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Image Correlation technique has been proven to be a flexible and useful for deformation analysis. It’s a robust method for measuring full-field absolute displacement and strains. In this paper we describe a new Digital Image Correlation (DIC) system, where all components (hardware and software) are fully integrated in order to build a self-contained measurement system. Due to a modular structure for hardware components as well as for the software in combination with high speed cameras this can be used for investigations on transient events. The calibration of a DIC system is the most important action, which is needed to generate accurate results. Therefore we describe the procedure, which allows an easy to use, reliable and fast calibration as an integrated part of the system. Results of measurement performed on a vibrating membrane and a tensile test sample are show typical features of the system.

Planetary gearboxes are used to transmit power and motion between rotating shafts using high reduction ratio. Design optimization of such gears requires information about the stress level on contacting surfaces of meshing gears, as it may influence durability and efficiency of the gearbox. Stress distribution in gears and pinions was estimated using following methods: a) Image correlation – photogrammetry – technique b) Holographic interferometry – holometry – technique c) Finite element analysis of contact problems. Image correlation is the white light technology. For the image correlation methodology digital pictures of the measured object taken simultaneously by two cameras are automatically correlated in ARAMIS 3D system. By means of triangulation calculation of coordinates of all the points in the images can be performed. Accuracy of the method depends on the field of view so very limited view area was considered for measurements.

Applications using two-dimensional and three-dimensional computer vision for deformation and shape measurements are described. First, the use of 2D image correlation for estimation of properties in heterogeneous materials is demonstrated. Second, the use of 3D computer vision for shape and deformation measurements in large, flawed panels is presented. Finally, the use of 3D computer vision for deformation measurement in cracked, ductile materials undergoing complex loading conditions is shown.

The reliable function of the system piston - piston ring -liner depends strongly on the correct quantity of oil. A balance between the sufficient oil offer and minimum emission is to be found. For this system numerous computation programs exist however their results strongly depends from the boundary conditions. To assist in the understanding of this system it is to be used necessarily optical research methods. So that the lubricating film at the piston and at the piston rings can be examined, a cylinder of an engine had to be completely made of glass. The used glass must have the wetting characteristics of grey cast iron, so that the results are transferable. The used tracers to visualize the oil may not change the characteristics of the oil. Different photograph procedures were necessary, in order to identify the fundamental presence of oil and the bearing oil film. In this paper the test set-ups and results are described.

Current simulation tools for the investigation of the dynamic system response as well as for the component stresses on the basis of multi-body and finite-element techniques are integral part of today's powertrain development efforts. These tools are typical used for the analysis and optimization of shafts, clutches, chain/belt drives, bearings, levers, brackets, housings and many other components. An exception is made by gears which today are still frequently investigated by the help of semi-empirical methods based on DIN, ISO, AGMA and the specific knowledge base of well experienced developers. The main difficulty is that the gears are rolling off via large contact surfaces with complex nonlinear mechanical contact properties. Within the scope of research work FEV developed a new method for the analysis and optimization of gear drives based on comercial multi-body and finite-element software platforms.

An exact approach to linearize the equations of motion of multibody systems is presented. The method has general applicability and it is well suited to linearize the index-3 Differential Algebraic Equations (DAE) governing the state of a dynamical system. Moreover, the method was extended to linearize a dynamical system in terms of user-defined coordinates without the need to reformulate the governing equations; this feature is of particular interest in disciplines like rotordynamics where eigensolutions are requested in terms of coordinates defined in a rotating frame. Contrary to other linearization methods, the proposed approach implements a closed-form computation of the linearized equations of motion; all second order effects are taken into account and no numerical differentiation is required. The proposed method inflates the governing equations and then computes a set of sensitivities that provide the linearization of interest.

This paper presents a shape optimization method for the rigidity design of sheet metal structures under multiple loading conditions with the aim of weight reduction. In order to maintain the curvatures of the given initial shape, it is assumed that the design domain is varied in the in-plane direction. Using compliance as an index of the rigidity, a volume minimization problem subjected to multiple rigidity constraints is formulated as a non-parametric shape optimization problem. The shape gradient function and the optimality conditions are theoretically derived for this problem. The traction method is applied to determine the smooth in-plane domain variation that minimizes the objective functional. The calculated results of fundamental design examples and actual automotive chassis components will show the effectiveness and practical utility of the proposed method in solving shape optimization problems of sheet metal structures.

Blow moulding is one of the most important polymer processing method for producing plastic automotive parts. Yet, there are still several problems that affect the overall success of forming these parts. Among them, are thermally induced stresses, relevant shrinkage and part warpage caused by inappropriate solidification conditions. This work presents a finite element model that allows for predicting residual stresses and subsequent deformations that arise during the cooling stage of finished parts. It is expected that the virtual presence of the flash zone has an influence on the development of residual stresses in the numerical model. Deflashing is usually performed immediately after part removal from the mould, therefore, the numerical model is adapted to take this into account. Numerical results obtained with and without flash for a simple part, as well as a complex automotive part, are compared to determine accuracy and limitations of the model.

For efficient prediction of single and multiple impacts on bumper energy-absorber systems, it is necessary to have certain important aspects represented by the model that represents the material of construction. These aspects include true stress-strain behavior, strain rate effects, hydrostatic effects, multiple failure criteria and recovery of material during unloading. An existing material model in the explicit solver LS-DYNA covers these aspects, and this paper aims at exploring the sensitivity of this model to finite element parameters. This is done by simulating multiple impacts on two designs, and comparing with test data. Results indicate that FE model parameters, stiffness variation, and contact definitions play a vital role in obtaining a solution.

Fluid Structure Interface (FSI) analyses were fast in development during recent years with the constantly advancing progress of computer technology. MpCCI (Mesh based parallel Code Coupling Interface) is a typical product of FSI. MpCCI has been developed at the Fraunhofer-Institute SCAI in order to provide an application-independent interface for the coupling of different simulation codes. Although FSI includes both flow induced displacement and thermal flow induced thermal stress, latter has received less attention. In this paper, temperature results of a transient thermal fluid analysis in a T pipe are used as loads for a nonlinear plastic thermal stress analysis of the pipe. In the nonlinear plastic analysis, linear proximity is used for both plastic region and elastic region. That is to say, 2-line kinematicl hardening law is used to express the stress strain characteristic of the pipe. At the same time, different numbers of load are used and the results are compared.

Historically, worst case circuit analysis (WCCA) has been applied primarily in industries requiring very high reliability (e.g., telecommunications, defense and aerospace). Unfortunately, the techniques for WCCA have been relatively difficult to perform and involve time-consuming iterative and statistical processes [1, 2, 3]. High reliability is now required in automotive applications. This paper describes a patented [4], non-iterative, automated worst case circuit design and analysis (WCCDA) method that is practical for budget and time limited projects. Reliable circuit performance over extreme operating temperature ranges (e.g., from −65°C to 125°C) is achieved. Circuits are designed and analyzed in less than two minutes, and no special tools are required.

An experimental method was required to evaluate both the operability and the influence on safety of in-vehicle devices used while driving. We proposed to measure the number of errors, operation time, glance time, and variations in steering angle and yaw angle through objective tests, as well as eliciting subjective evaluations by participants. We conducted an experiment in which, using a driving simulator to evaluate a center-cluster panel switch and a new human-machine interface (HMI) with a head-up display (HUD) and steering wheel switch (SWS), the participant follows a lead vehicle on an expressway. Results indicate that the experimental method is effective for comprehensively evaluating in-vehicle devices and identifying where improvements are needed. The merits of the new HMI are also discussed.

It is an important problem to estimate the fatigue life of spot welds. There are a number of spot weld models in literature put forward to represent spot welds in finite element models. In this study, five popular spot weld models are compared with each other and experimental results. It is concluded that 9-point contact method is the best one among other models considered in this study based on strain measurements. In terms of fatigue tests, 9-point contact and umbrella models yield better-correlated results than the rigid and elastic beam models.

For reasons of convenience and safety, it is important to assess the drivers' workload while using in-vehicle devices. Recently, we proposed a new psychophysiological measure for assessing drivers' attention: eye-fixation-related-potential (EFRP). EFRP is a kind of event-related-brain potential (it were made of brain waves (EEG) and the electrooculographic (EOG)) measurable in normal driving. In the present study, we manipulated the cars' navigation system and measured the affect on drivers attention by measuring EFRPs. There were two tasks: a voice-activated task (the drivers manipulated the navigation system via voice) and a manual task (the drivers manipulated the navigation system by hand). The results showed that the amplitude of P100 component of EFRP during simulated and actual driving decreased greatly with the manual task when compared to the voice-activated task.

Electronic navigational systems allow drivers to receive travel directions while driving, rather than preplanning a route. This additional attentional load on drivers might prove to be hazardous -- particularly for older adults who have greater difficulties multitasking and switching their attention between different parts of the visual field. A driving simulator was used to evaluate the perception time to critical events in the presence and absence of a navigation system with young (n=18, age=18.8years SD= 0.7years) and older drivers (n=15, age=73.1years, SD=6.1years). The results of this study indicated that though older drivers were slower to react to critical events, and both groups were faster to react to pedestrian incursions than sudden light changes, messages from the travel system did not interfere significantly with perception reaction time in either group.

Two navigation systems, one a turn-by-turn and the other a moving-map, were compared using the same routes and waypoints in the area of Roanoke, VA. Challenges as a result of their varying algorithms used to determine route guidance were overcome in finding a common route between the two systems. The study was designed to be conducted without an in-vehicle experimenter. This approach was thought important to reduce potential experimental biases. The methodology described provides a low-cost, valid method to test way-finding using the actual system in its actual driving environment. The purpose of this paper is not to discuss the benefit of a moving-map system as compared to a turn-by-turn system, but to discuss the methodology of this way-finding study conducted without an in-vehicle experimenter. Suggested data to collect and/or analyze as well as lessons learned are also discussed.

In closed wall test sections the total correction to the measured drag usually consists of several parts: solid blockage corrections related to the displacement of the model, horizontal buoyancy corrections due to empty tunnel gradients and the wake blockage corrections, which are necessary to handle effects created by the displacement effect of the wake. The latter will be investigated in more detail in the paper. The wake blockage correction usually consists of two parts: a correction to the measured dynamic pressure (q-correction) and a gradient correction, the so-called wake induced drag increment. Both corrections are directly dependent on the source strength which is equivalent to the displacement effect of the wake. Therefore the displacement of the wake is analyzed in more detail.

This paper describes a novel prototype driver support system aimed at improving drivers' awareness of changing situations ahead as well as at reducing the frequency of approaching a preceding car closely. The control algorithm is based on the idea of a virtual repulsive force that increases as the host vehicle draws closer to a car ahead. The virtual repulsive force is utilized to determine the accelerator pedal reaction force and to control the effective driving and braking force. A build-up of accelerator pedal reaction force helps drivers recognize that the situation ahead is changing towards a more critical state so that they can appropriately release their accelerator pedal and be ready to operate the brake pedal. The driving and braking force control, which is used in parallel to the control of the accelerator pedal reaction force, is designed to actively reduce the frequency where the host vehicle driver closes in on a preceding car without driver's intention.

This paper characterizes the capability of a rear-end crash avoidance system based on data collected from a field operational test. The system performs forward crash warning and adaptive cruise control functions. The test consists of 66 subjects who drove 10 equipped vehicles on public roads over 157,000 km. System characterization addresses the ability of the forward-looking sensor suite to maintain in-path target tracking and discern between in-path and out-of-path targets; the efficacy of the alert logic in warning the driver to driving conflicts that may lead to rear-end crashes; and the visibility, audibility, and readability of information displayed by the driver-vehicle interface.

During the last decade, three major HMI-guidelines have been developed, each addressing the specific situation in Europe, the U.S. and in Japan. On the basis of a detailed comparison of the three approaches, the effect of these guidelines on the product development process and the products are described as well as their anticipated effect on traffic safety. Finally potentials for harmonization and needs for standardization and further research are described.