Michal Fabian

Computer modelling of wire strands and ropes part II: Finite element-based applications

In the comparison with the theoretical analyses of wire strands reported in the literature where obviously single-layered strands with a construction of the 1+6 wires were modelled and analysed, this paper is focused on a multi-layered strand with a construction of the 1+6+12+18 wires. The geometric parametric equations developed in the first part of this paper [1] are implemented in CATIA V5 software code for geometric modelling of the multi-layered strand. The methodology of their implementation and the approach for the generation of the strand geometric model are demonstrated. To predict the behaviour of the multi-layered strand under tensile loads, the mathematical geometric model is further implemented in a finite element program. For this purpose ABAQUS/Explicit software is used. The derived 3D geometric models of the multi-layered strands and the results of the finite element elastic behaviour analyses of the strand under tension loads are validated through comparisons with experimental and theoretical data available. The results obtained confirm the correctness of the derived parametric equations and mathematical and physical importance of the finite element model developed.

Computer modelling of wire strands and ropes Part I: Theory and computer implementation

In this paper the mathematical geometric models of the single-lay wire strands and double-lay wire ropes with defined initial parameters are presented. The present geometric models fully consider the single-helix configuration of individual wires in the strand and the double-helix configuration of individual wires within the wound strands of the ropes. The mathematical representation of the single and double helixes is in form of parametric equations with variable input parameters which determine the centreline of an arbitrary circular wire of the right hand lay and left hand lay strands and ropes of the Lang lay and regular lay construction. The concrete forms of the parametric equations are derived and presented. The application of the derived geometric analytical model is illustrated by numerical examples. Techniques for the implementation of the derived mathematical models in CATIA V5 software and procedures for the generation of the rope model are briefly presented. Correctness of the derived parametric equations and a performance of the generated rope model are controlled by visualizations. The application of the derived mathematical model and the development of a finite element model for the numerical simulation of the multi-layered strand under tension tests are treated in the second part of the paper [1].

Finite element analysis of spiral strands with different shapes subjected to axial loads

A new mathematical geometric model of spiral oval wire strands is proposed.Concrete forms of derived parametric geometric equations are presented.Results of FE analyses of four spiral strands with different shapes are presented.Responses of round, triangular and oval strands under axial loads are compared.Result ant stress and/or deformation behaviours are discussed. In this paper a new mathematical geometric model of spiral one or two-layered oval wire strands are proposed and an accurate computational two-layered oval strand 3D solid model, which is used for a finite element analysis, is presented. The three dimensional curve geometry of wires axes in the individual layers of the oval strand consists of straight linear and helical segments. The present geometric model fully considers the spatial configuration of individual wires in the right and left hand lay strand. Derived geometric equations were used for the generation of accurate 3D geometric and computational models for different types of strands. This study develops 3D finite element models of two-layer spiral round, triangular and oval strands subjected to axial loads using ABAQUS/Explicit software. Accurate modelling and understanding of their mechanical behaviour is complicated due to the complex contact interactions and conditions that exist between individual spirally wound wires. Comparisons of predicted responses for the strands with different shapes and constructions are presented. Resultant stress and/or deformation behaviours are discussed.

Influence of the CAM Parameters and Selection of End-Mill Cutter when Assessing the Resultant Surface Quality in 3D Milling

The paper deals with the effects of CAM data needed to produce desired quality of shaped surfaces in forming dies making. In general, the input CAM data have strong influence to the final surface quality. The shaped surfaces 3D milling has been modeled as end ball milling of the surfaces with defined inclination. The end ball milling is the most common way to finish shaped surfaces. Directions of the milling tools motion and applied cutting conditions have been used to simulate data when setting milling strategies. The resultant machined surface quality has been identified in terms of the surface roughness. The paper introduces recommendations applicable to the programming of the different types of milling strategy when producing form surfaces.

Design of experimental vehicle specified for competition Shell Eco-marathon 2017 according to principles of car body digitisation based on views in 2D using the intuitive tool Imagine&Shape CATIA V5

Shell Eco-marathon and Building of Experimental Vehicle.Intuitive Tool for Creation of Surface Model in CATIA V5.Design with Imagine&Shape.Rapid Prototyping.Aerodynamics analysis. Materialisation of every new great idea requires performing of many activities, including application of the latest CA-technologies. Nowadays the design process concerning the exterior and interior parts of a motorcar is unthinkable without utilisation of the CAD support. Although the primary impulses, new ideas or inspirations are arising in the minds of customers, businessmen and managers, the realisation process itself is always a serious task for the engineers in order to create a final shape, taking into consideration the customers requirements. The experimental vehicles represent a special category of the motorcars. Design of the experimental vehicles demands a specific approach with regard to the above-standard requirements concerning vehicle aerodynamics, reduced rolling resistances and low-level fuel consumption of the vehicle engine.

Principles of car body digitisation based on geometry extracted from views in 2D drawing documentation

Application of the computer aided design (CAD) systems reduced duration of innovation cycle in the area of new motorcar development from 8-10 years in the past to 4-6 years presently. Another consequence of the CAD implementation is a fact that some of simpler modifications of the car body shapes, i.e., the so-called facelifts, are applied already two or three years after the beginning of a new model production. With regard to a fact that the motorcar is a result of mutual cooperation between the designer and constructor, the designers ideas are impressed into the modelling material (clay) or they are presented on paper in the form of sketches. The next step is already up to technicians, i.e., they have to transform these ideas into the real 3D data fields in order to prepare tools for the production of the individual motorcar parts. This paper describes an example of exact modelling according to the drawing documentation.

Autonomous vehicle with internal combustion drive based on the homogeneous charge compression ignition technology

The actual dynamical development of the information technologies is also typical for the area of automotive industry. The autonomous control technology is moving the motorcars into the mobile robot category. The autonomous mobile robotic vehicles, together with new possibilities offered thanks to the mobility services, are improving not only comfort but also safety of transport. Nowadays, application of the homogeneous charge compression ignition technology represents a great progress made in the field of internal combustion drive, taking into consideration more and more rigorous emission standards. This article deals with principles and architecture of the autonomous control, with hybrid drive systems as well as it analyses advantages of the homogeneous charge compression ignition technology, taking into consideration the obtained experimental results.