No description available.

abstract: Composite materials are finally providing uses hitherto reserved for metals in structural systems applications – airframes and engine containment systems, wraps for repair and rehabilitation, and ballistic/blast mitigation systems. They have high strength-to-weight ratios, are durable and resistant to environmental effects, have high impact strength, and can be manufactured in a variety of shapes. Generalized constitutive models are being developed to accurately model composite systems so they can be used in implicit and explicit finite element analysis. These models require extensive characterization of the composite material as input. The particular constitutive model of interest for this research is a three-dimensional orthotropic elasto-plastic composite material model that requires a total of 12 experimental stress-strain curves, yield stresses, and Young’s Modulus and Poisson’s ratio in the material directions as input. Sometimes it is not possible to carry out reliable experimental tests needed to characterize the composite material. One solution is using virtual testing to fill the gaps in available experimental data. A Virtual Testing Software System (VTSS) has been developed to address the need for a less restrictive method to characterize a three-dimensional orthotropic composite material. The system takes in the material properties of the constituents and completes all 12 of the necessary characterization tests using finite element (FE) models. Verification and validation test cases demonstrate the capabilities of the VTSS. / Dissertation/Thesis / Masters Thesis Engineering 2015

Dans un contexte de réduction importante des coûts dans le domaine des lanceurs spatiaux, il devient primordial de contrôler l'ensemble des facteurs dimensionnants dès la conception. La diminution de la masse est compensée par une augmentation de la raideur et il en résulte une diminution de l'amortissement, qui est le paramètre qui conditionne les niveaux de la réponse dynamique. A l'heure actuelle, l'amortissement est pris en compte de manière globale et le plus souvent identifié sur la structure finale. L'objectif de ce travail est de proposer une démarche de prédiction de l'amortissement dans les lanceurs spatiaux afin de prendre celui-ci en compte dès la phase de conception. Cette démarche passe par la mise en place d'une base de données des coefficients d'amortissement en fonction du type de sollicitation, du niveau de chargement, de la géométrie... L'amortissement étant bien connu pour les matériaux qui composent le lanceur, l'enjeu est la détermination de l'amortissement dans les liaisons, où les dissipations peuvent être très importantes. Les démarches expérimentales étant coûteuses et complexes à mettre en place, le travail s'est tourné vers une approche numérique, basée sur un calcul éléments finis des liaisons. Ce type de simulations est actuellement hors de portée des codes de calculs industriels standards et a nécessité le développement d'un code de calcul parallèle spécifique, basé sur la méthode LATIN. La robustesse de l'outil numérique a été étudiée et les résultats ont été validés à partir de valeurs obtenues expérimentalement lors d'une étude précédente. Enfin, le calcul de différentes liaisons constitutives du lanceur a été abordé ainsi que la méthodologie pour intégrer ces résultats dans le processus de dimensionnement d'Ariane.

Multi-body system dynamics is one of the most important theoretical achievementsin mechanics. With the development of the theory, corresponding commercialsoftware packages have been developed and are used for modellingand simulation of complicated large systems, such as air planes and vehicles.This kind of virtual prototypes can be used for studies and assessments ofreal systems even before the real systems are built. As a result, the high costprototype building and prototype testing can be saved, so as the time can bereduced. This is just the demand of modern industry. This theory can beapplied on the vehicle-virtual road interaction study which has been used inthis thesis.This thesis suggests a target velocity prole for a heavy vehicle which driveson tough road. Having uneven and hilly road, actual driving conditions arechanged as the driver runs the vehicle. Drivers can perceive the road conditionwith their visual organ and sense of balance and then they control theirvehicles more safely by re ecting various conditions of this target velocityprole. Without this process, the driving-stabilization on slope and twistingroads would fall considerably, and the problem could be directly connected tooverturning. This thesis, moreover, will show how to acquire the road data,extract the velocity prole, and verify the performance of the suggested velocityprole through virtual road test.In vehicle-virtual road interaction simulation, multi body system (MBS) dynamicswith software Adams has been employed to model an articulatedhauler. The simulation has been validated by velocity prole test data andcompared to the former velocity prole. This method can be used for estimatingthe eects of dynamic forces on the frame so that the load design canbe assessed in vehicle design process.This project is in collaboration with Volvo Construction Equipment AB,Braas, Sweden.

Within the AutoDrive project, openPASS is used to develop a cognitive stochastic traffic flow simulation for urban intersections and highway scenarios, which are described in deliverable D1.14. The deliverable D2.16 includes the customizations of the framework openPASS that are required to provide a basis for the development and implementation of the driver behavior model and the evaluated safety function. The trial design for the evaluation of the safety functions is described. Furthermore, the design of the driver behavior study is introduced to parameterize and validate the underlying driver behavior model.

As part of the AutoDrive project, OpenPASS is used to develop a cognitive-stochastic traffic flow simulation for urban intersection scenarios described in deliverable D1.14. The deliverable D4.20 is about the design of the modules for the stochastic traffic simulation. This initially includes an examination of the existing traffic simulations described in chapter 2. Subsequently, the underlying tasks of the driver when crossing an intersection are explained. The main part contains the design of the cognitive structure of the road user (chapter 4.2) and the development of the cognitive behaviour modules (chapter 4.3).

As part of the AutoDrive project, the OpenPASS framework is used to develop a cognitive-stochastic traffic flow simulation for urban intersection scenarios described in deliverable D1.14. This framework was adapted and further developed. The deliverable D5.13 deals with the construction of the stochastic traffic simulation. At this point of the process, the theoretical design aspects of D4.20 are implemented. D5.13 explains the operating principles of the different modules. This includes the foundations, boundary conditions, and mathematical theory of the traffic simulation.

No description available.

No description available.

This paper examines the model-based design of thermal systems in mobile machines with a focus on heat exchanger design. An industry project is described in which the vapor compression cycle for the air-conditioning system was modeled using the software SimulationX. By modeling heat exchanger sections separately, multiple flow arrangements could be tested without the need for physical prototypes. The paper presents this work in the context of the full model-based design process including extensions for hardware in the loop (HiL) testing of control units and operator training using virtual machines.