Ivan Prebil

3D road traffic situation simulation system

The 3D traffic situation simulation system combines the multibody based mathematical model of a vehicle, the multibody mathematical model of human body, the database of vehicle and human body data and the display subsystem. Together with the model of driving surface the system can be used to simulate and analyse vehicle and its occupant behaviour under different road conditions and different driving regimes. The result obtained this way can be used to investigate safety related parameters and optimise the driver-vehicle-road system regarding to arbitrary criteria (safety, comfort, speed, etc.). The results of simulations are available as numerical data as well as animations in virtual 3D environment.

Minimum mesh design criteria for blast wave development and structural response - MMALE method

The Multi Material Arbitrary Lagrange Euler (MMALE) method is widely used method for numerical investigation of structural response under blast loading. However the method is very demanding for use at the other hand. In this paper are presented the results of the detailed numerical investigation in order to simplify some decisions contributing to the accuracy and efficiency of this model. The influence of mesh properties (particularly mesh size, its biasing and distance of the boundary (DoB) conditions from the deforming structure) on blast wave loading parameters and structural response is investigated in detail and based on the results minimum mesh design criteria is proposed. The results obtained are presented as a function of the scaled distance and additionally related to the radius of the charge. Validation studies were also done successfully.

i3Drive, a 3D Interactive Driving Simulator

i3Drive, a wheeled-vehicle simulator, can accurately simulate vehicles of various configurations with up to eight wheels in real time on a desktop PC. It presents the vehicle dynamics as an interactive animation in a virtual 3D environment. The application is fully GUI-controlled, giving users an easy overview of the simulation parameters and letting them adjust those parameters interactively. It models all relevant vehicle systems, including the mechanical models of the suspension, power train, and braking and steering systems. The simulation results generally correspond well with actual measurements, making the system useful for studying vehicle performance in various driving scenarios. i3Drive is thus a worthy complement to other, more complex tools for vehicle-dynamics simulation and analysis.

Object-oriented environment for design and production preparation of large rolling rotational connections

Abstract The article describes the programme environment that provides help to the designer with the design process of new types of large rolling rotational connections and supplements him with the expert system and built in algorithms for dimensioning and optimising the composing parts. The programme environment enables rapid transfer of new knowledge from the field of design and production technologies into the industry. It also enables typification of commonly used types of rotational connections and automates the procedures of production preparation. Object-oriented programming technique enables a user-friendly interface and connections with commercial CAD, FEM and CAM packages. The article also describes the proprietary expert system, founded on the object-oriented paradigm and graphical representation of the knowledge base. Operation of the expert system is represented in different phases of the design process, production of technical documentation and preparation of CNC technology.

Failure Properties and Damage of Cervical Spine Ligaments, Experiments and Modeling

Cervical spine ligaments have an important role in providing spinal cord stability and restricting excessive movements. Therefore, it is of great importance to study the mechanical properties and model the response of these ligaments. The aim of this study is to characterize the aging effects on the failure properties and model the damage of three cervical spine ligaments: the anterior and the posterior longitudinal ligament and the ligamentum flavum. A total of 46 samples of human cadaveric ligaments removed within 24-48 h after death have been tested. Uniaxial tension tests along the fiber direction were performed in physiological conditions. The results showed that aging decreased the failure properties of all three ligaments (failure load, failure elongation). Furthermore, the reported nonlinear response of cervical ligaments has been modeled with a combination of the previously reported hyperelastic and damage model. The model predicted a nonlinear response and damage region. The model fittings are in agreement with the experimental data and the quality of agreement is represented with the values of the coefficient of determination close to 1.

System for interactive scientific driving simulation with haptic information

An interactive wheeled vehicle simulator is described, consisting of a software application for simulating vehicle dynamics and presenting the results in virtual 3D environment, and a haptic interface. The latter consists of a hydraulically actuated active seat and an electrically activated active steering wheel. The system makes it possible to simulate wheeled vehicles of various configurations on arbitrary terrains. The design of the system is presented and the specific considerations are discussed. The system was experimentally verified by measurements on a real off-road vehicle. The kinematic values measured on the real vehicle and those, measured on the haptic interface were compared. The results are discussed and are generally found to correspond well, making the system usable for studying vehicle performance and training its operators.

Creating models of road sections and their use in driving dynamics simulations

The paper describes a system for measuring road section parameters in a way that the results can be used in driving dynamics simulations. The system consists of sensorics and a data acquisition subsystem supported by software for generating 3D road section geometrical models. These models are then used as driving surfaces in dynamics simulation packages to investigate and analyse different aspects of road design and its role in traffic accident analysis, reconstruction and prevention. The paper presents examples of measurements, road section modelling and simulation results, obtained by means of different software simulation tools. It discusses possibilities of further development and improvement of the system.

Parametric analysis study of blast loaded armour V-plates

Continuous improvement in the hull floor of light armoured vehicles in terms of landmine response and crew safety is required among other things, in order to meet higher demands in the market and to obtain a product safety certificate. Previous research studies have shown that V-shaped hull floors of light armoured vehicles have a better response to blast loading in terms of saving the lives of vehicle crews or reducing the number of injuries. For this reason, parametric and design optimization analyses of V-shaped hull floors play an important role in achieving an optimal, safe and cost-effective light armoured vehicle design. However, this kind of structural optimization is complex, involving a multidisciplinary fluid–structure interaction processes, as well as large structural deformations. This article presents the results of the metamodel-based parametric analysis of blast loaded armour V-plates. The contribution of most important variable parameters such as plate angle, plate thickness, explosive mass and stand-off distance to blast loading and blast response parameters was examined using a combined smooth particle hydrodynamic – finite element numerical model. The results showed that the plate angle has the greatest impact on all response parameters of the metamodel, followed by the stand-off distance and plate thickness.

Comparative study of European tunnel emergency-stop-area-wall protection measures

Due to the increasing number of traffic accidents involving the collisions of vehicles with the emergency-stop-area head walls in tunnels, a comparative numerical analysis in accordance with the EN 1317 standard has been performed in order to assess the quality of the available protective safety barriers. Based on the simulation results, the values of the relevant injury criteria - the acceleration severity index (ASI), the theoretical head impact velocity (THIV) and the post-impact head deceleration (PHD) - were computed for several collision scenarios involving two different passenger vehicles colliding with two different safety barriers in various ways. The results show that due to the geometrical restrictions in the tunnels emergency stop area none of the barriers can provide total protection for the occupants of the vehicle in the event of a collision. The installation of a steel-sheet-tube crash cushion was, however, found to provide the best possible protection within the given limitations. The results of the analysis were the basis for selecting a safety-barrier design for existing tunnel installations and for the proposed changes in regulations governing the geometry of the tunnels emergency stop area.

C11 Biomechanische Daten

Die Analyse von Verkehrsunfallen mit Personenbeteiligung erfordert eine umfassende Behandlung, bei der mehrere wichtige Gesichtspunkte berucksichtigt werden mussen. Bei Verkehrsunfallen beteiligte Personen sind meistens Fahrzeuginsassen, im geringeren Mase auch Fusganger oder Benutzer anderer Verkehrsmittel.