the discharge gas is also playing a significant role in the low power operation of the cold plasma jet at maximum jet length. The obtained results are interpreted on the basis of penning processes.

In this study, an atmospheric pressure cold plasma jet has been generated based on dielectric barrier discharge plasma. The double ring electrode configuration is used and analysis has been performed subjected to wide range of supply frequencies up to 25 kHz and supply voltage up to 6 kV. The electrical characterization of the plasma jet has been carried out using a high voltage probe. The V-I characteristics of the developed cold plasma jet have been studied and the consumption of the power has been analyzed at various input combinations of supply frequency and applied voltage. Consequently, the supply voltage and supply frequency are optimized with respect to the discharge current and jet length for optimum power consumption. The peak power consumed for glow discharge operation has been found to be 1.27 W in the optimized configuration.

In this paper, a dielectric barrier discharge plasma based atmospheric pressure plasma jet has been generated in a floating helix and floating end ring electrode configuration using mixture of argon and nitrogen gases (50:50 ratio). This configuration is subjected to a range of supply frequencies (10–25 kHz) and supply voltages (6.5–9.5 kV) at a fixed rate of gas flow rate (i.e., 1 l/min). The electrical characterization of the plasma jet has been carried out using a high voltage probe and current transformer. The current–voltage characteristics have been analyzed, and the power consumed by the device has been estimated at different applied combinations of supply frequency and voltages for optimum power consumption and maximum jet length. A comparative analysis of the results of the above experiments has shown that maximum power consumed by the device in helix electrode configuration with end ring is 19 W for (Ar+N2) mixture as compared to only 12 mW and 7.7 mW for Ar and He gas res...

In this study, an atmospheric pressure dielectric barrier discharge-based argon plasma jet has been modeled using COMSOL Multiphysics, which is based on the finite element method. The fluid dynamics and plasma modules of COMSOL Multiphysics code have been used for the modeling of the plasma jet. The plasma parameters, such as electron density, electron temperature, and electrical potential, have been examined by varying the electrical parameters, that is, supply voltage and supply frequency for both cases of static and with the flow of argon gas. The argon gas flow rate was fixed at 1 l/min. Ring electrode arrangement is subjected to a range of supply frequencies (10–25 kHz) and supply voltages (3.5–6 kV). The experimental results of the ring electrode configuration have been compared with the simulation analysis results. These results help in establishing an optimized operating range of the dielectric barrier discharge-based cold plasma jet in the glow discharge regime without arci...

Content Atmospheric pressure glow discharges (APGD) based on dielectric barrier discharge (DBD) offer the prospect of a future basic technolo8 for low-tcmperature proccssing of gaseous and solid materials without the use of a vacuum chaiuber 1}. DBD based atmospheric preveure plasma jets (APPJ’s) have wide range of potential applications such as thin film deposition |2J, sterilization |3], surface modification 4-5) , and etching |GJ . Important properties of this type of plasma are that it operates near room temperature, allows treatment of irregular surfaces and has a small penetration depth 7) . A floating helix electrode configuration 8] was implemented for generation of atmospheric pressure DBD based cold plasma jet using Ar/He gas. In this paper, floating helix electrode configuration has been used to genei-ate atmospheric pressure DBD based cold plasma jet using a mixture of argon and nitrogen gas. It was subjected to a range of supply frequencies (10-25 kHz) and supply voltag...

Power generation in a nuclear plant is dependent on the Nuclear steam supply system (thermal energy source), the turbine generator (energy conversion), the circulating water system (heat rejection) and condensate/feed water system (regenerative heat and recycle of working fluid) and the plant electric system supporting these. These power generation processes must be operated so as to maintain energy and mass balance under changing conditions of load and environment. Grid electrical disturbances cause significant deviations in grid supply voltage and frequency. The abnormal conditions that accompany the imposition of grid electrical disturbances on a nuclear plant can disrupt the dynamic state of process systems equilibrium. The impact of grid electrical disturbances are in two different ways viz. (i) process degradation and (ii) impact on electrical components. Analysis of both these aspects are required to be carried out to design efficient reactor system high plant availability. I...

Abstract- Power generation in a nuclear plant is dependent on the Nuclear steam supply system (thermal energy source), the turbine generator (energy conversion), the circulating water system (heat rejection) and condensate/feed water system (regenerative heat and recycle of working fluid) and the plant electric system supporting these. These power generation processes must be operated so as to maintain energy and mass balance under changing conditions of load and environment. Grid electrical disturbances cause significant deviations in grid supply voltage and frequency. The abnormal conditions that accompany the imposition of grid electrical disturbances on a nuclear plant can disrupt the dynamic state of process systems equilibrium. The impact of grid electrical disturbances are in two different ways viz. (i) process degradation and (ii) impact on electrical components. Analysis of both these aspects are required to be carried out to design efficient reactor system high plant avail...

In the present work, vibration control of a simply supported plate with line type and cross type piezoelectric (PZT) patches are investigated with and without actuation voltage. The plate is modeled under the assumption of Kirchhoff’s Plate theory. The mass of PZT patches remain constant in all cases. In case of actuation, applied voltage considered are 1, 2 and 3 mV. The external excitation to the plate is in the form of harmonically varying point load of 1 mN. It is noticed that cross type PZT patch is more effective in deflection suppression of plate than that of line type PZT patch at 3 mV of actuation at patch thickness of 0.75 μm. Suppression of central deflection of plate for line type and cross type PZT patches are obtained in different frequency bands of (175–185 Hz) and (870–880 Hz) respectively.