Shape optimization is a way to improve the structural performance of components and tools based on parametric geometries are becoming standard for fine-tuning optimization in industry. Direct update of nodal positions of finite element models by mesh morphing is a meaningful alternative to re-meshing a parametric geometry, helping the designer in what-if studies, optimization and robust design development without geometry coherence problems. There are some cases where FE loads depend on the geometric features on which they are applied or, on the other side, the analyst could want to strictly control the geometric features of the component.
Geometry features can be controlled with mesh morphing, but in general, it is much easier and intuitive to direct control them with parametric geometries. On the other side geometry coherence can be a too strong limitation that inhibits any optimization of it. A different approach to mix the goods of both the techniques and overtake their limitations is proposed together with its application. The proposed methodology is based on the main idea that the optimization is a mesh-based optimization driven by a parametric geometry. ModeFrontier potentialities are exploited to manage the optimization loop while RBF Morph is used to perform mesh morphing. Thanks to the proposed methodology different shapes can be obtained and analyzed according to internal procedures in order to speed up the design selection process.
Multi-objective optimization of a transmission system for an electric counterbalance forklift
Marco Ricci, Bonfiglioli Riduttori
Andrea Torcelli, Bonfiglioli Riduttori
The optimization of a planetary gear train arrangement or even single gear pair, included in a complex transmission system can be fairly complicated mainly because it involves a high number of input variables as well as multiple objectives which are often in contrast with each other. This paper describes the implementation of a process which would allow to optimize the design of a helical gears pairs using a multi-objective optimization platform coupled with a calculation software for design of rotating machinery and gears.
With the specific focus to reduce the noise related to the gear meshing, a combined objective function which maximizes
the transverse contact ratio and the overlap ratio, and minimizes the transmission error has been considered in this model, always imposing acceptable stress values on the teeth. The model has been validated by means of experimental measurement on the actual machine where the results have been compared with those related to the actual solution, in which the pair of the first stage gears are designed with traditional methods.
This full presentation is not available
Ingersoll Rand Italiana
The SAFE Interference Diagram for compressor impeller design with ANSYS Workbench
Open impellers are the main rotating components in centrifugal compressors and their structural integrity and safety are crucial characteristics in the operative success and safety of the machine itself. Stress and modal analyses are the basis for a good structural design of impellers. While a static structural analysis guarantees the assessment within mechanical material limits in steady-state condition, particular attention has to be paid in the pre-stressed modal analysis that permits to identify the harmonic frequencies of the bladed disk and consequently to evaluate the possible resonant excitation to avoid vibration-related failure, due to the dynamic stresses.
The Singh’s Advanced Frequency Evaluation (SAFE) Interference Diagram is an important tool that allows to combine the impeller natural frequencies, the disk mode shapes, the operative speed range and the excitation frequencies in the same graph, providing a complete overview of the system behavior. The aim of this paper is to describe the SAFE Interference Diagram and its parameters and to illustrate the results of a pre-stressed modal analysis performed on an impeller with ANSYS Workbench.
How to optimize an external gear pump in highly constrained conditions
Antonio Lettini, Casappa
Today any kind of hydraulic subsystem has to guarantee high performances and reliability in order to match customer challenging requests. Furthermore, it is required to reduce price and time-to-market of new products. During the last years optimizations through simulation tools have become the standard to be competitive and fast enough. In this context it is not unreal to think that reducing the optimization time and increasing the optimization quality will become more and more important in the nearest future. This paper will show an example of how a new external gear pump can be optimized to achieve best performances in terms of efficiency, pressure pulsations and noise emission.
Since the expected performances are always higher in respect to previous versions, while complying production needs, this kind of problem becomes highly constrained. A comparison between optimization results obtained with two different modeFRONTIER algorithms will be shown: it will be pointed out how much important is to choose the algorithm that best suits to the specific application in order to find the lowest Pareto frontier in the lowest computational time.
Optimization of an automotive manufacturing system design taking into account regional requirements
Marcello Colledani, Politecnico di Milano, Dipartimento di Meccanica
Andrea Ratti, Politecnico di Milano, Dipartimento di Meccanica
Anna Bassi, Francesco Micchetti, Giovanni Borzi, EnginSoft
Simone Belardinelli, COMAU Spa
The design of automotive manufacturing systems is a core competence of COMAU, and represents a complex task that relies heavily on knowledge and experience. COMAU is continuously improving its manufacturing systems design processes in order to reduce the design lead times, shorten the time to market and increase the “first time right” designs. Results presented in this work are grounded on a novel approach to the preliminary design of production systems, capable of taking into account engineering and throughput constraints, equipment and lifecycle costs, and including region-dependent parameters such as local energy and personnel costs.
This approach enables the system designer to automatically generate and evaluate hundreds of different alternative manufacturing system designs, obtain the Pareto frontier, and subsequently select and validate the optimal ones. Acknowledgment: the ProRegio - Customer-driven design of product-services and production networks to adapt to regional market requirements - project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 636966.
Gear Lubrication and Efficiency Predictions: a new Mesh-Handling Algorithm to Reduce the CFD Simulation Time
To improve the efficiency of geared transmissions, prediction models are required. Literature provides only simplified models that often do not take into account the influence of many parameters on the power losses. Recently some works based on CFD simulations have been presented. The drawback of this technique is the time demand needed for the computation. In this work a less time-consuming numerical calculation method based on some specific mesh-handling techniques was extensively applied. With this approach the windage and the churning phenomena were simulated and compared with experimental data in terms of power loss and lubricant fluxes.
The comparison shows the capability of the numerical approach to capture the phenomena that can be observed experimentally. The powerful capabilities of this approach in terms of both prediction accuracy and computational effort efficiency make it a potential tool for an advanced design of gearboxes as well as a powerful tool for further comprehension of the physics behind the gearbox lubrication.
Simplifying Machine Design with System-Level Modeling Technology
This presentation will show how Maplesoft’s Engineering Solutions team provided a platform for examining the dynamic behavior of a Lifted Radial Stacker, a complex machine used for material handling in mines.
As stability and weight distribution are key considerations in the design of such machines, engineers at FLSmidth required a multi-domain dynamic model of the Lifted Radial Stacker. Maplesoft’s Engineering Solutions team developed a model of the complex machine in MapleSim, providing engineers with a virtual environment to apply multiple approaches to evaluate dynamic response of the system.
This full presentation is not available
Gear box lubrication pattern analysis with Moving Particle Simulation in Particleworks
A two speed reduction gear box has been used in a case study to evaluate if the MPS method can replace expensive and time consuming lab tests.
The gear box is a part of the rotor drive transmission chain of a forage harvester machine and works in a very wide range of rotational speed and torque. A good lubrication for all rotating component is mandatory to avoid failures and overheating issues.
The goal has been to calibrate the MPS model parameters in order to fit the oil physics in the experimental lab tests of the same gear box. After the calibration phase, geometry changes are made and a new oil level is defined to see the effect on lubrication and on churning losses.
The MPS method proved to be successful in predicting performance of a tailored gear box and in reducing lab tests. The physics of free surface flow and splashing phenomena of the oil are accurately captured with the MPS method. Moreover the modelling and simulation time is low compared to traditional CFD methods, so that the MPS simulations fit in the product development process.
Optimization of Efficiency of Filter for Decontamination using MPS Particle Method
Hiroyuki Kase, Prometech Software Inc.
In the manufacturing processes such as glass and ceramic processing, precision casting processing and blast polishing, various sludge gets mixed into working fluid. If sludge is not filtered out from the working fluid sufficiently, it may cause many troubles, e.g., scratch on the surface of products, deficiency in forming precision, lifetime shortening of grinder and so on. As the result, production cost increases. In these precision machining processes, it is crucial to decontaminate working fluid using high performance filters. For this purpose, improvement of decontamination efficiency of a cylinder shape filter was investigated using simulation. Dirty water flows into the filter system from the inlet placed at the bottom of the case and it flows through the cylinder shape filter.
At this moment sludge is absorbed on the surface of the filter and the purified water flows out from the filter system through the outlet at the top of the case. The purpose of this study is the optimization of the efficiency of the filter system. Shape optimization of the filter system was performed using MPS particle method based CFD software Particleworks and filtering performance was improved dramatically.
The study of the development of Consumer Price Index and Producers Price Index in OECD countries, it demonstrates that there is an imbalance between price and cost development. This situation has created a productivity gap that presents a challenge for many companies.
One key opportunity to close this productivity gap is during the purchasing of machines or tools ecc. In this paper we’re going to review the process and row material and to show what Sandvik can do to close this negative productivity gap. Productivity is a chain where the rings are: Material ,Machine tool, Tools
Methods ,Knowledge , CNC. We will analize the influence of the material to improve productivity and reducing costs We’ll start with the presentation of the stainless steel material duplex , superduplex hyperduplex, from mechanical and chemical characteristics of bars and hollow bars manufactured by Sandvik.
The analysis of the process of manufacturing Sandvik Material Technology will lead us to define the various passages from the casting and melting through rolling forging extrusion to the heat treatment. We will focus in particular on the methodology of production of steels SANMAC (high machinability). Following the illustration of the characteristics of steels SANMAC defining the advantages and disadvantages of these products.
The central part of the presentation will report the results obtained from tests performed on our material superduplex 1.4410 compared with an equivalent of a competitor. In the test are considered the tool life of the cutting edge at different cutting speeds (60-125m/min), the chip control with different parameters, the surface finishing and power consumption The tests were carried out in turning, drilling, tapping and parting off. Following the results it is assumed the realization of a piece whereas the two starting materials. We will calculate the cost of production and will allow us to quantify the savings achievable by a material with the best machinability. We will also consider the use of hollow bar for the realization of the same piece. Again we are going to compare the cycles and the analysis of the times and costs will lead us to draw conclusions about the possibility of using this solution. The conclusion will be a pratical and interesting reduction of the final cost and improving the productivity
Object of Optimization:The centrifugal pump of the mining dump. This pump is using in the engine cooling system. Goal of Optimization: It is necessary to find the optimal geometry of blades and the optimal quantity of blades to increase the pump efficiency. Parameters of Optimization: Geometrical structure of blade.
Coupled CFD-combustion simulations for glass melting furnaces design
Nicola Parolini, MOX, Politecnico di Milano
Alessandro Mola, Stara Glass
Reacting combustion, turbulent flows and thermal exchange mechanisms are only few of the coupled physics governing the glass melting process in industrial furnaces. The comprehension of such complex phenomena is mandatory to design furnaces respecting the high standard quality required by the glass market, keeping energy consumption at bay and fulfilling the strict EU NOx pollutant regulations. Numerical simulations based on advanced models accounting for the coupled physics are an ideal tool to achieve these goals.
In this work, Moxoff presents a multiphysics CFD simulation framework modelling the combustion process in glass furnaces developed for StaraGlass, an Italian SME producer. The advanced coupled numerical model is implemented in a standard and automated simulation workflow based on open-source software. This provides engineers, even if not experts in simulations, with an accurate and flexible tool to support furnaces optimal design and operating scenarios.
Virtual Drop Test and Falling Object Test on Safety Remote Control
Valerio Caputo, EnginSoft
Autec Safety Remote Control is an Italian company leader in the design and manufacturing of wireless radio remote controls for industrial/construction cranes and mobile machinery for off-highway applications. Autec improving processes are guided by 3S principle, i.e. excellence in Safety, Solutions and Service EnginSoft helps Autec on each ‘S’ using LS-DYNA.
Safety: LS-DYNA has been used to simulate drop tests and falling object tests to help engineers to choose the best solution to guarantee a good resistance of the Remote Control that can operate amid challenging circumstances on highly demanding environments Solutions: simulations, introduced in the early phase of the concept design, help Autec to choose the most efficient design and the best material for specific customer needs. A well correlated FEM avoid to build up many prototypes and to do many physical tests reducing R&D costs and time development product.
Service: Autec believes that customers are the lifeblood of any business, so it is important to place an emphasis on the customer experience both before and after a sale is made. The simulations is one of the tools used to reach this objective and it helps Autec to create “Customers for Life” by the design of reliable products
Volume-of-Fluid and Particle-based Methods for Predicting Churning Losses of Spur Gears
Michael Ehlen, qpunkt GmbH
Hua Liu, M.Sc., Gear Research Centre (FZG), Technical University of Munich
Dipl.-Ing. Thomas Jurkschat, Gear Research Centre (FZG), Technical University of Munich
Thomas Lohner, M.Sc., Gear Research Centre (FZG), Technical University of Munich
Prof. Dr. Karsten Stahl, Gear Research Centre (FZG), Technical University of Munich
The demand for further efficiency enhancements of current transmission systems and gearboxes makes it inevitable to investigate no-load power losses that can contribute a considerable portion to the overall losses of gear drives. Especially, current developments of ultra-high-speed drive systems require the optimization of windage and churning losses, which can have significant impact on the performance of lubricated systems. Unfortunately, current analytical and empirical approaches for no load gear losses often provide poor results with high deviation compared to measurements, particularly for operating conditions beyond the validity of the approaches.
CFD methods offer a high potential to investigate the no load power losses with a much higher quality than current empirical equations. However, few works have been able to successfully validate their approaches for multiphase models with experimental results yet. In a first step, this study employs a Volume-of-Fluid-based approach to model the churning losses of a dip-lubricated spur gear pair in the gearbox of the FZG back-to-back gear test rig. The rotation of the gear pair is realized through overset meshes, which allow a realistic representation of the meshing of the gear pair.
In a second step, we investigate the possibility to model the churning losses with a state-of-the-art particle-based method (ISPH), which promises a significant reduction in preparation and computation time.
Both simulation methods were compared to experimental data measured with a standardized FZG-back-to-back gear test rig at the Gear Research Centre (FZG) of the Technical University of Munich.
Finally, a summary of the results and an outlook to future developments and the potential applicability of the methods are given.
Design and Analysis of a MEMS-Based Electrothermal Microgripper
Pierluigi Mollicone, University of Malta
Ivan Grech, University of Malta
Bertram Mallia, University of Malta
Nicholas Sammut, University of Malta
Microelectromechanical systems (MEMS) have established themselves in various science and engineering domains. MEMS-based microgrippers provide several advantages in terms of compact size and low cost, and play vital roles in microassembly and micromanipulation fields within both micromanufacturing and biological sectors. Microactuators based on different actuation principles have been devised to drive MEMS-based microgrippers.
This paper presents a finite element model of a MEMS-based electrothermally actuated microgripper performed using CoventorWare®. The microgripper design follows standard micromachining processes that make use of reactive ion etching (RIE) where polysilicon acts as the main structural material while a gold layer is deposited on the structure for thermal actuation. The simulations are used to assess the performance of the microgripper and to optimize its operating parameters.
Multiple results compression techniques in μETA PostProcessor
One of the key issues in CAE world is the storage of the large amount of data that are being generated. As models are progressively increasing in size and the calculation time decreases rapidly due to solver improvements and higher processing power, the amount of derived data is proliferated and thus, storage becomes an important concern that must be confronted. On the users side, big result files are always related to longer idle times since transferring these files over a network and load them on a post-processor can take considerable time. On top of that, in most of the cases, the actual data that need to be stored represent just a small percentage of the total content of a result file thus minimising, if not removing at all, any possible benefit from keeping the total amount of data. In order to address this issue in an efficient way, BETA CAE Systems initiated the development of several techniques that have been embedded in μETA, the cross-discipline post-processor of the BETA CAE Systems suite for FEA and CFD analysis. Selected results can be saved in a native binary format either uncompressed or compressed. Compression can be either lossless or lossy, the latter offering the biggest advantage since it can achieve compression ratios of up to 90% or more. However, in that case, the provided full control on the accuracy level per type of results as well as per part or group, allows for exploiting the maximum benefit from the compression without compromising the accuracy in model areas of interest. Compression for large CFD models can be further augmented through the simplification of solids for non-important areas. In parallel to minimising the storage needs through jointly applying the above compression techniques, a significantly higher reading performance is realised.
This paper presents in detail these compression techniques and the results from comparative studies conducted for different models.
Efficient implementation of the BST shell for multi-flexible-body simulations
Alessandro Tasora, University of Parma
Nowadays, a wide choice of finite element formulations is available, not only within the academia, but also in ready-to-use commercial software, covering very different case scenarios. Many of these are suited to capture high-order behaviors or to fit complex shapes (e.g. isogeometric elements) but, because of their complexity, are not always the best choice for large-scale simulations or for entangled non-uniform shapes. For these latter cases, a finer mesh of less computational demanding elements is often a better choice.
In this context, the Basic Shell Triangle, a rotation-free triangular element based on Kirchhoff–Love theory, has been implemented in the multibody simulation software Chrono::Engine, taking into account different approaches already proposed in literature . Lacking of rotational degrees of freedom, the curvature of this element cannot be directly inferred from the (linear) displacement field, giving rise to a more code-involved implementation that has to consider also the state of neighboring elements.
This full presentation is not available
Verification and optimization of a Roller Coaster
Luca Catellani, Asotech
Giovan Battista Trinca, Asotech
Pietro Ghillani, Asotech
Asotech is proud to present some of the solutions that it has developed for the world of Amusement Rides. For many years, Asotech has devoted particular attention to ROLLER COASTERS with passion and competence applied to the calculation, to the structural verifications, and to their design.
Starting from the structural verifications carried out in the ANSYS environment and Straus7, Asotech has developed specific software tools for the kinematic and dynamic verification of the chosen trajectory given by CAD or NO LIMITS software. The program has been validated against the most advanced multibody software available on the market.
Asotech will demonstrate its working procedure, placing particular emphasis on the dynamic and kinematic verifications that support the design and sizing of, what is, one of the most complex feats of engineering.
The structural verification of the space frame of the ride is carried out within Straus7 and ANSYS Workbench environment: a fatigue verification of the main welding joints following Eurocode 3, and an optimization of the beam sections in order to minimize material wastage, are included.