Prototype Manufacturing Research Articles

Research and Simulation on Principle of Walking Driving Mechanism for In-Pipe Worming Robot

Aiming at the problem of large drag force of robot in narrow pipe space, a new type walking driving mechanism of in-pipe worming robot was proposed in this paper. The main force-exerting driving is an incomplete gear-rack mechanism, it has the characteristics of high transmission efficiency and good manufacturability. The walking principle and walking step-speed and drag force had been analyzed. When virtual prototype established the simulation experiments analysis were completed, the numerical results are in good agreement with the theoretical analysis, to a certain extent, the rationality and feasibility of the new type walking driving mechanism proposed of in-pipe worming robot had been verified, these provide the basis foundation for the manufacture of physical prototype.

Study on Structural Design and Manufacturing of Sandwich Composite Floor for Automotive Structure

In this work, structural design and manufacturing of sandwich composite floor for automobile was performed. The tensile and compression strength of specimen were investigated. Based on this, structural design of floor board was performed. The sandwich composite floor board are subject to payload. The maximum load was analyzed in consideration of the safety factor. The structural design and analysis were performed in consideration of applied load. The finite element analysis method was applied to investigate structural safety. The stress, displacement, and buckling analysis was carried out. Through the structural analysis, it was confirmed that the designed floor board structure is safety. Based on the result, the manufacturing of prototype was conducted. Finally, test and evaluation of composite floor board was performed.

Optimization Of Process Parameters In 3d Printing-Fused Deposition Modeling Using Taguchi Method

3D printing or Rapid Prototyping (RP) or Additive Manufacturing (AM) is an innovative manufacturingmethod that is mostly used for prototypes in various Industries such as Aerospace, Defense, Medical, Automotive, etc. One of the worthy and widely used 3 D printing techniques is Fused Deposition Modeling (FDM), which involves adding melted material layer by layer. FDM has several benefits over other manufacturing methods. While setting the 3 D printing options, we have to take several parameters into account, such as speed, layer thickness and infill density, etc. The present experimental work illustrates the performance of ABS built parts fabricated by AION 500 make FDM machine. The quality of parts produced by FDM process mainly depends on the selection of process parameters. The present research work consists of process parameters such as layer thickness, infill density and speed of deposition, etc. This study aims to find effects of process parameters on different performance parameters i.e., mechanical considerations (impact strength), build time, surface roughness in a systematic manner with less number of experimental runs. Taguchi design of experiment (DOE) approach has been used to save cost and time of experimentation. Statistical significance of process parameters is analyzed using analysis of variance (ANOVA). The significant parameters for optimum results and optimal parameter setting has been suggested using S/N ratio.

Оценка ресурса и характеристик изоляции тяговых двигателей локомотивов методом ускоренного теплового старения

Objective: An equivalent mode of accelerated thermal aging of the insulation system of electrical ma- chines is described to confirm the resource corresponding to a given period and operating conditions. Methods: The equivalent mode of accelerated heat aging was determined based on the Montzinger rule and tested in the course of research and development work (R&D) on the development, manufacture and implementation of a set of bench and operational tests of the insulation system of an increased heat resistance class of a diesel locomotive traction motor. Results: The relevance of R&D has been revealed, as a result of which the implementation of the idea was required, based on the statement about the re- duction of the insulation resource of electrical machines when the permissible heating is exceeded by 8–12 °С to various types of insulating materials. The advantages of the method presented in the article in relation to traditional solutions of this problem are demonstrated, and also improved consumer proper- ties of the traction electric motor of a diesel locomotive with a replaced insulation system of an increased class of heat resistance are presented. Generally, experimental tests and preliminary operational data are an acceptable basis for thermal evaluation of electrical insulating materials. However, it is important to remember that the scientific criterion is met and not to use the results of different types of tests in the analysis. Based on the world experience in diagnostics of additional insulation parameters for monitoring the state of insulation parameters, the possibility of using the “Doctor” series insulation monitoring de- vices has been determined and practically confirmed. Together with the results of subsequent operational tests, during which the insulation was also monitored using these mobile devices, it is argued that after carrying out the relevant research work, thanks to the mobile devices of the “Doctor” series, it is pos- sible to carry out predictive analytics of the failure of traction motors (TED) in any operating conditions. The functional value is determined and applied in practice. The “H” class insulation system developed by the specialists of JSC “VNIKTI” is mainly based on insulating materials produced by JSC “Holding Company „Elinar“”; the compound “Elplast 180ID” (JSC “Electroizolit”) or its analogue “Elkom-180” JSC “Holding company „Elinar“”), for anchor coils and equalizers, a wound PPIPK-2 wire in polyimide- fluoroplastic insulation (GC “Moskabelmet”) is used. Practical importance: It is stated that all stages of manufacturing and testing, determined at the initial stage of R&D, confirmed the results of the deve- lopment stages (overhaul (manufacture) of prototypes of TED using a new isolation system according to the design documentation of JSC “VNIKTI”). Bench tests have confirmed typical characteristics, speci- fied resource and insulation characteristics with equivalent accelerated thermal aging corresponding to an electric motor’s service life of 20 years in ordinary operation on a diesel locomotive, residual life of elements of the insulation system of naturally cut armature segments, main and auxiliary poles coils. In the specialized laboratory of JSC “Holding Company „Elinar“”, an experimental TED diesel locomotive set with the investigated insulation system was manufactured and installed on two sections of the main- line diesel locomotive 2TE116. Operational tests of an experimental TED diesel locomotive set under operating conditions were successful.

DEVELOPMENT AND RESEARCH OF THE AUTOMATED LABORATORY STAND BASED ON THE PROTOTYPE OF THE INDUSTRIAL ROBOT «SCARA»

Experimental development and manufacture of a SCARA-robot prototype for further use in laboratory stands is underway. The description of the experimental prototype, the control principle and the analysis of the results are given.

Rotating Bending Fatigue Analysis of Printed Specimens from Assorted Polymer Materials.

Fused filament fabrication (FFF), as a form of additive manufacturing (AM), in recent years, has become a popular method to manufacture prototypes, as well as functional parts. FFF is an extrusion process, commonly known as 3D printing, where the object is built by depositing melted material layer by layer. The most common materials, i.e., the materials that are most widely used, are polylactic acid (PLA), acrylonitrile butadiene styrene (ABS) and acrylonitrile styrene acrylate (ASA). Although there are lot of research papers that cover the subject of the determination of mechanical properties and characteristics, theoretically and experimentally, as well as the fatigue characteristics of aforementioned materials, there is a lack of research and scientific papers dealing with the problematics of S–N curves based on the rotating bending fatigue analysis of those materials. Consequently, this paper covers the topic of rotating bending fatigue data for 3D printed specimens of given materials, under different loading values.

Vehicular Electrical Distribution System Simulation Employing a Current-Injection Algorithm

Modeling and simulation have been permeating all development areas within the automotive industry, such as structural simulation, powertrain, engine, thermal management, electronics, and also the electrical distribution system (EDS) design. Rapid adoption of simulation techniques has the potential of reducing prototype manufacturing and, thus, vehicle time-to-market. This article provides a methodology toward vehicle EDS simulation based on the current-injection algorithm to calculate electrical variables within the network and detect early phase design problems. This algorithm allows for a high convergence speed of the computed results and is applicable to combustion vehicles, hybrids, or full electrical vehicles (EVs). We compare the simulated results with the measurements on a test bench of a real automotive wire harness and a vehicle prototype to validate the calculated results.

Innovative Fermented Beverages Made with Red Rice, Barley, and Buckwheat.

The increase in food intolerances, allergies, and food-based lifestyle choices has dramatically increased the consumer demand for healthy foods characterized by pleasant sensory traits. In such a context, innovative cereal-based beverages are characterized by high nutritional value, pleasant palatability, and potential healthy properties. In the present study, a pool of 23 lactic acid bacteria strains was preliminary assayed as monocultures for the fermentation of three ad hoc formulated cereal- (red rice and barley) and pseudocereal (buckwheat) -based substrates. Eight strains with the best performance in terms of acidification rate were selected for the formulation of three multiple strain cultures to be further exploited for the manufacture of laboratory-scale prototypes of fermented beverages. The compositional and microbiological features of the three experimental beverages highlighted their high biological value for further exploitation.

Fused filament fabrication of polyetheretherketone/multiwalled carbon nanotube nanocomposites: the effect of thermally conductive nanometric filler on the printability and related properties

AbstractFused filament fabrication is an additive layer manufacturing technique. It was extensively used at the beginning for the manufacturing of prototypes, and it has been adopted during the last few years for the manufacturing of fully functional components. Polyetheretherketone (PEEK) has been thoroughly investigated as a composite matrix because of its outstanding mechanical properties and thermal and chemical stability. This study is focused on PEEK nanocomposites with different amounts of carbon nanotubes (CNTs) (i.e. 3, 5, 10 wt%) produced in the form of a filament and successively 3D printed. The influence of the CNT presence on printability was studied and correlated to the nanocomposite feedstock thermal and microstructural properties, defining a substrate temperature processability window. Interestingly the addition of CNTs significantly limits the processability window due to the influence on the crystallization process and viscosity. Moreover, the thermal and mechanical properties of 3D printed bulk samples were investigated in view of the PEEK/CNT nanocomposite feedstock properties. © 2021 Society of Chemical Industry

Numerical Simulation of Insulin Depot Formation in Subcutaneous Tissue Modeled as a Homogeneous Anisotropic Porous Media.

In this study, a numerical model of insulin depot formation in the subcutaneous adipose tissue of humans has been developed using the commercial computational fluid dynamics software. A better understanding of the underlying mechanisms can be helpful in the development of novel insulin administration devices and cannula geometries. Developing a model of insulin depot formation can provide faster results compared to extensive experimental studies which are typically done on porcine tissues. The injection method considered in this simulation involves an insulin pump that uses a rapid acting U100 insulin analogue. The depot formation has been studied by simulating Bolus injections ranging from 5 to 15 units of insulin, which corresponds to volumes of 50-150 μL. The insulin is injected into modeled subcutaneous tissues typically present in human abdominal regions. The subcutaneous tissue has been modeled as a fluid-saturated porous media. An anisotropic approach has been used to define the tissue permeability. The value of the porosity in parallel and perpendicular directions has been varied to modify the viscous resistance to the flow in these directions. The developed model has been validated by comparing with published experimental results, which show qualitative similarities in disk-shaped insulin depot formation. The validated model is then used to study formation of insulin depot inside the subcutaneous tissue at varying insulin flow rates involving different cannula geometries and arrays. The numerical model has been found to be an effective option to evaluate new cannula designs prior to the manufacturing and testing of prototypes, which can be rather time consuming and expensive.

Voxel Modeling of the Control of Prototype Manufacturing with Additive Technologies

The paper discusses the principles of controlling the parameters of a functional voxel model during the manufacturing of a part prototype using additive technologies. A way to build a functional voxel model based on the mapping of local geometry features is considered. An approach is offered to supporting structures modeling, which employs gradient motion in the space of functional voxel models based on the solidification principle.

Exploring product complexity and prototype lead-times to predict new product development cycle-times

In a world where new product development (NPD) can differentiate winners from losers, reducing NPD cycle-times is a competitive agenda. For complex NPD projects, traditional planning techniques proved to be insufficient for dealing with uncertainty in the current business environment, often failing to provide realistic planning. This study contributes to both the literature and practice by proposing regression models to explore the potential of product complexity and prototyping lead-times for time prediction in NPD projects. Firstly, we identified an NPD reference that could help understand the NPD projects behavior for complex mechatronic products. Secondly, we developed validation procedures to calculate and test our variables. Specifically, several procedures were necessary to reach a value that represented a trade-off analysis of design issues to product complexity. Thirdly, we identified a company for sourcing data for a first falsifiability test to our models. The models presented results up to a 4% error rate, suggesting, compared to previous literature, that the variables explored in this research and how they were handled could provide good alternatives for managers to refine development plans and have more assertive launch dates for new products. Our main contribution is empirical evidence of the comparative influence of product complexity and prototyping manufacturing on time prediction for NPD projects. Researchers can derive further investigations on mathematical modeling or the way to calculate input variables.

Development of spacer warp knitted thermoelectric generators

The research presented in this paper was aimed at developing spacer warp knitted thermoelectric generators (TEGs), which can generate electrical current from waste heat. Hence, this paper introduces a structural design approach and a calculation model in addition to describing the manufacturing of prototypes and analyses on their basic functionality regarding thermoelectric power generation. Wires as well as wire strands of iron and constantan can be used for knitting on a double bar raschel machine. Wires can be connected to a thermocouple (TC) by means of various spacer warp knitting patterns while using the feed system of the spacer yarn for the wires. The friction locking electrical contacting of several TC, thus forming an applicable TEG, was achieved by sewing together silver plated copper wire strands. A large wire cross section, clear separation of iron and con-stantan wires in the knitted fabric, and consistently high temperature difference between the TEG surfaces produce a constant thermoelectric voltage. The maximum voltage depends on the number of TC, the material properties, and the temperature difference. By reducing the internal resistance of the TEG, electric power can be increased.

Acoustic Optimization of a Power Take-off Gear Box Using Numerical Transfer Path Analysis

In this contribution, a method is proposed which allows for a target-oriented structural optimization of drive train systems using transfer path analysis on a multi body system simulation with respect to the airborne sound. It combines the existing approaches of multi body simulation (MBS) and experimental transfer path analysis (TPA) with sound radiation calculations thereby creating a new tool chain to not only identify critical operation points but also critical transfer paths of an MBS model. This approach combines the advantages of elastic MBS (i.e. information about modes and forces acting between different components in critical operating points) with the advantages of TPA (i.e. identifying critical paths from the excitation to the receiver) thereby enabling the designer to numerically deduct and evaluate target-oriented structural optimizations already in early stages of the development process. It therefore reduces development times and costs by reducing iteration loops and the manufacturing of physical prototypes. The method is demonstrated on a power take-off (PTO) gear box, of which the sound pressure level was reduced by 6 dB within three virtual optimization loops that each only take a few hours by applying the proposed method.

Polymerization mechanisms initiated by spatio-temporally confined light

Abstract Ultrafast laser 3D lithography based on non-linear light–matter interactions, widely known as multi-photon lithography (MPL), offers unrivaled precision rapid prototyping and flexible additive manufacturing options. 3D printing equipment based on MPL is already commercially available, yet there is still no comprehensive understanding of factors determining spatial resolution, accuracy, fabrication throughput, repeatability, and standardized metrology methods for the accurate characterization of the produced 3D objects and their functionalities. The photoexcitation mechanisms, spatial-control or photo-modified volumes, and the variety of processable materials are topics actively investigated. The complexity of the research field is underlined by a limited understanding and fragmented knowledge of light-excitation and material response. Research to date has only provided case-specific findings on photoexcitation, chemical modification, and material characterization of the experimental data. In this review, we aim to provide a consistent and comprehensive summary of the existing literature on photopolymerization mechanisms under highly confined spatial and temporal conditions, where, besides the excitation and cross-linking, parameters such as diffusion, temperature accumulation, and the finite amount of monomer molecules start to become of critical importance. Key parameters such as photoexcitation, polymerization kinetics, and the properties of the additively manufactured materials at the nanoscale in 3D are examined, whereas, the perspectives for future research and as well as emerging applications are outlined.

Metal Additive Manufacturing for the Rapid Prototyping of Shaped Parts: A Case Study

Metal Additive Manufacturing for the Rapid Prototyping of Shaped Parts: A Case Study

STAR laboratory at Politecnico di Torino: a facility to develop educational space projects

The hands-on practice programmes in technical universities provide a relevant value added for the students’ careers because allows them to create hard and soft skills, training them through real and complex projects. In this sense, the STAR Team of Politecnico di Torino operates in order to prepare students for their future works. Students are the backbone for any activity of educational projects that are ongoing since 2008 (and before). The hands-on practice activities are strongly supported by STARLab facilities and tools developed to support the development of space mission for the entire product lifecycle. The present paper shows how the STARLab activities: development, verification and operations of end-to-end missions of small satellites (mainly Cubesats), development and validation of tools and test benches for mission analysis, system and subsystem devices design, manufacturing and testing of prototypes, dummy models, and flight units are presented.

Design and additive manufacturing of brushless electric motor components

The electric motor components are manufactured through the additive process of fused filament fabrication in order to verify the functionality of the electric motor assembly. This process was chosen due to the advantages it confers: fast obtaining of components, low manufacturing costs, no tools required for processing or for moulds manufacturing. Through the fused filament fabrication process, parts with complex geometries, which cannot be obtained by classical machining, can be manufactured. Due to the above-mentioned advantages, this technology is extremely useful for the manufacture and testing of prototypes. The paper aims to manufacture components of a brushless electric motor in order to verify the assembling compatibility and manufacturing accuracy.

Method for calculating technical characteristics and parameters of movement of scale models of wheeled vehicles, ensuring the similarity of the processes during testing

Nowadays, when designing new vehicle models, there is a need to test certain solutions for the formation of a technical appearance both by simulation methods and on production samples. Full-scale road tests of vehicles make it possible to maintain full dynamic similarity during the experiment, but they can be carried out only after manufacturing of a vehicle prototype, which requires a lot of material costs. One of the ways to solve this problem is to create models that are a reduced copy of the designed vehicle. The main difficulty that appears when testing a scale model of vehicle is the need to accurately reproduce the conditions that occur when driving in real road conditions. The purpose of this paper is to find a relationship between the parameters of a production vehicle and a scale model for experimental development of algorithms for the dynamic stabilization of a wheeled vehicle. A method for calculating the technical characteristics and motion parameters of scale models for real full-scale wheeled vehicles while ensuring the similarity of the ongoing processes for scale models and for production vehicles is proposed on the basis of the theory of similarity. The main dependences for scale factors for force, kinematic and dimensional factors are obtained. The similarity of the occurring processes was confirmed by the methods of simulation modeling of the movement of a scale model and a full-scale wheeled vehicle.

Design of a composite nose wheel for commercial aircraft

Innovative approaches for lightweight design of components can contribute significantly to reduced fuel consumption and emissions of future aircraft. Within the framework of the European aviation research program Clean Sky 2, an innovative design of an aircraft nose wheel for the A320 is developed using carbon fiber reinforced plastics (CFRP) in order to demonstrate a weight reduction potential of 27% compared to conventional designs. In the present paper, the approach of the development process and the final detailed design of the composite aircraft wheel as well as a manufacturing concept are presented, various design challenges are highlighted and the solutions developed to meet them are discussed. Within a concept phase different structural design principles for the wheel are analyzed, taking into account the challenging load cases during different phases of aircraft operation. The selected innovative design principle is further elaborated into a detailed design considering design challenges such as space, installation, and safety requirements, as well as integration of bearings, seals and joint solutions. Also, structural analysis of the composite components via FEA and experimental validation of the joints are discussed. In addition, the manufacturing concept for the complex wheel geometry via resin transfer molding (RTM) using carbon non-crimp fabrics is presented and an outlook on the future manufacturing and testing of wheel prototypes is given.