Design Of Mechanical Components Research Articles

MECHANICAL ENGINEERING OF ROBOTIC SYSTEMS BY SOLIDWORKS

"The modern design studies involve many aspects of product development starting from the concept-zero, continuing with the evaluation and optimization of the structure designed according to many criteria (kinematics, dynamics, strength of materials of mechatronic systems) and ending with specifications for prototype execution. This article evidences design methodologies used in engineering practice in all the design phases, assisted by the professional CAD program, Solidworks. CAD performances of professional software, by modelling and simulation, contribute to a better evaluation of the research results and to the integration of design into manufacturing phases. These aim to reduce the time from product concept up to it is launched in the market. In the case of robots and complex mechatronic systems, special attention is focused on the mechanical components concept and design so that they enable required motions – trajectory, speed, acceleration. Results of kinematic analysis for two new robotic systems obtained by modelling and simulation using SolidWorks software are presented. There were considered specific phases that are: fully study of requirements; set constraints; concept; 3D CAD model; kinematic analysis; simulation; interpretation of results and conclusion. Finally, relevant benefits of the research for the real case studied are enhanced. By using professional software for evaluations, it is efficient to make video presentations at an outstanding level which summarizes the evaluation of the studied phenomena and enlightens the research results. "

An efficient mechanical metamaterial component with alternating Poisson's ratios and opposite orthogonal behaviors

In some extreme environments, mechanical metamaterials can be actuated by mechanical actuating instead of electronic controls to realize functions such as mechanical signal output, logic gate operations, or other self-decision functions. This paper proposes a three-dimensional mechanical metamaterial with alternating Poisson's ratios and opposite orthogonal behaviors (AOPR metamaterials). The alternating Poisson's ratios enable AOPRs to complete the alternating action under only one-time unidirectional actuating action. The orthogonal opposite behaviors enable AOPRs to simultaneously perform signal output in two directions and binary logic control. These two unique properties greatly enrich mechanical metamaterials’ information expression ability and logical judgment ability. Using AOPRs as mechanical components can significantly reduce the temporal and spatial consumption required to complete logic operations or control functions. We expect to provide a mechanical component design strategy for helping mechanical computers and automatic controllers reduce the structural volume and improve the operational speed.

Design of mechanical components for Brushless DC Motor

هدف از این تحقیق طراحی اجزای مکانیکی جهت ساخت یک موتور مغناطیس دائم بدون جاروبک می-باشد. در طراحی این موتور، از روتور و شافت ‌یک‌پارچه استفاده شده و جهت امکان دسترسی به فضای داخل و کاهش وزن، روتور به‌صورت توخالی درنظر گرفته شده است. با توجه به میزان چگالی شار مغناطیسی و در‌نظر گرفتن استحکام مورد نیاز در روتور جهت تحمل کردن بارهای وارد بر آن، فولاد 52St- و برای اتصال بین آهن‌رباها و روتور از چسب با استحکام بالا، ساخته شده از روتیوب اپوکسی استفاده شده است. به منظور بررسی استحکام موتور، اجزای موتور شامل قطعات انتقال دهنده قدرت و اجزای نصب موتور مورد آنالیز قرار گرفتند. اثر نیروی گریز از مرکز در تنش نرمال ایجادشده بر روی روتور، اثر گشتاور انتقالی از روتور در ایجاد تنش پیچشی بر روی شافت، میزان تنش برشی در محل اتصال قطعات آهن‌ربا به روتور و میزان تنش وارد بر قطعات پایه و نیروی لازمه پیچ‌ها برای مهار نیروی وارده بر اثر وزن موتور بر پایه‌های نگه‌دارنده موتور، توسط نرم‌افزار نسترن تحلیل گردید. با توجه به تحلیل تنش روتور و شافت، با انتخاب فولاد St-52 برای این قطعات، ضریب اطمینان 58/2، به‌دست آمده است. تحلیل تنش برشی محل اتصال آهن‌رباها با روتور نشان‌دهنده اتصال مناسب این قطعات توسط چسب مورد استفاده در این تحقیق با ضریب اطمینان قابل قبول 61/1می‌باشد.

The influence of Λ ratio and surface roughness on the initiation and progression of micropitting damage

Micropitting is a major failure mode in gears and rolling bearings. Despite its practical importance, there currently exist no universally accepted design guidelines for its prevention primarily due to the great number of influencing parameters. In the absence of an established criterion, the Λ-ratio (the ratio of lubricant film thickness to surface roughness) is often used as a simple way to assess the risk of micropitting. In this paper we present new data to establish and decouple the individual effects of two of the most important influencing parameters in micropitting: the surface roughness amplitude and Λ-ratio. The experiments are conducted on a triple disc contact fatigue rig and carefully designed to decouple the effect of roughness from that of the Λ-ratio. To isolate the influence of the Λ ratio, we use specimens with the same and very tightly controlled surface roughness and then vary the film thickness by blending different viscosities of the same PAO base oil while keeping all other influential parameters constant. To isolate the influence of surface roughness, we keep the Λ ratio the same using the same PAO oils with appropriate viscosities while changing the RMS roughness of the specimen and keeping other roughness parameters as constant as possible. All tests use case carburised 16MnCr5 gear steel specimens. Results show that higher Λ ratio at fixed roughness produces less micropitting as may intuitively be expected. More importantly, at a fixed Λ ratio the amount of micropitting damage was extremely sensitive to the actual surface roughness, with lower roughness both lengthening the micropitting incubation phase and decreasing the rate of material loss in the micropitting wear phase. This shows that Λ ratio on its own cannot be used to assess the risk of micropitting because it is not able to account for the effects of different roughness levels on micropitting, despite including roughness in its definition. Furthermore, in relative terms micropitting was more sensitive to surface roughness than to Λ. In addition, we show that there exists a sufficiently low surface roughness below which micropitting is unlikely to occur even at extremely low Λ ratios. The results presented here can help in design of gears and other mechanical components to mitigate against micropitting.

Failure Analysis of the Screw Press Machine

In this paper, an analysis of the mechanical components of the Screw Press Machine is carried out in the form of an analysis of the design of mechanical components, maintenance cycles and remaining life. From the design analysis of mechanical components, it is known that the stresses that occur in the screw are in the form of nominal shear stresses of 18.18 N/mm², axial stresses of -10.41 N/mm², bending stresses of 54.66 N/mm², and shear stresses acting on the base screw of 65.41 N/mm². The number of press cycles that occur in one hour is 121 cycles. Number in the press cycle that occurs in the worm screw press is 2.625x105 cycles. In field conditions with pressure fluctuating between 30-40 bars, the life time of using a worm screw press is around 2169.43 hours.

Bir Yarı-düzlemde Yüzeyaltı Termoelastik Temas Gerilmelerinin Sıcaklık Bağımlı Özellikler Kullanılarak Belirlenmesi

Contact mechanics problem between a rigid punch and a homogenous half-plane is examined considering frictional heat generation. Friction between the sliding rigid punch and the surface of the half-plane leads to a frictional heat which directly flows towards the half-plane material without a loss, and it changes the material’s thermoelastic properties. Calculation of subsurface stresses is crucial in the aspect of mechanical design of components since most of failures arise from fatigue and fracture at regions where subsurface stresses reach higher levels. In order to solve the problem, an iterative algorithm is developed based on the finite element method. Steady state subsurface contact stresses are obtained once the frictional heat on the contact surface reaches equilibrium. Subsurface stresses are calculated for different values of punch sliding velocity and coefficient of friction. It is observed that difference between subsurface contact stresses calculated based on temperature dependent and temperature independent properties is remarkable. Higher values of punch velocity and coefficient of friction leads to greater amount of heat generation, and percent difference between stresses reaches significant level especially near the contact surface. The utilization of temperature dependent material properties provides better approximation in assessing fatigue and fracture behavior of machine parts subjected to frictional contact with heat generation.

Processing of Data Obtained by the Testing of Steel under Low Cyclic Fatigue (Part I)

The design of mechanical components exposed to fatigue load, at a low number of cycles, requires knowledge of the behaviour of the material under the impact of variable load in conditions of controlled strain when cyclic plasticity is present. The aim of testing the quality of the material of the components exposed to low cycle fatigue (LCF) in many industries: nuclear, aerospace, mechanical, civil engineering and shipbuilding. In order to ensure the reliability and consistency of the results from different laboratories, it is necessary to collect all test data using test and data processing methodologies that are in accordance with a number of key points of ISO 12106:2017 and/or ASTM E 606-04 standards. This paper defines a new data processing methodology after the LCF testing of steel.

Performance Comparison of Recent Population-Based Metaheuristic Optimisation Algorithms in Mechanical Design Problems of Machinery Components

The optimisation of complex engineering design problems is highly challenging due to the consideration of various design variables. To obtain acceptable near-optimal solutions within reasonable computation time, metaheuristics can be employed for such problems. However, a plethora of novel metaheuristic algorithms are developed and constantly improved and hence it is important to evaluate the applicability of the novel optimisation strategies and compare their performance using real-world engineering design problems. Therefore, in this paper, eight recent population-based metaheuristic optimisation algorithms—African Vultures Optimisation Algorithm (AVOA), Crystal Structure Algorithm (CryStAl), Human-Behaviour Based Optimisation (HBBO), Gradient-Based Optimiser (GBO), Gorilla Troops Optimiser (GTO), Runge–Kutta optimiser (RUN), Social Network Search (SNS) and Sparrow Search Algorithm (SSA)—are applied to five different mechanical component design problems and their performance on such problems are compared. The results show that the SNS algorithm is consistent, robust and provides better quality solutions at a relatively fast computation time for the considered design problems. GTO and GBO also show comparable performance across the considered problems and AVOA is the most efficient in terms of computation time.

Numerical investigation of the mechanical component design of a hexacopter drone for real-time fine dust monitoring

Numerical investigation of the mechanical component design of a hexacopter drone for real-time fine dust monitoring

Shear and vortex instabilities at deep part load of hydraulic turbines and their numerical prediction

For all types of turbines, deep part load operation (DPL) poses a challenge. An example of a dynamic phenomenon due to vaneless space vortices occurring at DPL is presented for three turbine types: a diagonal, a propeller and a Francis turbine. The backflow region occurring at DPL is often considered to be a main factor in these phenomena. Our results confirm that these backflow regions play an important role, but other factors also seem to be significant in specific cases. In our example of a diagonal turbine, the intersection of the backflow region with the leading edge of the blades seems to generate particularly high pressure pulsations and vibrations. In the case of the propeller turbine, large vaneless space vortices are found in CFD, but vibrations on the prototype machine are well within acceptable levels. Inspecting the flow at an operating point before large vaneless space vortices occur, shows high shear levels near the inner head cover that generate the high-intensity vortices at an even lower load. In the Francis turbine, half the number of strong vaneless space vortices interact with equally strong inter-blade vortices with vorticity of opposite sign to result in high dynamic blade torque. CFD simulations are well capable of capturing these phenomena, allowing them to be considered in the mechanical design of the turbine components for safe operation.

Advanced Metaheuristic Techniques for Mechanical Design Problems: Review

The design of complex mechanical components is a time-consuming process which involves many design variables with multiple interacted objectives and constraints. Traditionally, the design process of mechanical components is performed manually depending on the intuition and experience of the designer. In recent decades, automatic methods have been proposed to effectively search diverse and large parameter spaces. There is a growing interest in design optimization of mechanical systems using metaheuristic algorithms to improve the product lifecycle and performance and minimize the cost. Nowadays, there is a growing interest in design optimization of mechanical systems using metaheuristic algorithms to improve the product lifecycle and performance and minimize the cost. This review article demonstrates the applications of different metaheuristic algorithms in enhancing the design process of different mechanical systems. First, the basic concepts of common used metaheuristic algorithms are introduced. Then the applications of theses algorithms in optimization of different mechanical systems are discussed.

Real Results from Sailing Simulation [America's cup yacht racing

This article discusses the research and development methods used by the British Ineos Team UK whilst competing for the America's cup in yacht racing 2021. This year's rules minimised the time and methods allowed for physical testing, resulting in essential hours of parallel run sailing simulations utilising CAD files, along with computational fluid dynamic modelling run on Simcenter's STAR-CCM+ software. Structural and mechanical feature design of boat components including foils, hulls, masts, rudders and sails were also explored along with weather conditions such as wind, and forces such as drag, lift, yaw, pitch, flow and roll, with feedback gathered from 100 different points on the simulated boat. Virtual-reality headsets and graphics are used alongside a motion platform for sailors to train on the simulated models.

Design for Manufacturing: Geometric Manufacturability Evaluation for Five-Axis Milling

Abstract The geometric manufacturability of a part design is an important decision factor for various manufacturing applications and is especially critical for the machining process. In machining, the geometric manufacturability is primarily determined by geometric accessibility, which has a direct impact on decisions such as setup planning, tool selection, tool orientation selection/adjustment, and the tool path strategies. These planning decisions can have a significant impact on cycle time and cost. Thus, it can be justified that geometric manufacturability is one of the essential product design aspects that must be evaluated for machining processes. Being able to evaluate the geometric manufacturability will not only provide a part design metric but also offer a new approach for manufacturing process planning and optimization. This research proposes a new method for determining the geometric manufacturability of a part designed for five-axis milling. In this work, the part design is input as polygon mesh boundary represented models, the 3D tool geometry is sampled to line segments, the 3D geometric accessibility of the part design is calculated, and a new metric for five-axis milling manufacturability evaluation is developed. Case studies on complex mechanical component design examples are conducted to validate the method.

Constructionist Learning Tool for Acquiring Skills in Understanding Standardised Engineering Drawings of Mechanical Assemblies in Mobile Devices

The purpose of Graphic Design is to transfer information about design into reality and concerns the analysis, design and representation of mechanical components and assemblies. For the correct rendering of mechanical components, this discipline requires a command of, and the ability to, manage techniques and systems for graphical representation and standardisation; 3D models in a virtual environment enable engineering students to develop graphical skills and spatial awareness. The objective of the present study is the development of an application for smart devices (mobile phones and tablets), based on the constructionist theory of learning, which will enable first year engineering degree students to acquire the technical drawing knowledge and skills necessary to render mechanical assemblies. The mobile application tested and designed in this work is called ARPAID. It is a learning tool aimed at teaching students about the representation of mechanical assemblies as part of an engineering Graphic Design course. Teaching material and a process for evaluation have been designed. A detailed description is given of a classroom activity accompanied by a tabulation and analysis of the results obtained. This mobile application, when used in a Graphic Design course, promotes a more rapid understanding of spatial relationships and problems, fosters students’ learning and motivation, and develops higher order skills. Results from before and after the use of the application will be presented and do indeed show significant improvements in student performance.

Research and Design of Household Intelligent Mechanical Claw

In order to design a kind of intelligent mechanical claw for home and office scene. Based on the investigation, analysis and arrangement of the features of items in the family and the functional demands of the family on the mechanical claw, a design scheme of intelligent mechanical claw which can switch functions and grasping modes according to the different grasping objects is proposed. Mechanical structure design, including mechanism motion design, part structure design, and use Autodesk Inventor software for mechanical parts, component design and simulation assembly; The stress analysis module in Autodesk Inventor was used to simulate the key components. Finally, the design scheme of mechanical structure and control system for the mechanical claw are proposed.

Free vibration characteristics of flax fiber/ expanded polystyrene waste composite

Nowadays, the concern of damping and vibration has become an important parameter in the design of structural and mechanical components for which the cyclic loading and vibration reductions are critical. Due to this reason, recently natural fiber thermoplastic composites are suitable for many anti-vibration application areas due to their high specific strength and viscoelastic behavior together with high damping properties compared to conventional materials. A few works were studied the free vibration characterization of composite materials. However, the free vibration studies of the current composite material have not been sighted in the literature yet. Thus, this paper focused on the fundamental frequencies and damping ratios of flax fiber expanded polystyrene waste (FFEPS) composites of 20%, 30% and 40% fiber content. The FFEPS composites were prepared using compression techniques and tested using ASTM E756 standards. The experimental evaluation are determined by using the accelerometer sensor and sets to Data Acquisition System (DAS) which is connected to the PC and assimilated with Lab VIEW software. Additionally, the natural frequencies were also evaluated by using analytical and numerical (using ABAQUS). The composite damping ratio was determined by using the logarithmic decrement method. The result displayed that the damping ratio of the composites has decreased with an increase in fiber loading. The values of natural frequency by analytical and numerical methods are in close agreement with experimental results.

Integration of Low Melting Temperature Electrolyte in Thermal Batteries

Thermal batteries usually operate at temperatures higher than 400 °C. This high operating temperature requires a complex thermal and mechanical design of the battery components and hermetically sealed casing. Reduced operating temperature thermal cells can benefit from the majority of intrinsic characterizations of thermal batteries such as safety, robustness, and infinite shelf life while mitigating the challenges related to the high operating temperature batteries such as exotic thermal insulation materials, complicated internal pyrotechnic heat source, and heavy packaging. To integrate the thermal batteries into a wider range of applications such as bore-hole probes, smart grid energy storage, and geothermal energy applications, operating temperatures of these batteries should be reduced.The most common design for thermal batteries is pellet stacks. The pellet pressing fabrication method inherently causes issues due to the fragility of the pellets, making handling and assembly of the cells arduous. Additionally, due to the liquid nature of molten salt electrolyte used in these batteries, a structure to immobilize the electrolyte layer during the operation of the battery is required. The role of the immobilizing component is also to prevent short circuiting while the battery is affected by severe physical shock or vibration. The most commonly used binder material in today’s thermal batteries is magnesium oxide (MgO). Extensive investigations were conducted on the properties and the electrochemical effect of using MgO as the binding material, besides, its fabrication process is well optimized. However, using MgO is not without its drawbacks. To prevent short-circuiting during the cell operation especially in the presence of an external shock to the system, approximately 30 vol.% of the separator layer should be dedicated to MgO, resulting in lower than desired energy density. Ceramic felts showed promising results in recent studies. High level of porosity (e.g. 96% bulk porosity), outstanding stability at elevated temperatures, and mechanical stiffness could be the key to make batteries that can operate for a longer time.Our research group has previously developed a novel eutectic electrolyte mixture using potassium bifluoride and different lithium salts such as lithium fluoride as the low melting point electrolytes. In this research, initially, the integration of this electrolyte mixture in a thermal cell was tested. Consequently, aluminum oxide (Al2O3) and yttria-stabilized zirconia (YSZ) ceramic felts were loaded with the low melting electrolyte as an alternative to the current pellet-based separator layer. Finally, (i) the assembly of the cell, (ii) the thermal analysis of the components by differential scan calorimetry (DSC) method, (iii) the new electrolyte/ceramic-felt combination’s loading level, wetting properties, infiltration, and leakage, and (iv) electrochemical behavior of the new thermal battery such as discharge capability and energy density were investigated.

The mine blast algorithm for the structural optimization of electrical vehicle components

Abstract The shape optimization of mechanical and automotive component plays a crucial role in the development of automotive technology. Presently, the use of derivative-free metaheuristics in combination with finite element analysis for mechanical component design is one of the most focused on topics due to its simplicity and effectiveness. In this research paper, the mine blast algorithm (MBA) is used to solve the problem of shape optimization for a vehicle door hinge to prove how the MBA can be used for solving shape optimization problems in designing electrical vehicles. The results show the advantage of the MBA for designing optimal components in the automotive industry.

Derivation and analysis of a combined fretting wear-fatigue model based on the asymptotic equivalence between perfect plasticity and friction

Fretting analysis may be of critical importance in the design of mechanical structural components when the contact interfaces are subjected to cyclic tangential loading. Indeed, fretting damage may induce various mechanisms of failure, such as wear, but may also lead to fretting fatigue through the early development of embryo cracks than can result in a significant decrease in fatigue performance. In the present paper, an original theoretical model encompassing both phenomena is proposed, as derived from the proven asymptotic equivalence between perfect plasticity and friction and using a continuum damage approach in the intermediate perfectly plastic volume of small thickness. This asymptotic process enables to obtain a law for sliding wear rate evolution and a fretting-fatigue law in the low-cycle fatigue regime based on a unified approach. Both parts of the resulting model are discussed and analyzed in detail by comparison or analogy with existing approaches from the literature on the topic. A detailed strategy for numerical implementation is finally addressed at the end of the paper.

Designing stress for optimizing and toughening truss-like structures

Optimization of materials and structures is a crucial step in the design of man-made mechanical components for a wide field of engineering applications. It also plays a key role in mechanobiology of living systems, being involved by nature across the scales, from single-cell to tissues and organs, as a strategy to minimize metabolic cost and maximize biomechanical performances. The synergy between the continuously increasing development of high-resolution 3D printing technologies and the possibility to predict chemical and physical properties through molecular dynamics-based numerical analyses has recently contributed to boost the use of both design and topology optimization procedures. They are employed in ab initio simulations as key strategies for deciding microstructures to improve mechanical performances and, concretely, to achieve prototypes of new material components. With this in mind, we here propose to abandon the classical approach of using a single scalar objective function employed in the classical design and topology optimization strategies, to introduce multiple quantities to be minimized, identified as the differences between material yield stress and the maximum von Mises stress. After mathematically justifying the well-posedness of this unconventional choice for the case at hand, it is highlighted that the proposed strategy is based on the concept of "equalizing" a proper stress measure at any point of the body and, for this reason, it is baptized as Galilei’s optimization, in honor of the Italian scholar who somehow first wondered about the possibility of changing sizes of beams to have uniform internal forces and, in turn, minimum weight. By exploiting analytical solutions and ad hoc implementing a parametric finite element algorithm to be applied to a wide variety of solids with arbitrary complex structural geometries, including nested or hierarchically organized architectures, it is first demonstrated that the proposed optimization strategy roughly retraces principles invoked by nature to guide growth, remodeling and shaping of biomaterials. More importantly, by means of several benchmark examples, we finally show the proposed procedure might be also helpfully employed to conceive a new class of micro-structured, eventually 3D-printed materials exhibiting surprising post-elastic properties, such as high overall resilience and toughness, in particular obtaining a decrease of stress concentration and a slowing down of crack propagation as direct effects of the optimization, which de facto minimizes stress gradients wherever in the solid domain.