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Amid all nondestructive testing (NDT) methods Ultrasound is considered the most practically feasible modality for quality assessment and detection of defects in automobile industry. Pattern recognition of the ultrasonic signals gives us important information about the interrogated object. This information includes size, geometric shape and location of the defect zone. However, this would not be straightforward to extract this information from the backscattered echoes due to the overlapping signals and also the presence of noise. Here in this study, we suggest a new method for classification of different defects in inspection of adhesively bonded joint. At the first step of this method, the problem of parameter estimation of the reflected echoes is defined in a Maximum Likelihood Estimation (MLE) framework. Then a space alternating generalized Expectation Maximization (SAGE) algorithm is implemented to solve the MLE problem.

Material formability is a very important aspect in the automotive stamping, which must be tested for the success of manufacturing. One of the most important sheet metal formability parameters for the stamping is the edge tear-ability. In this paper, a novel test method has been present to test the aluminum sheet edge tear-ability with 3D digital image correlation (DIC) system. The newly developed test specimen and fixture design are also presented. In order to capture the edge deformation and strain, sample's edge surface has been sprayed with artificial speckle. A standard MTS tensile machine was used to record the tearing load and displacement. Through the data processing and evaluation of sequence image, testing results are found valid and reliable. The results show that the 3D DIC system with double CCD can effectively carry out sheet edge tear deformation. The edge tearing test method is found to be a simple, reliable, high precision, and able to provide useful results.

This paper introduces an industrial application of digital image correlation technique on the measurement of aluminum edge stretching limit. In this study, notch-shape aluminum coupons with three different pre-strain conditions are tested. The edge stretching is proceeded by standard MTS machine. A dual-camera 3D Digital Image Correlation (DIC) system is used for the full field measurement of strain distribution in the thickness direction. Selected air brush is utilized to form a random distributed speckle pattern on the edge of sheet metal. A pair of special optical lens systems are used to observe the small measurement edge area. From the test results, it demonstrate that refer to the notched coupon thickness, pre-tension does not affect the fracture limit; refer to the virgin sheet thickness, the average edge stretch thinning limits show a consistent increasing trend as the pre-stretch strain increased.

There has been a requirement for automotive bearings materials to be free of the toxic material lead, in accordance with ELV regulations and from the perspective of environmental problems. Currently, bismuth is used as a replacement for lead in copper alloy based main journal bearings and connecting rod bearings for automotive engines. In recent years, there has been changing to lead-free materials for truck engine bearings. Compared with automotive engines, lots of contaminations in the oil and local contact between the shaft and bearings can occur in truck engines. The ability to tolerate contamination and local contact is therefore required for truck engine bearings. In this development, we find that the addition of 8 mass% bismuth and 1.5 mass% molybdenum carbide particles into copper-tin alloy is effective for improving the ability which allow the contamination and local contacts. The development of above mentioned lead-free copper alloy bearing material is described here.

In modern car engines, the oscillating masses, the inertia forces of the moving engine parts has to be kept as low as possible. Small oscillating masses are not only the basis for the engine smoothness; they also have a great influence on the reliability and life of the components. The smaller oscillating mass in the crank mechanism minimizes, the weaker the vibrations and reduces friction and wear of the parts. The contribution of the piston pin to the oscillating mass can be between ten and thirty percent. Mass reduction of the piston pin has a corresponding large effect. In the newly developed MAHLE composite piston pin, an aluminum core is pressed in a steel sleeve. This enables a weight reduction in the piston pin up to twenty percent for gasoline engines and up to thirty percent for diesel passenger car engines. As the production of piston pins should be kept simple and economical, the new composite piston pin utilizes a forming process for its manufacturing.

In the new ThyssenKrupp InCar®plus project, numerous solutions were developed for vehicle components and systems that contribute to increased efficiency through the use of new materials and advanced manufacturing technologies. These solutions are superior to current production applications in terms of weight, cost, performance and sustainability, while also meeting the demand for cost-effective weight reduction. This paper features structural components solutions focusing on Bumpers, and A- and B-pillars which overall attained between 8% to 19% weight reduction compared to their significant reference parts by incorporating flexible design concepts, progressive new materials, virtual analyses, and innovative manufacturing processes that have been tested and validated along the entire value chain. The prototypes developed were subjected to stringent safety assessments.

The fatigue strength and failure behavior of A5754-O adhesively bonded single lap joints by a hot-curing epoxy adhesive were investigated in this paper. The single lap joints tested include balanced substrate joints (meaning same thickness) and unbalanced substrate joints, involving combinations of different substrate thicknesses. Cyclic fatigue test results show that the fatigue strength of bonded joints increase with the increasing substrate thickness. SEM and Energy Dispersive X-ray (EDX) were employed to investigate the failure mode of the joints. Two fatigue failure modes, substrate failure and failure within the adhesive were found in the testing. The failure mode of the joint changes from cohesive failure to substrate failure as the axial load is decreased, which reveals a fatigue resistance competition between the adhesive layer and the aluminum substrate.

This paper reviews the topic of Thermo-Mechanical Fatigue (TMF) as applied to automotive components such as cylinder heads, pistons, manifolds, turbochargers and exhaust components. The paper starts by looking at the physical influence of temperature on the microscopic failure of materials, in particular concentrating on the mechanisms of creep, fatigue, oxidation and their interactions. Finite Element Analysis (FEA) techniques suitable for high-temperature environments are discussed briefly, in particular the applications of elastic, elastic-plastic or elastic-viscoplastic analyses. Finally, methods for high-temperature fatigue and creep-fatigue based on the Chaboche approach are reviewed. The paper concludes with a review of laboratory tests on several materials at elevated temperatures under combined creep and fatigue conditions. Two case studies are then presented on a turbocharger housing and an exhaust-gas recirculation valve housing.

In this paper, both standard and constrained thermomechanical fatigue (TMF) tests were conducted on a high silicon ductile cast iron (DCI). The standard TMF tests were conducted with independent control of mechanical strain, out-of-phase (OP) and in-phase (IP) strain, and temperature in the range from 300 to 800°C. The constrained TMF tests were conducted with various constraint ratios of 100%, 70%, 60% and 50% at the temperature ranges of 160 to 600°C and 160 to 700°C. Based on a material model as calibrated with low-cycle fatigue (LCF) data of DCI, finite element analyses (FEA) of the above TMF tests were carried out with Abaqus. A damage mechanism-based lifetime model was integrated into a C++ API code to post-process the Abaqus output results. Simulation predictions show good agreement with experiments for stress-strain responses and lifetime under different TMF conditions.

The vehicle dimension parameters of the domestic passenger car in current Chinese market were analyzed. Combined with the human body golden ratio, a probability and statistics method was used to propose an intrinsic link between vehicle dimension and platform dimension, an intrinsic link between the dimensions of a vehicle. The proportion of coordination in different styles of models was analyzed also. A reference method was provided for the subsequent development models to define the dimension of the vehicle.

Carmakers have tried to lower the vehicle weight for raising fuel efficiency. This trend involves a trade-off with the vehicle stiffness. In automobile interior parts, the thickness has needed to be decreased for the weight reduction but this makes the stiffness worse. A new approach for improving the stiffness due to the weight reduction is required and various optimization methods at early development stage have been introduced currently. However, it is difficult to apply optimization for the interior parts since many interior parts' structures generally depend on the design. But as studying the structure in detail, we discovered some factors that affect the performance without depending on design. The door trim is selected for optimization item because it has many characteristics of automobile interior parts. In our case study, the factors that improve the performance of door trim without changing design are considered as fastener position and flange rib layout.

Performance data offers a powerful tool for system condition assessment and health monitoring. In most applications, a host of various types of sensors is employed and data on key parameters (describing the system performance) is compiled for further analysis and evaluation. In ensuring the adequacy of the data acquisition process, two important questions arise: (1) is the complied data robust and reasonable in representing the system parameters; and (2) is the duration of data acquisition adequate to capture a favorable percentage (say for example 90%) of the critical values of a given system parameter? The issue related to the robustness and reasonableness of data can be addressed through known values for key parameters of the system. This is the information that is not often available. And as such, methods based on trends in a given system parameter, expected norms, the parameter's relation with other known parameters, and simulations can be used to assure the quality of the data.

Material energy and cost minimization has been the need of the hour off late. The work aims at designing a micro gripping device which has suitable application in bio medical industry; specifically surgical operation of comminuted fracture using CAE software. Being a combination of an inverter and a clip, the ability of the compliant mechanism to be used as a gripper as well as positioner constitutes its rare versatility. The compliant mechanisms are single-piece structures, having no backlash as in case of rigid-body, jointed mechanisms and comparatively cheaper to manufacture. Designed in MATLAB R2008a using the concept of topological optimization, modeled in AutoCAD Mechanical 2011 and analyzed in ANSYS Workbench 13.0; the mechanism is initially designed with a geometrical advantage of 2. The MATLAB code which is an improvement of the 99 line code written by O.

Nonlinear ultrasonics is a powerful method for detecting microscopic damage and stress in materials. The method is based on introducing a perturbation signal at high frequency, and monitoring higher order harmonics for microscopic damage or quantifying the frequency shift for measuring stress. As the influence of microscopic damage and stress to the ultrasonic signal is weak, a highly precise measurement is needed. In this paper, errors in the measurement equipment, measurement methodology, and couplant type are experimentally quantified. Random errors and unknown systematic errors inherent to the method and its tools are defined. The measurement uncertainty in nonlinear ultrasonics is quantified. Based on the limitation of the measurement accuracy, minimum detectable stress level is defined.

This study explores the process changes and challenges encountered during the transition from physical to virtual automotive maintenance and service operations. The confirmation process was reworked significantly, while the final evaluation and reporting process was able to be maintained. Problems were encountered with the organization of the digital part data, the increase in workload of virtual simulations over physical checks, and the limitations of current simulation and virtual reality (VR) technologies. Ideas for future enhancements of product lifecycle management (PLM) and simulation systems are explored.

Plenty of dust particles which are generated when a sweeping vehicle is dumping harm to workers' health. In the study, the designed vacuum dust control system could effectively capture easily raised dust particles in the air in the premise of not impacting the dumping process so as to improve the unloading work environment. Firstly, longitudinal motion trajectory model of dust particles in the dumping process is established. Based on the side collision probability model of dust particles, lateral velocity distribution of dust particles is obtained. What's more, the scope of lateral dust particles is determined. Taking into account coupling of the dust control system and the working state of the vehicle, the suction mouth is arranged at the edge on the outside of hatch cover. Centrifugal horizontal dust removal system designed in the research is fixed in the middle of the filter cover part and discharging hatch cover area.

For the thin ice on the road in winter, the traditional road deicing vehicle relies on mechanical and chemical methods for melting ice, which is inclined to damage the pavement and has insidious influence on environment. The thermal deicing vehicle has been adopted in recent years. Although the deicing method is available, the deicing efficiency is unacceptable while the energy consumption is huge. The study adopts the new idea of “bottom-to-top” for melting the intersection area between the road surface and the bottom ice layer by the microwave heating firstly and then cleaning them out using high pres. vapor cutting so as to save the cost of energy and enhance the traffic safety. First of all, the mathematical model of the melting process of the intersection of the pavement and the ice layer was established according to the microwave heating characteristics.

This study examined various warranty data analysis methods to identify and study the one most suitable for Hyundai Motor warranty data. The drawbacks of the conventional life table method were overcome to develop an analysis method optimized for vehicle characteristics. The proposed method was examined for its suitability to various applications, such as providing the information necessary for determining the service life of parts, verifying the effects of design changes, and designing warranty and maintenance policies. The analysis data used in this study were derived from the 10-year powertrain parts warranty data of vehicles sold in the USA, South Korea, and China.

This paper proposes a multi-level decoupled method for optimizing the structural design of a wind turbine blade. The proposed method reduces the design space by employing a two-level optimization process. At the high-level, the structural properties of each section are approximated by an exponential function of the distance of that section from the blade root. High-level design variables are the coefficients of this approximating function. Target values for the structural properties of the blade are determined at that level. At the low-level, sections are divided into small decoupled groups. For each section, the low-level optimizer finds the thickness of laminate layers with a minimum mass, whose structural properties meet the targets determined by the high-level optimizer. In the proposed method, each low-level optimizer only considers a small number of design variables for a particular section, while traditional, single-level methods consider all design variables simultaneously.

As part of the design and validation of engine-mounted components, it is essential to define the vibratory mechanical environment in which these components will operate. This is required in order to optimize the reliability of such components subjected to loading from both the engine and road profile, while minimizing development costs and time scales. This paper presents a methodology that superimposes a swept sine on a power spectral density of acceleration in order to evaluate the mechanical durability of engine mounted or gear box mounted components. The first step in the process is to obtain the wave form of the dominant engine orders by extracting the deterministic signals from the random process using an order tracking method in the time domain. The second step is to assess the fatigue damage and extreme response spectra of a Swept-Sine-On-Random profile.