Wear and Corrosion Resistance of Hardened Fe-Al-Mn Grinding Ball

Objective: This study aimed to determine the effect of hardening temperature on microstructure, wear and corrosion resistance of Fe-Al-Mn alloy grinding ball. Methods: Hardening process was carried out at 900oC, 950oC, 1000oC, 1050oC and 1100oC, held for 60 minutes and cooled using SAE 20 oil. Tests included chemical composition, SEM-EDS, wear and corrosion resistance test. Results: Chemical composition test results show that this alloy is high alloy steel because it contains 3.6% aluminum (Al), 13.6% manganese (Mn) and 1.1% carbon (C). Microstructures found are austenite, ferrite and kappa. EDS test results show that in the austenite phase, C decreased when hardening temperature increased. Ferrite phase contains Mn which increased when hardening temperature increased while C was the other way around. Mn is relatively stable in the kappa phase. The best wear and corrosion resistance (4.3 x 10-7 mm2/kg and 0.00026 mm/yr) of hardened Fe-Al-Mn grinding ball occurred at 900oC. The corrosion rate is extraordinary. Conclusion: Microstructures of the Fe-Al-Mn alloy grinding ball after the hardening process are austenite, ferrite and kappa.

Revised Lewis Bending Stress Capacity Model

Background: During operation, cylindrical gearset experiences tangential, radial, and axial (helical gears only) force components that induce bending, compressive, and shear stresses at the root area of the gear tooth. Accurate estimation of the effective bending stress at the gear root is a challenge. Lewis was the first person who attempted estimating the root bending stress of spur gears with some reasonable accuracy. Various gear standards and codes in use today are modifications and improvements of the Lewis model. Objective: This research aims at revising the Lewis model by making adjustments for dynamic loads, shear stresses, axial bending stress for helical gears, and stress concentration factor that is independent on the moment arm of tangential or axial force component. Methods: An analytical approach is used in formulating a modified formula for the root bending stress in cylindrical gears starting with the original Lewis model. Intermediate expressions are developed in the process and works from many previous authors are reviewed and summarized. The new model developed is used to estimate the root bending stress in four example gearsets of 0o to 41.41o helix angle and the results are compared with those of AGMA (American Gear Manufacturers Association) formula. Results: Analysis from the examples shows that neglecting the radial compressive stress over-estimated the root bending stress by 5.27% on average. When shear stresses are ignored, the root bending stress is under-estimated by 7.49% on average. It is important, therefore, to account for both compressive and shear stresses in cylindrical gear root bending stress. When the root bending stress estimates from the revised Lewis model were compared with AGMA results, deviations in the range of -4.86% to 26.61% were observed. The stress estimates from the revised Lewis formulae were mostly higher than those of AGMA. Conclusion: The new root bending stress model uses stress concentration factors (normal and shear) that are independent of the point of load application on the gear tooth. This decoupling of stress concentration factor from the load moment arm distinguishes the new model from AGMA formula and brings bending stress analysis in gear design in line with classical bending stress analysis of straight and curved beams. The model can be used for both normal contact ratio and high contact ratio cylindrical gears.

The Efficient and Tentative Model for Extenics Replications of the Moveable Robots

Background: On the most elementary level, you and I (human beings) were created with five main mechanisms (or parts): • A body which is termed as the main structure of the human being. • A sensory system that takes certain information around the body and the immediate environment. • A muscle system to aid the body move easily. • A control base to trigger the muscles and sensors. • A brain system that develops sensory data and tells the muscles what to do in other words the way forward. Obviously, we likewise have some imperceptible qualities, for example, intellect and ethics, among others but on an absolute corporeal level. Robots, on the other hand, can be created with five main mechanisms or more. Objectives: This research aims at implementing robots in some tedious jobs that as supposed to be executed by human beings in various factories and industries. This study also presents the practical and tentative model for Extenics replications of the moveable mechanical device (robot) useful on VIPRO stage. Methods: Momentary antiquity and indication of the pertinent hypothetical ideas are provided. The intelligent boundary for drawn-out switch uses a novel element for synthetic intelligence which is drawn-out control (Extenics) to expand DHFPC switch rapid enactment of mobile robots. Result: Applying Extenics specific methods and application in vague interplanetary result in a novel, advanced application for the VIPRO stage which can be used to feign and device innovative switch approaches of moveable robots.

Controllable Magnetoactive Polymer Conduit

Objective: Magneto-active Polymers (MAP) are smart materials whose mechanical characteristics, such as elastic and shear moduli, may be controllable by means of an externally applied magnetic field. Methods: Various additives may be used to influence the characteristics of the polymer matrix whilst a suspension of soft and/or hard magnetic particles determine the magnetic properties of the composite. Both pre-cure and post-cure magnetization is possible. Results: A range of control strategies have been investigated for evaluation of the system using fluids of differing kinematic viscosity. Conclusion: Depending on the degree of magnetic field homogeneity, magneto-deformation and magnetostriction contribute to MAP actuation. This paper presents a novel application in the form of a peristaltic MAP tube system, applicable to flow control and pumping of hemorheological fluids in blood circulatory systems for biomedical research purposes.

Experimental Studying of the Variations of Surface Roughness and Dimensional Accuracy in Dry Hard Turning Operation

Objective: Hard turning in dry condition using cubic boron nitride tools, as an alternative of traditional grinding operation, is an advanced machining operation in which hardened steel with the hardness greater than 46 HRc is machined without the use of any coolant. Method: In the hard turning process, due to its hard nature, usually the cutting depth is selected lower than or equal to the nose radius, and the cutting zone is mainly limited within the tool nose area. Thus, unlike the traditional turning, the effect of the nose radius on the surface finish and dimensional accuracy becomes more complicated. Therefore, in this paper, firstly, the effect of processing parameters such as nose radius on the surface roughness and dimensional accuracy is investigated. Then, the relationship between the surface finish and dimensional accuracy variations with vibration, cutting forces, and tool wear is studied experimentally. The results revealed that feed rate is the most important factor influencing the surface roughness, whereas spindle speed and cutting depth are insignificant factors. On the other hand, cutting depth and spindle speed have the greatest effect on the dimensional accuracy, while nose radius has no significant effect. The vibration and wear analysis revealed that compared with the vibration, the tool wear has no considerable effect on the dimensional accuracy. It was also observed that the spindle speed has a contradictory effect on the surface roughness and dimensional accuracy. The best dimensional accuracy is obtained at 500 rpm, while the best surface quality is achieved at 2000 rpm. Result: The obtained results also showed that increasing the feed rate from a particular value not only leads to no significant changes in the surface roughness value but in some cases can also decrease the surface roughness. Conclusion: According to the analysis results, the lowest cutting depth, the moderate feed rate, and the speed lower than 1100 rpm provide the best dimensional accuracy. Compared with carbides and ceramics, cubic boron nitride tools produce a better surface roughness at both higher cutting depth and speed. 0.202 µm is the best surface roughness that was obtained at rε = 1.2 mm, N = 2000 rpm, f = 0.08 mm/rev, d = 0.5 mm which is comparable with the surface quality obtained by the conventional grinding operation.

An Alternate View of Dimensional Homogeneity, and Its Impact on Engineering Science

Aims:This article proposes an alternate view of dimensional homogeneity that greatly simplifies the solution of nonlinear engineering problems.Background:The conventional view of dimensional homogeneity is generally credited to Fourier (1822).Objectives:The objectives of this article are to describe the alternate view of dimensional homogeneity and to demonstrate its application to practical engineering problems.Methods:By presenting the solution of several nonlinear engineering problems, this article compares solutions based on the alternate view of dimensional homogeneity with solutions based on the conventional view.Results:Example problems demonstrate that nonlinear engineering problems are much easier to solve if the solutions are based on the alternate view of dimensional homogeneity rather than the conventional view. The relative simplicity results because the alternate view of dimensional homogeneity reduces the number of variables in nonlinear problems.Conclusion:The widely accepted view of dimensional homogeneity should be replaced by the alternate view because the solution of nonlinear engineering problems is greatly simplified.

Realistic Stacking Sequence Optimisation of an Aero-Engine Fan Blade-Like Structure Subjected to Frequency, Deformation and Manufacturing Constraints

Aims:A procedure to optimise the stacking sequence of a composite fan blade-like structure is proposed in this article. The aim of the optimisation is to minimise weight when respecting deformation, frequency and strain constraints. The literature often deals with stacking sequence optimisation of airplane wings or wind turbine blades whilst less attention has been dedicated to aero-engines fan blades, the objective of the present paper. The manufacturing constraints are also implemented in the optimisation process in order to obtain a manufacturable structure.Background:Stacking sequence of composite laminates can be tailored to drive the deformation towards the desired shape (potentially exploiting unbalanced laminates and their anisotropy). When optimising the stacking sequence (including blending/tapering) of an aero-engine fan blade-like structure, manufacturing constraints must be included in order to apply the results of the optimisation procedure into a “Real World” design.Objectives:To define an engineering procedure able to provide a good design point to minimise the weight of a fan blade-like structure subjected to deformation (tip extension and untwist), frequency and strain constraints.Methods:A two-level optimisation procedure is proposed. At the first level, the stacking sequence is optimised in such a way to maximise stiffness (and therefore to minimise deformation). Less stringent limits are applied to the constraints of such a level 1 optimisation. In the second step of the optimisation, the blending/tapering of each ply of the stacking sequence is searched.Results:The fan blade-like structure is loaded only with a centrifugal load (the main load acting on this kind of components). The stacking sequence obtained to minimise the weight contains 42.3% of 0 degrees fibres, 19.25% of 45 degrees fibres, 19.25% of -45 degrees fibres and 19.2% of 90 degrees fibres. Blending in terms of width and length of each layer is given in the numerical results section.Conclusions:When the fan blade-like structure is loaded with a centrifugal force only, in order to minimise weight by respecting untwist, tip extension, frequency and integrity constraints, no unbalance in the laminate has been found necessary. An “Optimum” point has been found after a two steps optimisation. This design point is claimed as a good industrial design point rather than as “optimum” in the mathematical sense. Such a “Best Solution” design point has been verified by exploring the design space near it. All the performance of the neighbour points has been found worse. A comparison between a quasi-isotropic laminate and a zero degreed dominated laminate has been also performed.

Lay-up Optimization of Laminated Composites Using a Modified Branch and Bound Method

Background:Composite materials are widely used in the aerospace, marine and automotive industries. One of their main advantages is that their stacking sequence can be tailored to maximise/minimise a specific structural performance. Efficient and non-computational-expensive algorithms are always needed to find the optimum stacking sequence of a composite laminate whose thickness is either to be minimised or may be kept constant (i.e.the thickness and the plies orientation percentages are pre-determined; the problem of the optimisation is therefore permutational).Objective:A modified branch and bound algorithm is proposed here and used to determine the stacking sequence for single and multi-objective optimisation problems. Laminate thickness and orientation percentages are either variables or determined a priori (the optimisation problem is therefore permutational). Computational time is drastically reduced when compared with other meta-heuristic techniques.Methods:The proposed method is a branch and bound algorithm, modified from the original work proposed by Kim and Hwang [10]. The main novelty is the starting point of the optimisation sequence: a laminate formed by “Ideal” layers, described in this paper.Results:The modified branch and bound has been first tested with a laminate having fixed thickness and a fixed percentage of layer orientation. Three different problems have been investigated: maximisation of natural frequencies, minimisation of tip deflection and maximisation of buckling critical load. The algorithm has been also tested, secondly, for a problem of weight minimisation subjected to buckling and strength constraints.Conclusion:The MBB has been shown to give good fidelity and significant computational advantages compared with a GA. Despite the simplicity of the structures in the numerical examples, it is anticipated that the MBB can be used to determine lay-ups in multi-part structures. The method was used to determine stacking sequences for several problems. The modified branch and bound method was shown to determine good laminate designs and offer significant efficiency savings.A “Good Design” is here defined as a solution producing “Near Global Optima” fitness values by minimising the computational effort. It was shown that for a single objective without ply competition, global optima were obtained.

Micro Hybridized Auto-rickshaw for Bangladesh: A Solution to Green Energy Vehicle

Background:Auto rickshaws are compact, three-wheeled vehicles which are normally used altogether in numerous Asian nations (i.e.China, Japan, Bangladesh, India, Pakistan and so forth) for transportation of people and products. The vehicles are little and have simple transportability in occupied Asian cities. In Bangladesh, auto rickshaws/simple bicycles regularly offer their taxi services, as they are fantastically reasonable to work. Simultaneously, these three-wheelers running on fuel cause extreme air-pollution and create impressive measures of greenhouse gasses (i.e.Carbon dioxide).Objectives:This paper introduces a transportation system in view of auto rickshaws that work in an eco-accommodating way. Existing vehicles are to be substituted by a small scale-cross sort framework overhauled in a way which helps the productivity of the vehicle.Methods:A reviving foundation is suggested that will take into consideration the power-packs to be charged utilizing halfway energy, for example, solar energy. Necessary simulations had been done using MATLAB platform.Results:Results shows that the current vehicle and nature, in which it works, made a model of the vehicle and researched re-charging infrastructure prerequisites and plans. About 31% efficiency was observed.Conclusions:The objective of the research introduced in this paper is to build up a conservative, vigorous and feasible fuel utilization system and deplete auto-rickshaws. In this research, 23% of grid power savings has been found.

Design and Experiment of a Replant Crops Separating Garlic Harvester

Background: Garlic is one of the main economic crops in China and the planting area is increasing quickly. But the harvest process of the garlic mainly relies on manual digging, resulting in low harvest efficiency and high cost. Objective: In order to improve the efficiency of garlic harvest, and achieve the mechanization of garlic harvest. The study presents a new design of a garlic harvesting machine that can perform automatic processing and deal with the issue of garlic harvesting. Methods: Firstly, the three-dimensional model of the whole machine and the key mechanism is established and the parameters of the system are calculated by theoretical calculation. Then, the simulation be made and the design be optimized. Finally, the design was processed into a product. It employs an isolation mechanism and positioned cutting mechanism to isolate garlic and crop stubbles and keep the length of the remaining garlic straw consistent. Results: The results of field harvest experiments show that the miss digging rate, miss cutting rate and injury rate of the harvester are as low as 1.23%, 3.13% and 0.68% respectively, and the harvest efficiency is 0.06km2/h. Conclusion: The advantages of the harvester such as high harvesting rate, low damage rate, strong adaptability and high versatility, effectively improve the working efficiency, reduce the labor intensity and the harvest cost.