Renewable energy is currently a great alternative for humans in many applications such as industrial production, heating, and transportation.One of the fastest developing technologies nowadays is electric vehicles, small-size mobile robots powered by renewable energy.This study presented the design, optimization, and implementation of a prototype of a solar-powered mobile robot (SMR) applied for transportation.The SMR was optimized by multi-constraints such as small dimension, small weight, and low power consumption.In the scope of green energy collection, the SMR is capable of fast charging time and high energy storage capability by the use of arrays of supercapacitors which are the current trend in robotics power management.The SMR was powered purely by solar energy and controlled via Wi-Fi protocol using a low-powered consumption IoT solution.The SMR had been tested for carrying a weight of 4.1 kg and traveled a 10-meter path in each testing cycle.Within 15 minutes, the SMR had completed 26 cycles with a total distance of 260 meters and the total transported weight was 103 kilograms which was nearly 50 times larger than the weight of itself.The SMR has shown a high potential to be applied in many fields such as food delivery, package transportation in warehouses, infrastructure buildings, and agriculture.
Today, microchannels are widely used in various fields, leading to the need for different and new requirements for microchannels during practical applications in terms of operating conditions, working fluids, and structure.Micro-channels exhibit remarkable heat transfer properties, enabling them to efficiently dissipate extremely high heat fluxes within confined spaces.The generation of large quantities of heat within a compact area in optical and electronic devices has led to advancements in microelectromechanical systems (MEMS).Microchannel heat sinks (MCHS) have been introduced to absorb high heat fluxes, which enables these devices to perform properly.This study aims to examine how an advanced ultra-high-temperature ceramic material, Hafnium diboride (HfB2), responds to normal heat flux conditions.The finite element approach was used to solve the governing equations for the solid (HfB2) and liquid (water) domains.The primary factors contributing to the elevated rate of heat transfer are that HfB2 is a good thermal conductor and that each microchannel volume has a large amount of heat transfer surface area.HfB2 exhibits intriguing thermal characteristics and possesses high-strength properties as an ultrahigh-temperature ceramic.The numerical analysis of a microchannel heat sink with extremely high heat flux, constructed using HfB2, is conducted using the finite element method.At the exceptionally high heat flux of 3.6 MW/m 2 , the maximum temperature of the wall was determined to be 360 K.
The advances of additive manufacturing by a 3D printing method such as complex geometry building, time-consuming, worker labor, and materials cost, support this new type of construction method to become promising for future applications.This study presents the development of a customized and large-size concrete 3D printer with low cost, ease of operation, and scalable design.The 3D printer gantry-type structure was designed with a dimension of 2,580 x 3,600 x 2,800 (mm) and driven by high-precision AC motors in three independent X, Y, and Z axes.A customized feeding-extrusion system was designed for either automatic or manual material feeding continuously and automatically.The low-cost concrete mixture was used with the use of by-products from a local thermal power plant which allows to reduce the material cost.After a number of experimental trials, an optimized set of parameters has been established such that a printing cycle of 25 layers was printed consecutively at a single run.Several concrete-based construction patterns have been printed and applied in practice.The results can be applied in many aspects of civil construction and produce affordable buildings worldwide.
The current study focuses on investigating the mechanical properties of joining two dissimilar pieces of Austenitic stainless steel AISI304 and Low carbon steel ST-37 using rotary friction welding techniques.The metals were welded under different rotational speeds 560,1030 and 1800(RPM) using three forging pressures 45, 65, 80(MPa), under variable friction times at each rotational speed.The tensile test, impact test, microhardness distribution and microstructure examination of the welded specimen were carried out.It was noticed that it is possible to reach the ideal welding parameters with applicable mechanical properties at each rotational speed.The tensile strength increased when the forging pressure increased.The maximum tensile strength was 594(Mpa) achieved at a rotational speed of 560(RPM) with joint efficiency 93.5%.The greatest hardness of the welded parts was achieved in the welding interface of all samples and then gradually decreased towards the adjacent area of the welding zone.The hardness increases with increasing rotational speed, or forging pressure.The impact energy decreased when the forging pressure increased, and the maximum impact of energy value 122(J) were available at rotational speed 1030 (RPM) with joint efficiency 97.6%.
Accurately estimating tire forces is crucial for understanding and optimizing vehicle dynamics, particularly in terms of handling and stability.This paper presents a novel approach for estimating tire forces using a multi-layer perceptron (MLP) neural network and emphasizes the significance of carefully selecting the network architecture and training method for achieving optimal performance.The proposed method involves training the MLP neural network using an extensive and diverse dataset encompassing tire force measurements and associated input variables.This comprehensive dataset enables the network to capture and model the intricate and non-linear relationships that exist between input variables and tire forces.Through this process, the network becomes adept at providing accurate and real-time estimations of tire forces, which is essential for understanding and optimizing vehicle dynamics.Additionally, the paper explores the utilization of the Levenberg-Marquardt (LM) algorithm to optimize and fine-tune the weights and biases of the MLP network during the training process.Based on proposed method, a neural network is designed and trained to predict the lateral force of a tire based on the tire's slip angle and longitudinal force.The results of our research demonstrate the superior accuracy achieved by our proposed method in predicting tire forces across a range of scenarios and conditions and explore the effects of different factors which are involved in this study.This could contribute to advancements in traction control, stability control systems, and overall vehicle maneuverability.
The primary source of power in many situations, including backup power, emergencies, isolated locations, construction, etc., is an internal combustion engine.These have higher engine emissions, which is a major drawback.Low temperature combustion engines may prove to be the best option in this case, because they not only produce power with high efficiency but also produce fewer engine emissions.It was investigated how a reactivity-controlled compression ignition engine that runs on liquid petroleum gas performs and produces emissions.The pilot fuel i.e., diesel was directly injected during the compression stroke into the engine cylinder, whereas the main fuel, liquified petroleum gas, was injected during suction stroke into the inlet port via mechanical injection system.At the engine's inlet port, an electronic port injector was mounted.The engine's experimental testing was conducted at a fixed 1500 rotation per minute controlled with the help of governor.The maximum rated power output of the engine was 3.7 kW.The ratio of premixed energy is taken at 95%.Experiments were first carried out on a normal diesel combustion engine before being switched to the reactivity controlled compression ignition (RCCI) engine.The experimental results demonstrate the brake specific fuel consumption (BSFC) and brake power (BP) is reduced up to 83.14% and by 34.65% respectively.The rise in cooling water temperature is reduced by 15.38% and 5.88% at 0% and 100% loading conditions respectively.The exhaust gas temperature is reduced by up to 29.77%.Brake thermal efficiency increased by 19.17%.Smoke opacity is reduced by 81.29% and 69.81% at 0% and 100% loading condition respectively, as compared to the normal diesel combustion engine.According to the findings, a reactivity controlled compression engine may operate efficiently using liquified petroleum gas that contains approximately 95% premixed energy.As a result, there will be less demand for diesel fuel and engine emissions.
Vibrations are present in all types of vehicles and are very important for comfort and safety during travel.In this work, based on random road profiles obtained from the ISO 8608 standard of 2016, power spectral density (PSD) functions are obtained in terms of displacement and acceleration.Therewith, a methodology to obtain the variance and rms acceleration of the sprung mass is described.In sequence, it is proposed an ideal suspension design methodology that employs a multi-objective optimization technique based on Non-dominated Sorting Genetic Algorithm II (NSGA-II).In the computational implementation, the design criterion is defined as the minimization of the sprung mass vertical variance displacement, as well as the vertical rms acceleration of the sprung mass.Using a quarter car model, the damping and stiffness of the sprung mass are defined as design vectors.As a result, the NSGA II algorithm provides the Pareto front whose numerical values correspond to a set of feasible designs.Comparisons of the results with some methodologies described in the literature are made.The methodology proposed here leads to a decrease in the vibration amplitudes both in the frequency and time domains.
Of the many vital parts of an automobile, the wheels play a pivotal role.The rim is the exterior edge of a wheel, which grips the tire.It forms the outside portion of the wheel upon which the inner portion of the tire gets attached as seen in automobiles.It is important to predict the failure of any machine element during the design phase itself.This ensures the safety of the product while in service.Finite Element Method is one such method which aids in achieving this objective.There are a number of softwares which are used for modelling a machine part.However, the analysis is generally carried out using a software like ANSYS.Fatigue analysis is critical in components subjected to fluctuating load cycles.This paper presents modelling of the wheel rim covering all the major parts and performing the fatigue analysis.The modelling was done using CATIA V5 and the fatigue analysis was performed using ANSYS WORKBENCH.The fatigue analysis results indicated that the life cycles and safety factor achieved for both the designs were the same and are in compromise with the theoretically obtained results.However, the second design exhibited noticeable enhancement in the deformation and equivalent stress (Von-Mises stress) values.
Today, the transportation sector is mainly dependent on internal combustion engines.The total number of vehicles running on the road has reached 1.2 billion.The transportation sector is responsible for a 23% share of greenhouse gas emissions.As a result, researchers and governments are debating the future of the transportation sector.The main factors driving the discussion and development of alternatives for internal combustion engines are air pollution caused by transportation, energy security concerns, rising hydrocarbon fuel prices, climate change issues, the desire to develop economic infrastructure in rural areas by promoting biofuels and bio-waste management, and the desire to lead the world in new technology development.Currently, four types of configurations are in use: internal combustion engines, battery electric vehicles, fuel cell vehicles, and hybrid vehicles.The major advantages, disadvantages, problems, future, cost, emissions produced, environmental impact, fuel and material availability, efficiency, etc., of all these available options for transportation are presented in this paper.The results of this study show that there are a number of alternatives emerging for transportation, but internal combustion engines will still remain as the primary source for transportation for the coming decades.
Purpose This research proposes a multi-input multi-output (MIMO) model, based on a data-driven approach, to assess passenger vibration comfort on rail vehicles.The MIMO model represents the mathematical relationship between input and output variables that contains modal properties and vibration transmission.An optimization algorithm estimates the frequency response functions at the interface seatpassenger of the trains.Methods The MIMO model evaluated the frequency response functions along x-, y-and z-axis.Multivariate analysis considered the calculation of the partial coherence functions, the cross-correlation functions, and the Anderson-Darling nonparametric test.Results This research considered the acceleration measurements on two Trains, one Tramway, and one Underground.This research developed accelerations analyses in the time domain; the transmissibility of accelerations in the frequency domain.The measuring points were on the seat base and the interface seat-passenger of the trains.The frequency response data, obtained experimentally according to x-y-and z-axis, generated a multi-input and multi-output frequency response model.This research is based on experimental investigations and statistical tests.The calculation of partial coherence evaluated the percentage of spectrum output due to a specific (conditional) input.The partial coherences assess the energy contribution of each input to the output.The cross-correlation test showed the phase between input and output accelerations.The Anderson-Darling test showed the provenance of the data sample from a population with a specific distribution.Anderson-Darling's nonparametric test attaches weight to tails.Conclusions The seats of the trains were exposed to complex vibrations according to the three directions x, y, and z.The three inputs are linear accelerations along the vertical, lateral, and forward direction of the seat base.If the accelerations on the seat base represented the inputs to the MIMO model, the accelerations acquired at the passenger-seat interface represented the output of the MIMO model.
The search for engineering materials for light weight applications, material conservation, and cost effectiveness necessitated the development of new materials.However, the properties of these materials need to be investigated to ascertain its suitability in its application.Hence, the engineering students need to understand the behaviour of these materials and the methods of investigation.This paper presents the development of a piece of simple laboratory equipment for determining the flexural strength of light materials for student practicals.The development process involves the design and construction of the equipment for carrying out 3-point test on a given specimen.The equipment has various components, such as the pivots, force gauge, gauge holder, rack and pinion gear, hand lever and the frame.The graphics design and simulation were done with solidworks software, version 10.The materials used for the production of these components were selected in line with material selection guidelines and also according to the mathematical designed parameters.The selected materials were locally sourced for cost effectiveness.The construction processes involve basic engineering process like cutting, filling, drilling, welding and surface finishing, at the total cost of 125 USD.After construction, the equipment was used to perform a 3-point test on three different materials (Perspex, Plywood and Particle Board), and flexural strengths of 86.3MPa, 26.62MPa and 21.96MPa respectively were obtained.The equipment is recommended for testing a low ductile material requiring a maximum flexural force of 500N and maximum deflection of 0.1m.Hence, it can be used in high colleges for the study of strength of materials.
Grey relational analysis is a widely used approach for the purposes of decision making, prediction and relational investigation.This study utilizes the grey relational analysis for modelling surface roughness during the single point diamond turning of RSA-443.The utilized parameter in this study is the grey relational grade together with cutting speed, feed, and depth of cut.The Taguchi L9 orthogonal array has been utilized for designing the experiment, with three extra experimental runs being carried out for the purposes of validating the developed model.The developed model indicates that the cutting parameters are insignificant as predictors of surface roughness.Grey relational grade is the only significant predictor of surface roughness.Acoustic emission signal root mean square has been used for determining the grey relational grade in the study.The grey relational analysis-based surface roughness values have been compared to experimentally obtained values by using the Mean Absolute Percentage Error (MAPE).The accuracy levels are an exhibition of high prediction power of the model.Pair t-test results indicate the lack of statistical significance in the difference between the experimentally measured and predicted surface roughness values.
Machining Rapidly Solidified aluminium (RSA) 6061, a widely used optical material by Ultra-high precision diamond turning, has enabled high accuracy and surface integrity.However, improved quality and productivity require precision surface and machining process monitoring because the duo has a great influence on machine part performance.The study presented in this paper investigates the effects of cutting parameters (i.e., depth of cut, feed rate and cutting speed) on machining output variables (surface roughness and acoustic emission potentials) during ultra-high precision diamond turning of RSA 6061.With the aid of Box-Behnken design (BBD), a response surface methodology, and the analysis of variance (ANOVA), the correlation between cutting parameters and machining output variables were analyzed and modeled.The results showed that both surface roughness and acoustic emission potentials are greatly influenced by feed rate and cutting speed.For a better-quality surface roughness and low acoustic emission during ultra-high precision diamond turning of RSA 6061, high cutting speed and low feed rates are the right combinations and vice versa.
Computer modeling and numerical simulation has become an efficient diagnostic tool to predict the human body injuries caused due to high speed automotive impacts, blast and ballistic impacts.Soft tissues such as muscles and skin in human body are exposed to varying strain rates under dynamic loadings during impacts.The prediction of impact-induced injuries requires a thorough understanding of mechanical behaviour of soft tissues for computational modeling of human body.In the present study, uniaxial tensile tests were conducted on caprine lower extremity muscles in the strain rate range of (500s -1 -3500s -1 ) using custom-made split Hopkinson pressure bar (SHPB) apparatus.The challenges in the dynamic testing of soft tissues such as measurement of weak transmitted signals, use of viscoelastic pressure bars, tensile loading of specimen and generation of constant strain rate were addressed in dynamic tensile testing of soft tissues using polymeric SHPB.The attenuation and dispersion in waves are corrected using isolated incident bar tests.The stress-strain results were determined from the reconstructed waves for the tests conducted on lower extremity caprine muscles.The muscle specimens were tested along and perpendicular to the fiber direction to study the directional dependency of tissue behaviour.The stress-strain response was found to be non-linear and significant dependant on strain rate when tested along and perpendicular to fiber direction at same strain rates.It is also observed that at the same strain rate, the specimen stress of caprine muscle along the perpendicular fiber direction is higher than that along the fiber direction.The obtained results may further be used to develop finite element human body models and safety systems for human body in high rate scenario.
Machine tool is an important role in the industry because the mechanical components or products are manufactured by machine tools. The machine tools are assembled by components. The surface between two components is the combined or contact surface. Different bolt locking sequences will affect the combined surface in the machine tool. In this study, the SolidWorks software is used to create the CAD model. The finite element simulation is used the ANSYS software to simulate the influence of bolt locking methods on the combined surface of column structure and guideway and the fillet radius design on the deformation of anchor bolts. From the simulation results, the minimum deformation of the column is observed in the locking sequence from middle to both sides. The stress distribution of the combined surface is slightly difference of three locking methods. The simulation results of the guideway show that the minimum displacement of combined surface is obtained by using locking sequence from outside to the middle. The maximum displacement is obtained locking sequence from right to the left order. From the simulation results of anchor bolt, increasing the fillet radius of anchor bolt decreases the deformation of anchor bolts. The deformation of anchor bolts drastically decreases with increasing the fillet radius from R8 to R60. The simulation models and results provide the reference for the bolt locking sequence and anchor bolt fillet radius design.
A nozzle is equipped for changing, transforming pressure energy into kinetic energy and the other way around, depending on the state of the nozzle above changes happen. Nozzle which is a C-D nozzle is utilized to achieve supersonic stream speeds. The inlet Mach number is less than one; the convergent section speeds up it to the sonic speed at the throat and further sped up to supersonic speeds by the diverging section. A nozzle is a device intended to control the direction or attributes of a fluid flow (particularly to expand speed) as it exits (or enters) an encased pipe. A nozzle is frequently a channel or container of shifting cross-sectional zone and it very well may coordinate or change the progression of a liquid (gas). Nozzles are as often as possible used to control the speed of stream, speed, and direction, mass, shape, and/or the pressure of the stream that emerges from them. To improve the mixing attributes execution of supersonic controlled stream using limiting tab, which is the dainty wire that makes 5% obstruction of the diameter across of the nozzle exit. Different Reynolds Averaged Navier Strokes EquationRANS models are using and look at the consequences of Mach no.1.86 supersonic stream from 2D Convergent-Divergent nozzles for NPR 4 with a step size of one, to examine diverse scientific models for execution.Converging the over-expanded and close to addressing development condition ANSYS Fluent 16.0.Using 2D hex components and organized work has produced into the ICEM module.Non-dimensional plots of Mach No along fly focus line, regarding the non-dimensional separation of k-ε workable, k-ω, k-ω standard, Reynolds Stress with standard and change SST conditions are looked at and investigations.
Titanium aluminides have become the preferred titanium-based alloys for high temperature applications due to their resistance to oxidation at elevated temperatures. However, the inherent limitations of the conventional methods of manufacturing have adverse effects on the mechanical properties of the alloy and limit its applications. The current study focused on determining the optimum process parameters that could be used to produce a Ti6Al alloy with required microstructural properties and complex geometrical configurations using the direct metal laser sintering method. Single tracks were produced at laser powers of 150 W and 350 W over a wide range of scanning speeds. Continuous tracks were achieved only at a laser power of 150 W at corresponding scanning speeds of 1.0 m/s to 1.4 m/s. A cross sectional analysis was conducted on the single tracks and 1.2 m/s emerged as the optimum scanning speed. 3D objects were manufactured at optimum process parameters of 150 W, 1.2 m/s and a hatch distance of 80 µm. The microstructure of the 3D objects was homogenous which attests that the direct metal laser sintering method could be used to produce Ti6Al parts with the desired mechanical properties and geometrical complexity.
Machine tools are assembled by thousands of components.The surface between two components is the mating surface.The bolt tightening methods will affect the stress and deformation of mating surface which influences the accuracy and rigidity of machine tools.In the precision machinery industry, if the structure needs to tighten in line such as linear guideway, the senior engineers will tighten the bolts from sides to the middle or middle to sides instead of tightening in order.Furthermore, engineers use two-step of tightening rather than one-step of tightening.Based on their experience, these tightening methods will reduce the stress of mating surface and increase the rigidity of entire structure.In this study, the three bolts tightening model is used to investigate these tightening methods.Three bolts tightening CAD model is created by using the SolidWorks software.The finite element analysis is used the ANSYS workbench R19 software to simulate the bolt tightening methods (tightening sequences and pre-tightening force ratio) on the mating surface and entire model.From the simulation results, the minimum stress is observed in the tightening sequence from sides to middle and maximum stress is obtained in the tightening sequence in order.The experimental results of bolt tightening sequences match the simulation results.The stresses of mating surface and entire model drastically decrease when the tightening step is two-step of tightening.In two-step tightening process, the pre-tightening force ratio 1:1 is the optimal tightening methods for reducing the stress of mating surface compared to another pre-tightening force ratio.
