On the Design and Life Prediction of Transmission Belts Made of Elastomer Composites

Next to gear transmissions, belt transmissions are the most important mechanical transmissions. Today, belt design and development is based on extensive application tests of belts in the product development process. There is a need for theory development and design support systems. This would enable simulation for prediction and optimization of fatigue life.The aim of this work is to study certain parts of the belt in detail when the belt is running under loaded conditions. The areas of special interest are those which can be related to failure mechanisms. Thus the model can be used for calculations to predict service life. Here, the attention is focused on V-belts. A fully three-dimensional finite strain constitutive model has been developed for the anisotropic elastomer composites used in V-belts and the constitutive model has been implemented into FEM-software. This makes it possible to do general stress and strain analysis of machine elements designed of elastomer composites. Several different failure modes can be identified in V-belt fatigue. Here it is shown that the failure modes thus defined occur for such test conditions that long life can be associated with radial cracks, medium life with separation, and cord break with short life. In order to monitor the stress-strain state at any location in the belt, while simulating a running belt, “the parametric belt segment model” has been developed. Correlation with V-belt fatigue data for 11 different load cases has been made.Our conclusion is that both failure mode and fatigue life can be predicted using computer simulations. Friction and wear of materials in a V-belt drive have also been studied

Transient conformal TEHL algorithms for multibody simulation

This article describes aspects of transient thermal elasto-hydrodynamical lubrication (TEHL) contact modelling for conformal contacts. This is to be utilized in a multibody simulation (MBS) framework for engineering purposes. The verification and proof of concept is done by implementation in the tool BEAST (Fritzson et al., 2014) and by comparision to published experiments and simulation results

Composite modelling in 3-D mechanics utilizing Transmission Line Modelling (TLM) and Functional Mock-up Interface (FMI)

Composite modelling and simulation is a solution to utilize investments in models and tools, use the right tool for the right task, increase the accuracy by means of more accurate modelled boundary conditions, switch between levels in model complexity for a specific sub-system, and facilitate co-operation in organizations. With the new Functional Mock-up Interface (FMI) standardization, efforts are increasing to make this happen. SKF BEAST is an advanced dynamic simulation tool for rolling bearings and other mechanical systems with contacts. The tool incorporates a framework for composite modelling and co-simulation, i.e., a Master Simulation Tool (MST). It uses Transmission Line Modelling (TLM) to ensure robust numerical behaviour of the complete composite system model and supports the Functional Mock-up Interface (FMI) for model import, including both model exchange and co-simulation. In this paper, the tools and the techniques for composite modelling are discussed in further detail and application examples are given

The OpenModelica integrated environment for modeling, simulation, and model-based development

OpenModelica is a unique large-scale integrated open-source Modelica- and FMI-based modeling, simulation, optimization, model-based analysis and development environment. Moreover, the OpenModelica environment provides a number of facilities such as debugging; optimization; visualization and 3D animation; web-based model editing and simulation; scripting from Modelica, Python, Julia, and Matlab; efficient simulation and co-simulation of FMI-based models; compilation for embedded systems; Modelica- UML integration; requirement verification; and generation of parallel code for multi-core architectures. The environment is based on the equation-based object-oriented Modelica language and currently uses the MetaModelica extended version of Modelica for its model compiler implementation. This overview paper gives an up-to-date description of the capabilities of the system, short overviews of used open source symbolic and numeric algorithms with pointers to published literature, tool integration aspects, some lessons learned, and the main vision behind its development.Fil: Fritzson, Peter. Linköping University; SueciaFil: Pop, Adrian. Linköping University; SueciaFil: Abdelhak, Karim. Fachhochschule Bielefeld; AlemaniaFil: Asghar, Adeel. Linköping University; SueciaFil: Bachmann, Bernhard. Fachhochschule Bielefeld; AlemaniaFil: Braun, Willi. Fachhochschule Bielefeld; AlemaniaFil: Bouskela, Daniel. Electricité de France; FranciaFil: Braun, Robert. Linköping University; SueciaFil: Buffoni, Lena. Linköping University; SueciaFil: Casella, Francesco. Politecnico di Milano; ItaliaFil: Castro, Rodrigo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Investigación en Ciencias de la Computación. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Investigación en Ciencias de la Computación; ArgentinaFil: Franke, Rüdiger. Abb Group; AlemaniaFil: Fritzson, Dag. Linköping University; SueciaFil: Gebremedhin, Mahder. Linköping University; SueciaFil: Heuermann, Andreas. Linköping University; SueciaFil: Lie, Bernt. University of South-Eastern Norway; NoruegaFil: Mengist, Alachew. Linköping University; SueciaFil: Mikelsons, Lars. Linköping University; SueciaFil: Moudgalya, Kannan. Indian Institute Of Technology Bombay; IndiaFil: Ochel, Lennart. Linköping University; SueciaFil: Palanisamy, Arunkumar. Linköping University; SueciaFil: Ruge, Vitalij. Fachhochschule Bielefeld; AlemaniaFil: Schamai, Wladimir. Danfoss Power Solutions GmbH & Co; AlemaniaFil: Sjolund, Martin. Linköping University; SueciaFil: Thiele, Bernhard. Linköping University; SueciaFil: Tinnerholm, John. Linköping University; SueciaFil: Ostlund, Per. Linköping University; Sueci

Using the Mathematica environment for generating efficient 3D graphics

Mathematica is an integrated environment for symbolic transformation of mathematical formulas. This environment has applications in scientific computing, scientific visualization and education. Mathematica gives possibility to describe visualized objects in form of mathematical formulas and expressions. Such descriptions are more clear and concise than low-level C or C++ code. Many visualization systems require input in the form of (sometimes huge) data files, which is a disadvantage for highly interactive and animated 3D graphics applications. This is also the case for graphics expressed in Mathematica which is computed interpretively and saved in a static data form before display. This causes low graphic performance. In this paper we describe an approach which uses object geometry descriptions in the form of efficient program code instead of huge data files. We have built a tool that produces 3D visualizations of geometrical objects and object trajectories from mathematical specifications expressed as parametric functions in Mathematica. A compiler has been developed which generates efficient C++ code from such functions and symbolic expressions. This code is linked together with a powerful 3D browsing environment and uses OpenGL with possible hardware support. All the computations are performed within the visualizing application. Object geometry, color, etc. can be changed dynamically during animations. Thus the flexibility of interactive exploration of 3D scenes and animation become available for the end-user

Lossless Compression of High-volume Numerical Data from Simulations

Applications in scientific computing operate with high-volume numerical data and the occupied space should be reduced. Traditional compression algorithms cannot provide sufficient compression ratio for such kinds of data. We propose a lossless algorithm of delta-compression (a variant of predictive coding) that packs the higher-order differences between adjacent data elements. The algorithm takes into account varying domain (typically, time) steps. The algorithm is simple, it has high performance and delivers a high compression ratio for smoothly changing data. Both lossless and lossy variants of the algorithm can be used. The algorithm has been successfully applied to the output from a simulation application that uses a solver of ordinary differential equations

Lossless compression of high-volume numerical data from simulations

Applications in scientific computing operate with high-volume numerical data and the occupied space should be reduced. Traditional compression algorithms cannot provide sufficient compression ratio for such kinds of data. We propose a lossless algorithm of delta-compression (a variant of predictive coding) that packs the higher-order differences between adjacent data elements. The algorithm takes into account varying domain (typically, time) steps. The algorithm is simple, it has high performance and delivers a high compression ratio for smoothly changing data. Both lossless and lossy variants of the algorithm can be used. The algorithm has been successfully applied to the output from a simulation application that uses a solver of ordinary differential equations.

Automatic Generation of User Interfaces from Data Structure Specifications and Object-Oriented Application Models

Applications in scientific computing operate with data of complex structure and graphical tools for data editing, browsing and visualization are necessary. Most approaches to generating user interfaces provide some interactive layout facility together with a specialized language for describing user interaction. Realistic automated generation approaches are largely lacking, especially for applications in the area of scientific computing. This paper presents two approaches to automatically generating user interfaces (that include forms, pull-down menus and pop-up windows) from specifications. The first is a semi-automatic approach that uses information from objectoriented mathematical models, together with a set of predefined elementary types and manually supplied layout and grouping information. This system is currently in industrial use. A disadvantage is that some manual changes need to be made after each update of the model. Within the second approach we have designed a tool, PDGen (Persistence and Display Generator), that automatically creates a graphical user interface and persistence routines from the declarations of data structures used in the application (e.g., C++ class declarations). This largely eliminates the manual update problem. The attributes of the generated graphical user interface can be altered. Now structuring and grouping information is automatically extracted from the object-oriented mathematical model and transferred to PDGen. This is one of very few existing practical systems for automatically generating user interfaces from type declarations and related object-oriented structure information. Published in Proceedings of European Conference on Object-Oriented Programming (ECOOP96), Linz, Austria, 8-12 July 1996, Pierre Coi..

Numerically robust co-simulation using transmission line modeling and the Functional Mock-up Interface

Modeling and simulation are important tools for efficient product development. There is a growing need for collaboration, interdisciplinary simulation, and re-usability of simulation models. This usually requires simulation tools to be coupled together for co-simulation. However, the usefulness of co-simulation is often limited by poor performance and numerical instability. Achieving stability is especially hard for stiff mechanical couplings. A suitable method is to use transmission line modeling (TLM), which separates submodels using physically motivated time delays. The most established standard for tool coupling today is the Functional Mock-up Interface (FMI). Two example models in one dimension and three dimensions are used to demonstrate how the next version of FMI for co-simulation can be used in conjunction with TLM. The stability properties of TLM are also proven by numerical analysis. Results show that numerical stability can be ensured without compromising on performance. With the current FMI standard, this requires tailor-made models and custom solutions for the interpolation of input variables. Without using custom solutions, variables must be exchanged using sampled communication and extrapolation. In this case, stability properties can be improved by reducing communication step size. However, it is shown that stability cannot be achieved even when using unacceptably small communication steps. This motivates the need for the next version of FMI to include an intermediate update mode, where variables can be interchanged in between communication points. It is suggested that the FMI standard should be extended with optional callback functions for providing intermediate output variables and requesting intermediate input variables.Funding: Vinnova within the ITEA OpenCPS projectOpenCP