An aftertreatment system is the back-end component of an automotive exhaust system, used mainly to reduce pollutant emissions. This system is exposed to high thermal loads which can exceed temperatures of 900 oC , usually they operate at temperatures under 600 oC - 700 oC, depending of the engine application. The durability assessment of a system under thermomechanical loads can be challenging due to the complexity of the technical problem, which involves complex material behavior at high temperatures and results in high thermomechanical strains and stresses. This study presents a computational approach for the lifetime assessment of an exhaust aftertreatment system subjected to thermomechanical loading. The method is composed of a fluid flow analysis to compute the temperature fields which are mapped to a mechanical analysis combined with a nonlinear elastoviscoplastic material behavior. Lastly, the lifetime of the overall assembly is assessed through a fatigue analysis.
Magnet wire is composed of conducting core and thin layer of electrical insulation. Cupper (Cu) is typically used as conducting core, and various polymers such as polyamideimide, polyimide, and polyesterimide are used for electrical insulation. The role of magnet wire is involved in interchanging between electrical energy and mechanical energy for energy transformation application such as transformer, motor, generator, and many other equipment. Currently, electric vehicles (EV) industry is rapidly growing and consequential demands on related components are increasing as well. Compared to combustion engine, EV needs more electrical power with higher voltages or higher currents, which can increase probability of electrical discharge. The degradation of insulation layer can happen with the polymer bond breakage under the partial discharge electric stresses.
Alumina (Al2O3) thin film coatings are applied on Al alloys using Plasma Electrolytic Oxidation (PEO) method to reduce the wear and corrosion problems. Plasma Electrolytic Aluminating (PEA) is a technique that could generate Alumina coatings on cast iron, mild steel, and copper alloys. In this study, the aim is to explore the anti-wear and anti-corrosion behaviours of PEA Alumina coatings on gray cast iron. The dry sliding tribology test data was obtained from Pin-on-Disk (POD) tests against SAE 52100 steel and Tungsten Carbide (WC) counterfaces. Comparing to the PEO Alumina coatings, the PEA Alumina coating has a much lower Coefficient of Friction (COF) and less wear. The microstructure, chemical composition, and phase composition of this coating were investigated with Scanning Electron Microscope (SEM), Energy-Dispersive X-Ray Spectroscopy (EDX), and X-Ray Diffraction (XRD), respectively. There was FeO (or FeAl2O4) found on the PEA Alumina coating.
In order to meet the needs of modern warfare, the research on electromagnetic shielding technology of military vehicle-mounted shelters and improving the electromagnetic shielding performance of shelters will play an increasingly important role in the protection of advanced electronic equipment. At the same time, it is also the core of the development of military vehicle-mounted shelters. In this paper, by selecting and comparing different materials, using multi- layer composite materials to design the military vehicle-mounted shelter. The shelter body comprises a front wallboard, a rear wallboard, a left wallboard, a right wallboard, an upper wallboard and a lower wallboard.
Metal binderjetting is a high throughput additive manufacturing process that has the potential to meet the needs of automotive volume production. In many cases, this process requires a sintering post-process to meet final dimensions. Because the sintering stage is performed free standing (i.e. without the use of tooling) and can involve up to a 20% dimensional change from green part to the final part shape, part distortion can be a concern. In this study, the sintering stage of a bridge geometry was simulated under different parameter settings using a Finite Element Analysis. The sensitivity of the simulation to various process parameter inputs was examined. Parts were then produced in 316L using a bound metal deposition and sintering process and compared to prediction. The sintering simulation indicated good agreement with experiment for some dimensions but highlighted the need for additional analysis.
A low carbon, lean alloyed chemistry was selected for the development of high strength dual phase (DP) steels with enhanced global and local formability. Optimized best process conditions including clean steel practices, choice of suitable casting powder, hot rolling and continuous anneal set points resulted in excellent mechanical properties and formability characteristics of DP steels. The enhanced balance of strength and formability is attributed to the optimization of the microstructure through refinement, uniformity and balancing microconstituents mechanical response and guaranteeing outstanding internal cleanliness. In this contribution, production strategy and formability characterization of DP steels with tensile strengths of 780 MPa and above relevant to automotive body structure applications will be discussed.
Padded self-piercing riveting (P-SPR) is a newly developed multi-material joining technology to enable less ductile materials to be joined by self-piercing riveting (SPR) without cracking. A deformable and disposable pad was employed to reduce the stress distribution on the bottom surface by supporting the whole bottom sheet continuously during rivet setting process. To verify the P-SPR process, 2.0mm thick 6061-T6 wrought aluminum was joined with 3.2mm thick coated AM60B magnesium high pressure die casting (HPDC) by using 1.0mm thick dual-phase 600 (DP600) steel as the pad. Regular SPR processes with 2 different die geometries were studied as a comparison. Compared to the regular SPR processes, P-SPR demonstrated advantages on coating protection, crack mitigation and joint strength.
Most of the applications of magnesium in lightweighting of commercial cars and trucks are die castings rather than sheet metal, and automotive applications of magnesium sheet have typically been experimental or low-volume serial production. The overarching objective of project was to develop new low-cost magnesium alloys, and demonstrate warm-stamping of magnesium sheet inner and outer door panels from a 2013 MY Ford Fusion at a fully accounted integrated component cost increase over conventional steel stamped components of no more than $2.50/lb. saved. The project demonstrated the computational design of new Mg alloys from atomistic levels, cast new experimental alloy ingots and explored thermo-mechanical rolling processes to produce thin Mg sheet of desired texture. A new commercial Mg alloy sheet material was sourced and pretreated with protective coil coatings, and its properties fully characterized.
The compression fatigue behavior of sheet metal trimming die is studied. The trim dies were manufactured or reconditions through different fabrication processes and heat treatment conditions. An accelerated lab testing method is developed to evaluate die damage resistance under compressive cyclic load applied at the tool edge, analogous to sheet metal trimming die operation. The metal removal volume at the sheared edges were measured by image processing to quantify the degree of fatigue damage as a function of loading cycle number. The fatigue microstructural damage were examined with optical and scanning electron microscopies. The simulated die performances are compared among different die processing routes. A phenomenological trim die damage rate model in Paris law form was obtained and tuned with experimental data for tool life prediction.
The emergence of additive manufacturing (AM) technology has enabled the internal cooling channel layout for high pressure aluminium die casting (HPADC) tools to be designed and modified without topological constraint. Optimisation studies of a full industrial HPADC mould for extending the tool service life has received limited attention due to the high geometrical complexity and the various physics with multi time and length scales in addition to the manufacturability limitations. In this work a new computational efficient algorithm that employs the adjoint optimization method has been developed to optimize the coolant channels layout in a complete mould with various 3D printed inserts. The algorithms reduced significantly the computational time and resources by decoupling the fluid flow in the coolant channels from the tool and simulating them separately.
Vehicle windshields typically include a black decorative pattern around their periphery and other regions. Examination of field failed parts has shown that windshields often break from impacts in these decoration zones; often with the fracture initiating from the decoration material itself. In this work, the effect of different glazing decoration materials on glass strength and laminate impact resistance was evaluated. The decoration materials investigated included traditional inorganic enamel frit, an organic ink, and a new enamel frit that is compatible with glass chemical strengthening. Ring-on-Ring strength tests were conducted and showed that inorganic enamel frit reduces strength of glass by over 50% compared to undecorated glass, while organic inks do not adversely affect strength. Tests of a newly developed decoration frit material, compatible for chemical strengthening processes, showed strength levels that were on par with undecorated, unstrengthened glass.
Abstract— Axle transmits power from the gearbox to the wheels. There are primarily two reasons for reducing the Axles diameter in the case of a bipod CV joint namely, to avoid overdesigning and less articulation angle. As the ATV goes in a bump/ droop, a driveshaft with a larger diameter would hit the walls of the CV joint which creates hindrance in its articulation. And, if the driveshaft is overdesigned, it will add unnecessary weight and effort to the power train which would decrease the overall performance of the vehicle. We have reduced the diameter of the axle using real-time testing data by taking the help of various machines to validate that component not failing under the given load conditions; research work is divided into 3 phases of Data collection, Axle design, and validation. Total 3 test rigs were set up for Data collection and validation, combined with axial design, material selection, heat treatment, and CAE validation.
With the degradation of lithium-ion batteries, the battery safety performance changes, which further influences the safe working window. In this paper, pouch ternary lithium-ion battery with a rated capacity of 4.2 Ah is used as the research object to investigate the impact of high-temperature calendar and cyclic aging on the tolerance performance. The overcharge-to-thermal-runaway test is performed on the fresh cell and aged cell (90% SOH). the inflection point of voltage for aged cell appears earlier than that of fresh cell, while the voltage corresponding to the inflection point is the same for them, which means that the voltage at which lithium plating occurs is the same. However, the voltage plateau and the crest voltage before thermal runaway of aged cell is significantly higher than that of fresh cell. Besides, for the thermal runaway triggering, ohmic heat, reversible heat, and side reaction heat all make contribution, among them, the side reaction heat plays a dominant role.
For cold gas Inflator, high refinement of ultimate pressure load forecast of inflator housing is one key of Inflator development. For inflator housing hydro-burst test ultimate load FEA calculation, arc-length method is utilized for obtaining high precision results. At beginning, the material parameters of inflator housing for simulation is correlated. The FEA material model adopts the stress-strain data from uniaxial tensile experiments. Considering the geometrical nonlinearity resulting from large deformation as well as material nonlinearity from plastic hardening, the whole tensile process from tensile deformation to failure of the specimen is stimulated by utilizing the arc-length method. Numerical results show that the arc-length method is appropriate to predict the entire deformation process, and the obtained key deformation stages, the distribution and inclined angle of the localized necking occurs also agrees with that of theoretical analysis.
Electric vehicle performance needs challenge connector designers and powertrain engineers with new paradigms for performance under more rigorous operational conditions. Traditional connector design protocols direct the engineer to silver plating for the contact interface, but these coatings have a maximum interface temperature of 170 C (ambient temperature plus T-rise). To avoid thermal runaway, engineers have to derate the ampacity of powertrain connections, which reduces available energy delivery as the temperature increases. This is especially true during transient power events like regenerative braking and acceleration. The soft nature of silver coatings make them well suited for power delivery and low contact resistance, but requires an engineering trade-off for wear durability. This is especially problematic for charging connectors which require tens of thousands of mating cycles before failure.
The conventional Wheel assembly is optimized using Stub and Hub integration by researching and evaluating new assembly designs, Material selection using Charpy impact test on different materials (EN24, 20MNR5, EN36) with different hardening processes (through hardening, Carburizing) are evaluated for the best combination of material and type of hardening which absorbs highest impact energy, which further evaluated for different types of brittle and ductile failure on those specimens, Component designing is performed considering various boundary condition evaluated for BAJA SAE ATV which includes Bump force due to hill fall down, Tension/Compression generation in case of improper landing on wheels, Torsion transfer through axle and Lateral forces due to centrifugal forces were used for design calculation and then FEA is used for Design validation. Finite model is generated in Hypermesh using various Meshing techniques considering rotating symmetry for achieving good quality criteria.
Strength, creep and fatigue of the chassis components are greatly influenced by the material used and its manufacturing process. Alloy wheel is one of the critical chassis components manufactured using the casting process. Secondary Dendrite Arm Spacing (SDAS) is one of the important microstructural parameters generated during the solidification stage of the casting process and it has a significant role in altering the mechanical properties and the behavior of the component. Variation in solidification time and alloy composition will have a major impact in SDAS. Combined effect of SDAS with microstructural variations and the strength behavior has not been studied in earlier literature for an alloy wheel. The scope of this study is to perform casting simulation for an alloy wheel, predict the SDAS and capture the variation of mechanical properties (yield strength, ultimate tensile strength & elongation).
Industrial hard chrome plating is a rather complex, lengthy and labour-intensive process: typically, the low cathodic current efficiency of Cr plating baths results in limited deposition rates, taking an hour to deposit a thickness of 25 mm on any size of the part. In the majority of cases, the hard Cr plating process requires the use of tooling structures, making the process strongly operator-dependent and therefore, highly prone to errors. According to the Fokker Landing Gear BV team, operator-independence as well as process simplification are expected to be achieved by developing a purpose-built tooling concept. An intelligent support of employees in their increasingly complex work is also sought and thus far addressed by implementation of modern smart technologies. One of them is computer modeling and simulation, which enables to mirror the physical world in a virtual model.