Early Stages Of Vehicle Design Research Articles

Innovative Vehicle Design Processes Based on the Integrated Framework for Abstract Physics Modeling (IF4APM)

In industrial vehicle design processes, most companies have implemented model-based systems engineering (MBSE). As a consequence, design processes are nowadays not driven by documents, but by digital models of the vehicle to be developed and its components. These models exist on different levels of abstraction. The models on the requirements level are already well defined as well as the models of the defined product behavior and product properties. In recent years, the specification of models on the level of product functions was largely clarified, and elaborate frameworks already exist. However, this is not yet true for the level between functions and definite properties; this level can be referred to as "abstract physics". The enormous importance of this level, which, amongst others, can represent the physical effect chains which allow a vehicle component to function, is expressed by several researchers. Several research works aim at specifying models on this level, but, until now, no general consensus can be identified, and the existing model specifications are less appropriate for the early stages of vehicle design. This paper explains an Integrated Framework for Abstract Physics Modeling (IF4APM), which incorporates different perspectives of abstract physics and is suited for the early phases. The explanation is based on typical components of several kinds of vehicles. The main advantages of the proposed approach are the consistent interconnection of abstract product models, the clearness and understandability of the resulting matrices, and the aptitude to be used in the early phases of a vehicle design process.

Fire Path Analysis of Vehicle: To Prevent Vehicle Fire Incidents at Early Stages of Vehicle Design

Fire Path Analysis of Vehicle: To Prevent Vehicle Fire Incidents at Early Stages of Vehicle Design

Ultrasound Imaging Characterization of Soft Tissue Dynamics of the Seated Human Body.

To characterize the dynamics of internal soft organs and external anatomical structures, this paper presents a system that combines medical ultrasound imaging with an optical tracker and a vertical exciter that imparts whole-body vibrations on seated subjects. The spatial and temporal accuracy of the system was validated using a phantom with calibrated internal structures, resulting in 0.224 mm maximum root-mean-square (r.m.s.) position error and 13 ms maximum synchronization error between sensors. In addition to the dynamics of the head and sternum, stomach dynamics were characterized by extracting the centroid of the stomach from the ultrasound images. The system was used to characterize the subject-specific body dynamics as well as the intrasubject variabilities caused by excitation pattern (frequency up-sweep, down-sweep, and white noise, 1-10 Hz), excitation amplitude (1 and 2 m/s2 r.m.s.), seat compliance (rigid and soft), and stomach filling (empty and 500 mL water). Human subjects experiments (n = 3) yielded preliminary results for the frequency response of the head, sternum, and stomach. The method presented here provides the first detailed in vivo characterization of internal and external human body dynamics. Tissue dynamics characterized by the system can inform design of vehicle structures and adaptive control of seat and suspension systems, as well as validate finite element models for predicting passenger comfort in the early stages of vehicle design.

Modeling the high cross-country motion ability of a wheeled vehicle on deformable soil

Introduction. The improvement of the wheeled vehicles (WV) design intended for operation in areas with a poorly developed road network is an important task. The increase of vehicle operation efficiency allows significant reducing both the cost of freight traffic to remote areas of our country and development of new territories. The variety of soil surfaces on the territory of the Russian Federation makes it difficult to choose vehicle parameters at the early stages of vehicle design. Thanks to the high level of computer technology development, it is advisable to use the methods of WV motion simulation. Purpose of the study . The use of new approaches to the interaction calculation parameters of a wheel propeller with the ground, when the main features of the WV design are taken, allows to more accurately model the process of vehicle movement on a soil surface and take into consideration the mutual influence of various systems on the vehicle's cross-country ability when driving on deformable supporting surfaces. Methodology and research methods. The article presents a method for imitating the motion of a high passability WV on the deformable soil. The method is based on the principle of creating a mathematical model of WV in the environment of rigid body dynamics, extended by new models. The interaction modeling peculiarities of an elastic tire with deformable soil are to create an additional dynamic sphere. The algorithm of this sphere uses a model of the elastic tire interaction with deformable soil, developed by Professor Ya.S. Ageikin and supplemented by his students. Scientific novelty and results . The article considers an example of rectilinear motion of a WV on loam, the results of the study are presented. The approach makes it possible to comprehensively investigate the passability of the WV when moving on deformable support surfaces. The mathematical model takes into account the main WV systems and their characteristics: engine, transmission, power flow distribution mechanisms (differentials) and their condition, wheel propeller, massive inertial properties of WV links. Practical significance. The developed method makes it possible to analyze the passability of, both existing and newly developed WVs. It also allows you to study the mutual influence of WV systems on the ability to move on various soil surfaces. At that the loads on the load-bearing elements of the WVs are determined, the loading history for resource assessment included.

Prediction of HAVC Cool-Down Performance inside a Minibus Passenger Cabin Using CFD and Its Experimental Validation.

Now with more time spent by people while travelling and increasing mobility, providing passengers with a thermally comfortable experience are one of the important targets of any bus manufacturer. Conversely, comprehensive assessment through Climatic Wind Tunnel testing is costly and not possible during early stages of vehicle design. The aim of this work has been to develop a simplified simulation methodology to model the Minibus passenger cabin for cool down test. This study presents a methodology for predicting Heating, Ventilation and Air Conditioning (HVAC) cool-down performance inside Minibus cabin using Computational Fluid Dynamics (CFD) simulation to revise the HVAC duct design and parametric optimization in order to ensure thermal comfort of occupant. Heat Load is calculated analytically and has been considered in the CFD model and occupant heat load is considered as per ASHRAE standard. CFD simulation predicted the temperature and velocity distribution inside passenger cabin. Simulated cool-down results were found to be in good agreement with the experimental results. CFD cool-down prediction is useful in order to reduce time and costs related to climatic wind tunnel and road tests. Validated CFD model is used to study the effect of air flow on cool-down performance.

Life cycle energy optimisation: A proposed methodology for integrating environmental considerations early in the vehicle engineering design process

To enable the consideration of life cycle environmental impacts in the early stages of vehicle design, a methodology using the proxy of life cycle energy is proposed in this paper. The trade-offs in energy between vehicle production, operational performance and end-of-life are formulated as a mathematical problem, and simultaneously balanced with other transport-related functionalities, and may be optimised. The methodology is illustrated through an example design study, which is deliberately kept simple in order to emphasise the conceptual idea. The obtained optimisation results demonstrate that there is a unique driving-scenario-specific design solution, which meets functional requirements with a minimum life cycle energy cost. The results also suggest that a use-phase focussed design may result in a solution, which is sub-optimal from a life cycle point-of-view.

A contribution to research of the influence of degradation of vehicle vibration parameters on thermal load of shock absorbers

Summary: Dynamic simulation, based on modelling, has a significant role during to the process of vehicle development. It is especially important in the first stages of vehicle design, when relevant parameters are to be defined. In practice, it is commonly assumed that vehicle vibration parameters are invariable, what is basically not true. Many investigations have shown that vibration parameters degrade in service conditions, what consquently leads to the variation of dynamic characteristics of a vehicle. This paper attempts to indicate, on the basis of the preliminary results, a need to introduce these variations, caused by the thermal impact, in the early stages of vehicle design through the adequate vehicle modelling.