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Sustainable development is the ultimate focus for all the upcoming inventions and innovations in the modern world. Automotive manufacturers contribute their research in terms of producing eco-friendly vehicles since it is proven that internal combustion engine–powered vehicles directly affect the air quality with their polluting exhaust gas. The rapid emergence of zero tailpipe emission vehicles such as electric and fuel cell electric vehicles (FCEVs) obtained the attention of major automotive giants worldwide. owing to their green mobility, battery-operated electric vehicles have already hit the road despite the challenges of recharging time, availability of recharging stations, range-to-weight ratio, and battery life and its recycling process. Drastic upscaling research and development of hydrogen FCEVs paves the way to reach the goal of sustainable transportation with its air cleaning effect, long range, zero tailpipe emission, and quick refueling time. FCEVs run with the help of hydrogen and atmospheric oxygen leaving only pure water and warm air as an exhaust. The efficiency of a proton exchange membrane fuel cell (PEMFC) in FCEVs depends on various internal and external parameters. Research and development in terms of internal parameters with respect to the internal components of a fuel cell stack includes proper fuel and airflow channel design, efficient design of thin gas diffusion layer (GDL), and self-humidifying membrane structure design. On the other hand, the external parameters such as maintaining temperature, pressure and humidity of inlet hydrogen and air and its flow rate, and proper hydrogen recirculating system. In this article, considering the practical limitations of our fuel cell stack, we have considered only external parameters of oxygen concentration and temperature of the fuel cell stack for our experimentation. We did the experiment with oxygen cylinders and concluded that fuel cell stack efficiency increases with the increase in oxygen concentration from 21% to 50%. Also, we concluded that by maintaining the optimum temperature of the fuel cell stack with a variable flow coolant pump, maximum efficiency is retained in the temperature range of 40–55°C.

A competent numerical prediction on automotive restraint systems relies on accurate inflator characteristics as input data, which are specified to gas species composition, mass, and energy flow rate. Due to the highly transient processes under extreme temperature conditions of inflator deployment, the determination of inflator characteristics is very challenging. Current conventional methods utilizing tank pressure (Pt method) and/or chamber pressure (Pc-thrust method) measurements obtain numerous assumptions, for which their compatibility with the applied inflator type is often not considered.In this work, conventional Pt and Pc-thrust methods are detailed, assessed, and discussed. One stored gas and two pyrotechnic inflators are taken as scenarios, for which the interior ballistic models are created based on their design components and functions. The created inflator features are compared between the three methods. Further, validations are carried out in computational fluid dynamics (CFD) simulation on the tank test and finite element method (FEM) simulation on the Force INdicating Assessment Tool (FINAL) ton test.Results of the tank test and FINAL ton validation show different evaluations of the input data, which refers to a fundamental bias in interpreting and utilizing the inflator characteristics. The mismatch behavior between the two test environments reveals the inadequacy of using the information of the tank test as a single data source for airbag-relevant simulations. By assessing the applied assumptions in the conventional methodologies, it has turned out that the conventional methods are only appropriate for pyrotechnic-type inflators. Thus, the numerical ballistic approach is advised for stored gas–type inflators instead of conventional methods. Also, cross-validation is recommended for pyrotechnic inflators to adjust the gas amount and temperature level before the complex simulation takes place. These insights contribute not only to a better understanding of the inflator gas thermodynamics but also provide a general guideline for simulation engineers in acquiring more reliable solution in the restraint system development framework.

Casting is unique manufacturing processes for variety of reasons. Perhaps the most important reason is, it can produce complex components in any metal and weight ranging from grams to several tons. It is age old technology used to produce complex shapes and for mass production. The defects produced specifically inside the component, during casting process are difficult to identify. These defects in turn become cause of component failure in operating condition. FEA tools gives better understanding of process and can predict any defect produced in the casting process. It also helps to optimize entire process. Thus, use of software are becoming necessity in the industry to avoid rejections / last minute surprise.This paper describes use of simulation to predict casting defects accurately in existing casting component. This provides in depth understanding of existing casting process. With understanding of existing process defects, suitable modifications in the casting design and process were carried out to eliminate persisting casting defect. Production trials were conducted with suggested modifications in the pattern and the process. With suggested modifications, casting defect were eliminated. The modified design also reduced the casting input material weight by ~3% thus improves casting yield.

An automotive door latch that functions manually or electronically is a vital component of a door closure system. It primarily aims to provide security of the occupants by securing the door system by ensuring timely locking and unlocking of the doors. A wide range of factors like safety, ergonomics, and security influence the development of these latches to eliminate safety. With the growing trend and advancements, automotive electronics is becoming more complex and prevalent. Hence, any exposure of electrical/electronic components to water make them susceptible to short circuits, corrosion etc., thereby may make it the functionality of systems and increasing the chances of failure in these devices. Intrusion of water possible into the latch system can be disastrous depending on the climatic conditions. Stringent safety criteria have given rise to unconventional test methods that are time-consuming and hence necessitate virtual validation techniques. Virtual validation becomes a viable option and with proper correlation work it helps to address these types of problems at low cost and in early stages of product development The latch is subjected to an impact by a jet of water, modelled using Smoothened Particle Hydrodynamics (SPH) technique. SPH is a mesh-free method used to simulate fluid flow and has found its application in many engineering problems & fluid structure interaction (FSI) models. Since it can handle problems involving free surfaces, deformable boundaries, moving interfaces, extremely large deformation, and crack propagation, this was found to be an ideal technique for simulation. Water is made to impinge on the latch assembly and the/those water accumulated regions observed in the simulation were compared with the test results which are found to have good correlation. A design modification was suggested to prevent/minimize water ingression into the system which was further analyzed and proved to be efficient based on the FSI methodology.

The Indian market for battery-powered electric vehicles (xEV) is growing exponentially in the coming years, fueled by tumbling lithium-ion battery prices and favorable government policies. Lithium-ion battery is leading in clean mobility ecosystem for electric vehicles. LiBs efficient and safe performance for tropical climatic conditions is one of the primary requirements for xEV to succeed in India.The performance of LiBs, however, is impacted due to ambient temperature as well as the heat generated within cell due to the load cycle electrochemical reaction. The acceptable operating temperature region for LiBs normally is between 20 °C to 45 °C and anything outside of this region will lead to degradation of performance and irreversible damages. Therefore, understanding the thermal behavior is very crucial for an efficient battery thermal management.In this study the authors have focused on battery module thermal management by incorporating the thermal interface material (TIM) considering the target application of 2W & 3W EVs. A 3X3 battery module of 3s3p configuration were made with 21700 cylindrical form factor cells. The role of thermally conductive & electrically insulating silicone encapsulant for the thermal benefit and better thermal management was studied whose conductivity ranges from 0.48 W/mK to 2.7 W/mK. The experiments were carried out in two ambient temperature i.e. 25 °C & 45 °C. The discharging of the module was carried out at 1C. To analyze the thermal profile of the cells in the module, temperature measurements were acquired at eight locations with thermistors. It was observed that there is significant drop of Maximum temperature (Tmax) of greater than 10°C with TIM and the temperature uniformity (ΔT) is observed to be within 3 °C along with TIM. All the experiment was first carried out through virtual simulation. Equivalent circuit model of the cell was modelled from HPPC test and electro thermal virtual simulation of the experiments were carried out at cell and module level. Good correlation is observed and used for optimization of the BTMS design. Based on the output, authors conclude that the silicone-based TIM have greater role to play for the efficient battery thermal management in the battery pack.

Tyre rubber materials are viscoelastic in nature and generates heat during its operation due to hysteresis loss. Rubber being a poor thermal conductor, heat dissipation is a concern from product durability point of view. Further, during tyre manufacturing, curing is an essential process where heat conduction of rubber materials plays an important role to achieve desirable cure state. Therefore, thermal properties of rubber compounds are important inputs for tyre designing and manufacturing process. With this background, the present work focuses on characterising thermal properties (thermal conductivity, specific heat, thermal diffusivity, etc.) of rubber compounds using a Hot Disc Thermal Conductivity (TPS-2200, Sweden). In this work, new generation fillers, such as carbon nano tube were used in the rubber compounds to improve thermal conduction and thermal properties are compared with conventional carbon black based rubber compound. These new generation fillers are anisotropic in nature and have a colossal difference in the axial (in-plane) and radial (through-plane) heat flow. For these heterogeneous materials, anisotropic methods are more decisive compared to the isotropic one to obtain their actual thermal conductivity behaviour. Hence, a comprehensive investigation of heat profiles with varying morphology and texture has been elucidated in this work for detailed understanding of tyre curing with better prediction of product performance.

The oil is picked up from the oil sump and transferred to the pump housing via a suction tube at the desired rate. A strainer is fitted to the end of the suction tube to filter out any dust or debris that may be present. Steel tubes and wire mesh strainers are used to make the current suction tube. Suction tube design shouldn't have an excessively long inlet suction that would make the suction tube's pressure insufficient to suck the oil from sump. Additionally, the pump's suction side air leak or low temperature-induced low oil viscosity prevents the pump from priming. This paper will examine suction tube design analysis and compared the development of steel and polymer suction tube concepts. The lightweight polymer suction tube with respect to fluid dynamics aspects is compared with conventional wire mesh. Extreme temperature analysis of polymer suction tubes will be compared to baseline steel tubes for suction flow, the impact of mesh area, pressure drop, and temperature parameters, and findings will be presented. The flow performance of polymer suction tubes was found to be substantially above that of steel wire mesh suction tubes. Due to the decreased opening area of an all-polymer suction tube, the average pressure drop is larger, and pressure decreases in the suction tube have an impact on the pump's filling speed. Compared to steel suction tubes, polymer suction tubes are lighter and cheaper, easier to manufacture, need fewer parts, and have higher reliability.

Over the last decade, Climate change due to fossil fuel burning has taken centre stage in all discussions. Automotive sector has come under some flak for being one of the contributors to this Climate Change. Active steps have been taken by Vehicle Manufacturers and their Suppliers to address this issue. This sector has been facing below challenges to reduce pollutant in the air byA. Reducing Emissions, B. Increasing Energy Efficiency C. Use of Renewable Energy.One of the many alternatives by the Automotive Industry was to have a phased introduction to Electric Vehicles (EV), Hybrids, Fuel cells and other variants. As various emission norms and safety requirements takes Centre stage, it invariably, increases the weight of the vehicle. Now a days, Vehicles are having challenges to make it lightweight to achieve Range for an EV and improve fuel efficiency without sacrificing safety. It has also been observed that the weight of a vehicles is more due to the Structural Members made out of metal to meet all the Safety Norms.Innovative plastics and fiber reinforced composite materials offer a means to lightweight vehicle structures. Injection Moulding Composites (IMC) is one of the Technology to achieve this Light weighting target. IMC Technology is the combination of the Injection Moulded Process and Reinforcement Material to achieve the desired result. IMC is a suitable Technology for conversion of Metal to Plastics for Structural Parts, which gives the required strength and reduces weight of the parts.The IMC has a significant advantage over a traditional injection molding machine. With the IMC, the processor can compound his own material himself, i. e. introduce fibers, fillers or master batches, into the process directly during processing. Since the material purchasing represents the largest cost block in the injection molding of a part, the use of an IMC increases cost efficiency. Compared with premixed compounds, the purchasing of individual components is much more cost effective.

Corrosion in automotive industry is broadly categorized into cosmetic & perforation corrosion. Cosmetic corrosion comprises of superficial red rust which is deleterious to the overall aesthetic appeal of the vehicle but can be rectified. Perforation corrosion involves complete erosion of the panel, compromising structural integrity of the respective part. Perforation corrosion demands part replacement. In order to tackle this menace, automotive OEMs have formulated varied corrosion strategies in terms of selection of appropriate substrate, part design & surface protection scheme.Validation of various corrosion strategies become pivotal during the development phase of various parts and assemblies. Traditionally, Salt Spray Test (SST) has been used to determine corrosion life of materials/parts/assemblies. This test however does not simulate real-world conditions. Another test method, Cyclic Corrosion Test (CCT) with dynamic state conditions, wherein the relative corrosion rates, corrosion structure and morphology are more similar to those seen outdoors. However, there exist numerous CCT cycles having varied frequencies and intensities of salt fogging, wetting, ambient & drying cycles. Moreover, OEMs have formulated various-vehicle level Proving Ground tests wherein entire vehicle assembly is subjected to an accelerated corrosive condition.In the present Indian automotive industry, there does not exist a correlation between the predominantly used corrosion test cycles. In this study we have undertaken exhaustive evaluation of cosmetic corrosion performance in SST & CCT-two different Test Cycles. The cosmetic corrosion performance has been characterized based on observed creep-back analysis, after 1400 hours of testing. A comparative analysis has been undertaken of the cosmetic corrosion performance observed in various test cycles with respect to Proving Ground tests.

The design and development of a hydrogen powered spark-ignition engine, aimed for installation on a vehicle for on-road application. The experiment was conducted at WOT (Wide Open Throttle) condition at a speed of 4000 rpm with an excess air-fuel ratio of 1.3, 1.5, 2.2, 2.5, 3, 3.75, and 4.0. The ignition timing was optimized for maximum torque at each value of the excess air ratio. The various parameters analyzed such as in-cylinder pressure, Pressure and Volume, Logarithm of Pressure and Volume, Mass fraction burned, Cummulative heat release, Net heat release, Rate of pressure rise, and Mean gas temperature. The results show that there is a profound effect of excess air-fuel ratio on the engine’s mean effective pressure, output power, Brake thermal efficiency, Volumetric efficiency, Brake specific fuel consumption, and NOx emissions. The peak cylinder pressure decreases with an increase in excess air-fuel ratio and NOx emissions are reduced due to reduced mean gas temperature. Also, fuel energy is analyzed to review fuel energy converted to net power, heat lost to exhaust gas and coolant. The aim of researchers is to analyze the engine which is in production and confirm their suitability for meeting future emissions norms with minor modifications to meet Sustainable Development Goals(SDG).

Vehicle aesthetic appearance is critical factor in the perceived quality of a vehicle. Auto OEM focuses on the improvement of perceived quality. The perceived quality of a vehicle is improved by achieving a superior finish on the visible parts. Plastic parts used in visible areas are painted to achieve a superior finish & aesthetic. However, the painting process is very energy intensive, releases a lot of harmful VOCs into the environment, emits carbon di-oxide into the environment & is a very costly process. Also, painted parts pose a challenge for recycling at the end of life. For painting one square meter area, around 6.5 Kg of co2 is released. Additionally, the painting cost contributes to around 60 % of the part cost. As the emphasis has increased on sustainability & reducing the cost, we took the challenge to develop novel mold in color material to eliminate the painting process without compromising the aesthetic & functional requirements of part. The challenge was to develop the mold in color (MIC) material having a similar appearance as the painted part with no compromise on functional performance and use the existing injection molding tool. This paper explains the development methodology of MIC material & application validation methodology to ensure a similar aesthetic & functional requirement as painted part.

Improving fatigue resistance is a key factor to design components for advanced vehicle transmissions. The selection of materials and heat treatment plays a crucial role in controlling fatigue performance of power transmission components such as gears and shafts. Traditional, low frequency fatigue testing, used for identifying fatigue limit or generating S-N curve for multiple sets of material parameters is highly time consuming and expensive. Hence, it is necessary to develop the capability to predict fatigue performance of materials at different loading conditions with limited amount of data for instance the hardness and inclusion size. In the present work, we have evaluated behavior of the carburized steel subjected to axial and torsional cyclic loading conditions at low frequencies. The effect of different loading conditions is reflected in fatigue life curves (S-N curves), which provides correlation factor given as τ/σ = 0.841 ± 6%, between cyclic torsional stress and axial stress amplitude. Further, using scanning electron microscope (SEM), fracture morphologies were analyzed. It was revealed that, during axial fatigue testing two types of failure modes were obtained i.e., sub-surface and surface failures; while in torsional fatigue testing, failures initiated at the sample surface and exhibited a spiral fractured morphology. Model of Liu is utilized to predict the S-N curve during axial cyclic loading where size of sub-surface defect i.e., inclusion and material hardness were provided as input variables. Moreover, with the help of derived correlation factor, the S-N curve during torsional cyclic loading was derived. It is found that the predicted S-N curve, and experimental results are in good agreement. Altogether, this work provides an approach to derive S-N curves using metallurgical properties during two different loading conditions for carburized steel.

Interdiffusion analysis in multicomponent alloy systems plays a pivotal role in controlling various processes and in designing materials. Interdiffusion of elements also leads to changes in microstructure and properties during service, especially for the materials operating at elevated temperatures. The urge of increasing efficiency of gas turbine engines has led to the demand of higher service temperatures and longer life, which is achieved by the application of thermal barrier coatings (TBC) on Ni based superalloys. To prevent oxidation damage to the superalloy substrate, bond coats are used in which diffusion acts as a key factor influencing the stability and durability of the engine components. Over the last few decades, β-(Ni,Pt)Al coatings have been widely employed as bond coat materials because the presence of Pt enhances oxidation resistance by accelerating diffusion of Al to generate a continuously growing TGO (Thermally grown oxide) layer. However, this also encourages the interdiffusion of Ni and Al between the bond coat and the substrate, which weakens the TBC system. Therefore, a thorough understanding of diffusion behaviour is required in the bond coat materials. In the present study, ternary interdiffusion coefficients are determined in β-(Ni,Pt)Al at 1100 °C. Knowledge of such diffusional interactions would further open new avenues to design bond compositions and process sequences in order to minimize the microstructural changes caused by interdiffusion processes in service.

Globally, automotive sector is moving towards improving off-road performance, durability and safety. Need of off-road performance leads to unpredictable overload to powertrain system due to unpaved roads and abuse driving conditions. Generally, shafts and gears in the transmission system are designed to meet infinite life. But, under abuse condition, it undergo overloads in both torsional and bending modes and finally, weak part in the entire system tend to fail first. This paper represents the failure analysis of one such an incident happened in output shaft under abuse test condition. Failure mode was confirmed as torsional overload using Stereo microscope and SEM. Application stress and shear strength of the shaft was calculated and found overstressing was the cause of failure. To avoid recurrence of breakage, improvement options were identified and subjected to static torsional test to quantify the improvement level.

A lightweight multi-material combination of steel and aluminium alloy (Al) is becoming a novel approach towards environmentally sustainable transport systems. Studies show that 10% reduction of vehicle weight results into 3-7% reduction in specific fuel consumption in IC engines and a 13.7% improvement in electric range for electric vehicles. However, dissimilar welding of Al/steel is a key challenge because of incompatible thermo-physical properties (melting point, thermal conductivity, and coefficient of thermal expansion) and low miscibility between Al and steel. The formation of brittle and hard Al-steel intermetallic compound (IMC) at the joint interface is the major concern for dissimilar welding of Al/steel. In this work, efforts are made to check the feasibility of Ni interlayer to control IMC formation at the interface of Al/steel dissimilar welded joint. Resistance spot welding is used to join low carbon steel CR01 and Al AA6061-T6 with pure Ni interlayer. Microstructure and IMC morphology of welded joints are investigated by optical and scanning electron microscope. The mechanical performance of welded joints is evaluated by tensile shear strength (TSS), failure energy and failure mode. Ni-interlayer does not have major effect on physical aspects of weld such as electrode indentation, Al thinning and steel bulging height. Two separate interfaces namely, Ni/Al and Ni/steel are formed with Ni interlayer. Higher amount of expulsion is taken place at the Ni/Al interface, resulting into lower TSS for dissimilar welding with Ni-interlayer compared to without interlayer.

Surface engineering is becoming increasingly crucial for several automotive and aerospace components that involve intense surface interactions. Friction stir processing (FSP) has emerged as an effective surface modification and hardening technique in recent days. The technique also allows the incorporation of reinforcement into the modified surface to enhance the strength and hardness further. This work applied FSP to develop a pure Ti particulate reinforced AA6061 metal matrix composite (MMC). Six different strategies were adapted (in the form of micro grooves, micro drills on the surface) to effectively infuse reinforcement on the alloy surface. Microstructural changes before and after FSP were studied using SEM and EBSD. Other tests such as post-mortem EDS, XRD, hardness, and compression were also done to examine the performance of developed composite. Microstructural lineaments revealed a more uniform dispersion of reinforcement particles in the matrix when the particles were impregnated using a multi-groove approach. Details on the development strategy, microstructural evolution and various strengthening mechanisms involved in enhancing the mechanical properties are presented in this manuscript.

Motor grader is self-propelled, versatile machine widely used for road construction and maintenance in mining and construction applications. It required working in rugged terrain with uneven and slippery surfaces. Probability of rollover in motor grader is more due to the vehicle profile and high centre of gravity.In light of the above, Roll over Protective Structure (ROPS) is essential to safe guard the operator from any fatal injuries / life during the operation of the equipment at different terrain conditions. Considering DGMS (Directorate of General Mines and safety) requirements, a rugged two post Rollover Protective Structure (ROPS) was designed as per ISO 3471 criteria for ROPS and Falling object Protection Structure (FOPS) as per ISO 3449Material selection for ROPS and FOPS is one of significant factor in design process by meeting the design criteria. It should have dual characteristic, firstly, it is expected to tough enough to withstand sudden impact forces. Secondly, it should flexible enough to absorb the majority of energy during roll-over accidentA 3D model of the Roll over Protective Structure along with FOPS was created and the structure was analyzed using implicit finite element analysis (FEA) software to determine the force-displacement characteristic of Roll over Protective Structure.Material performance requirement, Design and Simulation activities were studied. The Roll over Protective (ROPS) and FOPS Structure for Motor grader was manufactured and fitted on the equipment.

The Tractors are inevitable in the world due to its remarkable contribution majorly in farming process and other applications. the farming equipment needs to perform multiple applications to enhance the productivity and increased horsepower demands all-wheel drive (Refer fig. 1) or four-wheel drive option in the tractor. So, it is becoming a mandatory feature. The main objective of this study is, improving the torsional fatigue life in front axle spindle shaft by modifying the spline design and optimizing induction hardening heat treatment process in such a way that the other part of the system will have a minor or no design change. It helps us to reduce the part count variability, lower manufacturing cost and development time.The spindle shaft with undercut design and profile modified design were subjected to tortional fatigue test with same loading conditions to understand the fatigue life cycle difference between two designs at the load of 700kgm as per DVP, the current spline design covered 2.51L, 2.05L cycles whereas modified spline design samples withstood 5.58L, 3.70L cycles. A remarkable improvement in fatigue life cycles were noticed. As a result, it is evident that the under-cut in spline design acts as a low strength member in the whole shaft which initiated crack and subsequently failed. On the other hand, modified spline end allows the carrying higher load and smooth load transfer which helps to withstand comparatively a greater number of cycles. This paper is having detailed information about the failure history, metallurgical failure analysis, manufacturing limitations, design modifications, heat treatment and validation.

Due to the emerging technologies and globalization, expectations of the customers on commercial vehicles are getting increased over the period. It is an important duty of an OEM to deliver a perfectly configured product to suit the customer requirements. When it comes to configuration of a vehicle, engine power is one of the key factors which indicate the performance of that vehicle. There is a tough competition between every OEM to increase the engine power for enhancing the overall operational performance. One method to increase power is to improve its volumetric efficiency. This is achieved with help of turbocharger and Charge Air Cooler (CAC). CAC improves volumetric efficiency by increasing intake air-charge density. Any failure on CAC leads to lower the volumetric efficiency and increase in turbocharger loading. This paper deals with the validation of CAC assembly using different test conditions by analyzing potential failure modes against the field issues. Optimum test conditions were derived and combination of various loads i.e. Vibration, pressure & thermal were simulated simultaneously during the validation. Test results were analyzed and discussed in detail.

Tensile Testing is one of the most used and highly reliable method of mechanical testing to evaluate the tensile properties of the material. However, there is a large scope for discussing the behavior of the metals based on the direction of rolling and the tensile specimen size used for testing. This paper discusses the variation observed in the tensile values along the direction of rolling and traverse to the direction of rolling for S460MC. It also evaluates the variation observed in the values based on the various gauge lengths (GL) commonly used in testing as per international standards (80mm, 50mm and 25mm GL).It is observed that perpendicular to the direction of rolling, the Yield and Tensile strength of the material increase marginally while the Elongation percentage (%E) decreases by a small margin irrespective of the gauge length taken into consideration. With respect to Gauge Length, it is observed that as the gauge length decreases, in general there is a decrease in strength but increase in elongation irrespective of the direction of rolling.

In most cases, the properties of a metal are evaluated in their as rolled condition, prior to any work hardening or bake hardening. But in the Automotive World, these steels get work hardened during the forming process and bake hardened in the paint shop. The goal of this paper is to evaluate the variations in the performance of Dual Phase (DP) steels and understand the most optimized method of testing and property generation. This method can then be used to extrapolate to real automotive components. Dual Phase Steels or DP Steels contain a mixture of Ferrite & Martensite from which they derive their name. They are a part of the advanced high strength and ultra-high strength steels steel family according to World Auto Steels. The Ferrite phase, with its iron content contributes to the material displaying an increased level of ductility whilst, the martensitic phase provides the steel with increased mechanical strength. These two properties together enable the steel to be highly desirable in the automotive industry with varying uses from being used as Body Panels to Crash critical components. These two critical part sets of the vehicle are often heavily simulated and tested. Over the course of this paper, we will try to understand the effects of work hardening, also referred to as Pre-Straining and bake hardening on two popularly used DP Steels. DP grade steels, ISC590Y and ISC780Y were used for the study. The aim of the study is to understand the effect of bake hardening, effect varying levels of work hardening and bake hardening on these steels and correlate it to the base data which is used in simulations. It is also important to try and understand the optimum degree of work hardening that might be required to gain the most out of these steels.

The usage of forging a preformed, near net shape, compacted and sintered metal powder has been widely accepted since the eighties and is now one of the mainstays for producing Connecting rods in North America. However, its use in Indian subcontinent is limited as its counterpart i.e. conventional steel forging is still the most dominant. Powder metallurgy route has many advantages like good dimensional accuracy; minimum scattering of weight etc. Despite these advantages, the Powder metallurgy process is still not preferred predominantly due to technical (endurance) and infrastructural limitations. This work envisages combining the benefits of powder metallurgy process with the required mechanical properties viz. tensile and fatigue strength alongside design modifications to meet the requirements of a connecting rod for a 2-cylinder diesel engine. The connecting rods met the fatigue life at the required FOS equaling the performance of a conventionally forged connecting rod.

With the introduction of CAFÉ norms (Corporate Average Fuel Economy or Efficiency) in automobile industries, gasoline engines must improve their fuel economy by reducing overall CO2 footprints. To fulfil this demand many OEMs have adopted the use of exhaust gas circulation coolers (EGR)Most of the gasoline engines are having exhaust gas temperatures ranging from 650-850°C, these gases could also be highly corrosive in nature. It’s very important to select the right grade of stainless steel which should have high corrosion resistance and oxidation properties. It should also withstand high temperatures and should have low sensitization at high temperatures.Most of grades stainless steel offers high resistance against corrosion, high temperature properties. But good sensitization at high temperature is not always associated with all grades of steel.To compare corrosion resistivity, PREN number (Pitting Resistance Equivalent Number) plays important role. Highest the PREN number highest is the resistance to corrosion. Based on initial screening SS316L and SS444 grade are selected to undergo various test to demonstrate and compare corrosion, oxidation, and sensitization properties.These materials have gone under various tests like condensate corrosion test as per VDA 230-214 K-1.2 standard, for 1000 hours. After each test, material microstructure properties have been analysed and results are compared. This technical paper includes advantage of material grade in terms of austenitic vs ferritic, manufacturing process, joining process (weldability or brazing), cost and the application where is it most suitable to use.

Requirements for high-reliability lead-free solder alloys in automotive electronics are becoming more challenging as assembly designs require increased powder densities and miniaturization in combination with harsh operating conditions. Thermal cycling performance has been the primary factor for deciding on the suitability of a solder alloy for such applications. Solder joint reliability under thermal and mechanical stresses depends on the solder, packages, PCB, and assembly, including global and local CTE mismatch.Automotive electronic assemblies for critical applications commonly require operational temperatures around 150oC, while soldering temperatures need to be as low as possible (oC). To resolve performance gaps in Sn-Ag-Cu solders for such applications, alloying additives can be used for: i) lowering the melting temperature, ii) improving creep properties, and iii) improving fatigue life. This is exemplified here by comparing a high reliability alloy, commonly known as “Innolot” and SAC305. This work reviews some of the aspects related to such board level accelerated reliability tests and discusses these experimental results in terms of alloy composition, microstructure, and mechanical properties.

Fuel tank is considered as safety component in the vehicle, and it has to be tested to meet the safety requirements as per AIS 095. Earlier, fuel tanks were manufactured by using Hot dipped cold rolled steel material and the weld zones are applied with Anti-corrosive coating. Few fuel tanks were reported with Corrosion problems. The root cause analysis was carried out considering the raw material, manufacturing process, transpiration, storage and usage. As an improvement, the new fuel tank is designed to eliminate the limitations of the existing fuel tank. 3D modeling was done to check space and mounting requirement in the layout and used for volume calculations. FE analysis was performed to check structural stability. Emphasis given on Interchange-ability to cater the new fuel tanks in place of old as spares requirement. The fuel tank has developed with Alumina steel material. Alumina steel is a material with the strength property of steel and corrosion resistant property of Aluminium. The complete manufacturing process has critically studied and new check points and inspection stages were introduced. The Limitations of existing fuel tank has been taken in to consideration and the additional new features were introduced. After successful development, the fuel tank has submitted to M/s Global Automotive research centre for Type approval. The Alumina steel fuel tank underwent hydraulic test and over turn test as per AIS 095: 2007 and type approval obtained. The fitment and functional test was carried out on vehicle and regularized as a standard fitment.

In today’s Automotive world, there is NO need to advocate “Light weighting”. Government policies for carbon footprint reduction combined with high safety standards are driving OEMs to adopt advanced manufacturing technologies.Steel hot forming is selected as most preferred way to reduce weight as it is easy to adopt and commercially known. It had many advantages compare to conventional cold stamping of standard and high tensile steel. The process consists of heating blank to nearly 1000 °C and quenching it in tool to for martensitic structure. Higher strength up to 2000 MPa can be achieved by this process. There are many examples where part weight is reduced by 15 to 20 % by this method.But Steel hot forming has limitation as specific density of steel is still high. Thus, there is limitation to its weight reduction capability. For further reduction, OEMs have started exploring Aluminium hot forming. This process, similar to steel hot forming improves hardness of the part by series of heating and cooling cycles.Aluminium has been used in car for a while but mainly into cold forming and specifically to A and B class panels. Some efforts are made to produce Aluminium die cast parts for chassis. The main advantage was to have jointless parts, but the big disadvantage was “wall thickness” limitation of die casting process. Also, commercial viability is also a big question for large die casting parts.Now hot form aluminium is used for Body-in-White which are strength driven applications. Aluminium hot forming is slowly making its way in mass production with many developments in process optimization. But in India, it has many challenges. “Raw material availability”, “New Technology”, “Tooling Know how” are some of the challenges in adopting this technology in larger scale.A case study will explain the advantages of Aluminium Hot forming, specifically the HFQ® process.

The present work focusses on development of AlSi10Mg alloy component from the pre-alloyed powder by laser powder bed fusion (LPBF), one of the popular additive manufacturing technologies. The effect of heat treatment on microstructure and mechanical properties has also been studied. In accordance with T6 heat treatment process, the LPBF specimens were solution treated at 535°C for 2 h, then water quenched and subsequently, artificially aged at 160°C for 10 h. The role of printing direction on microstructure and mechanical properties has also been investigated. The printing parameters such as laser power, scan speed and hatch space were optimized for defect free automotive component. The as-printed and heat treated components were subsequently evaluated to assess their performance.

Leaf springs are used for vehicle suspension to support the load. These springs are made of flat sections of spring steel in single or in stack of multiple layers, held together in bracketed assembly. The key characteristics of leaf spring are defined as ability to distribute stresses along its length and transmit a load over the width of the chassis structures. The most common leaf spring steels are carbon steels alloyed with Cr and micro-alloyed with Ti, V and Nb. The specific thermomechanical process and alloying elements result in specific strength and fatigue properties for spring steels. The unique properties which facilitate use of spring steel in leaf spring suspensions are ability to withstand considerable twisting or bending forces without any distortion. The microstructure of these steel determines the performance and reflects the process of steel manufacturing. The performance is mainly determined by evaluating fatigue life durability. The microstructural phases mainly precipitate of carbides play a vital role in fatigue life. At one side, controlled size and morphology helps in performance whereas coarse size of the precipitates is detrimental to fatigue life. In this work, attempt was made to characterize the microstructure which includes TiN precipitates and various steel phases. Detailed analysis on TiN particle size and morphology was carried out. Optical microscopy and Electron microscopy along with EDX analysis were utilized for characterization. The microstructural details were also correlated with fatigue failure of leaf spring.

Structural automotive components are subjected to fatigue damage under cyclic stresses and strains. The fatigue damage initiates at stress levels lower than the elastic limit of the material and results in cracks. The Initial fatigue cracks are difficult to detect, such cracks can develop rapidly and cause sudden and brittle failure in structures. Many structural automotive components are fabricated involving weld induced local conditions such as geometry of weld toe and localized tensile residual stresses. These conditions are favorable for initiation of fatigue damage at weld toe.In current work, sever plastic deformation (SPD) which is based on high frequency impact treatment using ultrasound energy was applied on weld toe of representative weld joints. The effect of SPD on weld toe geometry modification, microstructure and residual stresses were evaluated. Microscopic and X-ray diffraction techniques were used to study the effects of SPD. It was observed that SPD can significantly refine the weld toe geometry and induce compressive residual stresses, which can potentially improve fatigue life of weld joint.

In an automotive vehicle, the Window Regulator is an electro-mechanical assembly that is mounted inside the door. The basic function of the Window Regulator is to raise or lower the glass when required and hold the glass in closed position or in any desired position. During Water servicing or rains, Water will typically enter inside the door through the seals and on to the Window Regulator mechanism. Hence these conditions must be physically tested in the laboratory to assess the Window Regulator’s functionality which could get affected by Water intrusion. The Water spray test conditions are based on mutual agreement between Inteva Products and the OEMs.Water spray test involves moving the electric Window Regulator to upper stall position (Window closed) at a defined voltage and line resistance. The glass must be dwelled followed by spraying defined amount of Water which simulates the rain. The agreed number of test cycles would be around 4500 which lasts about 7 weeks. Hence, to prepare this test setup, a large area of floor space along with other testing peripherals were to be procured and this would involve good amount of space, cost, Water, and time. Hence the Test Lab team developed an economical in-house test setup using available resources and equipment to reuse and recycle which will lead to significant savings.This test setup developed to conduct Water spray test was carried out by using the available electric control box and mechanical infrastructure along with re-circulation of Water. The primary objective of this test setup was to comply with the test requirements along with Water reusage. This significantly reduced the new procurement / development cost and time since the available resources in the test lab were reused (80% of the materials were used from inventory, available in-house and from multipurpose devices and 20% were purchased).

FEA based simulations are extensively used in automotive industry for improving the product design and reducing the time taken for design and prototyping. FEA based simulations require material data as an input in form of material models. Most commonly used material models for simulation of metallic materials are elastic models and elasto-plastic models, which provide very good correlation till ultimate tensile strength (UTS). For simulation beyond UTS value, elasto-plastic material model has to be used along with material model considering the damage accumulation post UTS. For crash like event in automotive crash, required material models should consider the effect of various stress state conditions (Triaxiality) and strain rate sensitivity of materials along with damage accumulation. In LS Dyna solver, MAT_ADD_EROSION material model (GISSMO) along with MAT_024 is widely used for these applications.This paper will focus on development of GISSMO material model card for advanced high strength steel. Various stress state conditions will be considered along with strain rate sensitive properties. Paper will also cover the MAT_024 material model card which is used in association with MAT_ADD_EROSION for elasto-plastic region. Simulated data of coupons and component will be validated with experimental results.

The dump body of the off-highway dump truck is the large, prime structure, used to carry overburden and coal in mines. The body structure is subject to severe vibration, impact load, and oscillation events due to rough terrain conditions in the mines and the loading of rocks from a certain height from the shovel. Presently, the body mounting design is chassis pivot pin mounted, rubber rail seated, and has guide plates to lock transverse movements. Despite all these mounting arrangements, the body structure oscillates (or rattles) due to multiple field factors. The most effective solution to the problem is to provide an additional oscillation-arresting structure so that body stability is achieved and undesirable body-frame impact is avoided. The prime objectives of this study are to design an additional oscillation-arresting structure and to select an appropriate material to work at an ambient temperature of -50°C (sub-zero temperature); to carry out the structural behaviour of the existing material (works in normal temperature). The structural design is validated through classical hand calculations and Finite Element Analysis (FEA), qualifying it by Von Misses stress, shear stress, and displacement criteria. Recommending the most suitable material for sub-zero temperature (-50°C) application.

Rubber is one of the most versatile materials and finds numerous applications in diverse areas. The application of rubber is mostly determined by its physico-mechanical and viscoelastic properties. Rubber properties play an essential role in performing its functional requirement, which is crucial for designing a good rubber product. Therefore, the estimation and prediction of the properties of rubber and rubber composites are central to the material developers. However, many factors, such as temperature, environmental effects, and rubber formulation can influence rubber properties and make it highly non-linear. Computer simulation plays a vital role in our understanding of complex dynamics in rubber materials and provide structure-property relationship at the nanoscopic and microscopic level. An understanding of this relationship can reduce the expensive trial experiments and provide a benchmark for novel material design. Additionally, simulations at atomic and molecular levels provide the mechanism of action and the underlying physics which finally helps in designing of new materials. In the present work, all atomistic Molecular Dynamics (MD) simulation technique is utilized to predict various thermodynamic and viscoelastic properties of raw rubbers. The effect of key structural factors, that govern the properties of rubber at the molecular level, is examined using MD. In this work, we have developed the classical atomistic models for several raw rubbers and implemented methodologies for calculating their properties from MD simulations. The predicted properties using our model and methodologies are in close agreement with the experimental and available literature values. Our results establish that MD simulations are an effective tool to predict quantitatively thermodynamic and viscoelastic properties of rubber. Eventually, the same technique can be used to predict properties for crosslinked rubber, rubber composites, blends, and silica/carbon black reinforced rubbers and thus, designing a novel rubber material.

Historically manufacturing variability has been considered as a noise factor due to limited insights about manufacturing history and its influence on part performance. With improvement in computational power and enhancements in commercial simulation tools, it is now feasible to study the influence of manufacturing process on product life in addition to manufacturability. This study demonstrates the concept of as manufactured part performance prediction utilizing forming simulation software to capture deformed geometry along with residual stresses and its integration to performance simulation tool using sheet drawing operation. Simulation predictions are verified and validated with available experimental data.This approach helps to visualize the variation in part performance with respect to manufacturing process change including process sequence, process parameters and tooling design change. It further helps to create integrated digital model enabling design optimization thereby reducing product cycle time and physical trials.

Materials play a key role in our day to day life and have shaped the industrial revolution to a great extent. Right selection of material for meeting a particular objective is the key to success in today’s world where the cost as well as sustainability of any equipment or a system have assumed greater significance than ever before. In automotive industry, materials have a definitive role as far as the mobility and safety is concerned. Materials that can absorb the required energy or impact can be manufactured through different manufacturing as well as metallurgical processes which involves appropriate heat treatment and bringing correct chemical compositions etc. However, they can also be formed by simpler methods such as combining certain materials together in the form of layered combinations to form light weight composites. Analyzing the response of different materials during incidents such as high-speed impact or transmission of shock waves as a result of earthquakes, tsunami or manmade disasters like explosion, is of great importance. Those materials which can respond in a desirable manner to meet a particular requirement during the most undesirable conditions such as high energy impacts can be termed as high energy absorbing materials and they play a crucial role in designing important structures, frames, protective vehicles and equipments, sacrificial components and claddings etc. These materials and structures need to be tested for their strength and design against adverse loading conditions. In this paper, different materials like steel, aluminum and aluminum-rubber combination are analyzed to understand their response during high pressure loading incidences. Judicious and scientific application of these materials can ensure a much better protection to different structures of importance, buildings as well as in defence, aerospace and automotive related applications. There are different methods of analyzing the strength and capabilities of materials or their combinations such as experimental, lab and simulation method. Out of these, the simulation (numerical analysis) method is one of the most appropriate methods which give very accurate results as compared to other methods. Here, Ansys- Autodyn simulation is used to draw the analysis of the materials and their combinations under high pressure shock loadings, resulting due to explosion or blast, and the total energy, pressure, displacement and velocity parameters are studied and compared.

The clean nature of hydrogen as an energy source is propelling the rapid development of applications and infrastructure for its production, storage, and distribution. One of the challenges for the widespread adoption of hydrogen as a fuel is identifying materials that can safely handle high pressures of hydrogen. Hydrogen Embrittlement is a well-known but not very well-understood mechanism of material failure in such applications. This paper gives a literature review of hydrogen embrittlement and the test methods that can be employed for measuring and qualifying materials for hydrogen applications. Slow Strain Rate Testing (SSRT) and fractography results for three austenitic steel grades performed at 85-87.5 MPa hydrogen pressure are described. Grade Alleima HP160 showed good resistance against hydrogen embrittlement despite its low Ni content compared to the two UNS 31603 alloys with different Ni contents. The results are interpreted in light of the Nickel equivalent of the alloys.

The automotive industry is facing a challenge as efficiency improvements are required to address the strict emission norms which in turn requires high performance downsized, lightweight IC engines. The increasing demand for lightweight engine needs high strength to weight ratio materials. To meet high strength to weight ratio, castings are preferable. However due to strength limitations for critical crankshaft applications, it forces to use costly forgings such as micro alloyed forging steel and Martensitic (after heat treatment) forging steel. To reduce the cost impact, high strength Austempered Ductile iron (ADI) casting is developed for crankshaft applications to substitute steel forgings. Austempered Ductile Iron is having an excellent mechanical properties due to aus-ferritic structure. The improved properties of developed ADI Crankshaft over steel forged crankshaft offers additional weight advantage. The ADI Crankshaft was subjected to rig test and meets the fatigue and durability life at the required Factor of Safety.

The primary objective of this work is to design new type of silencer with perforated inner pipe and nozzles for reducing the sound pressure level in automobile engine. Initialy, the proposed silencer with perforated inner pipe and nozzles was designed and analyzed by using ANSYS-Fluent (Workbench). In this analysis the effect of number of nozzle, convergence angle and position of nozzles were investigated. Based on the simulation results the proposed silencer with perforated inner pipe and nozzles was fabricated. Meanwhile conventional type silencer (with perforated inner pipe and without nozzle) was also fabricated. Both type of silencer were tested in a Kirloskar single-cylinder water-cooled 10hp diesel engine. The sound produced through the outlet of the silencer was measured using the SPL application on the mobile device. The experimental results shows that the silencer with perforated inner pipe and nozzles was having lower sound level and lower engine's backpressure.

Safety of a battery pack of an electric vehicle against impact is necessary as it possess a severe fire hazard. In this paper, a computer aided simulation is conducted to optimize the weight of a battery pack assembly. A numerical model, using commercially available FE code Abaqus, has been developed and studied against different load cases, crush, mechanical shock, and underfloor impact. The acceptance criteria of each test are studied, and the integrity of the design is checked against each test. The weight of the battery pack enclosure was reduced while keeping crashworthiness intact.

Side door latches in an automotive play a major role in occupants’ safety. The latches consist of both retention assembly and actuator assembly. The actuator assembly majorly consists of motor, gear & other components and these are protected through a Plastic Lower case and Housing. The Lower case (over-mold) with the Electrical Component Carrier - ECC (pre-mold) plays an important role in providing electrical power supply to the latch system. Since these parts are manufactured with terminal traces & plastics, upfront mold flow simulations help the product teams to evaluate the short fills, warpage, and other quality aspects in the critical areas of these components.In the part assembly station, the ECC (pre-mold) and the Lower case (over-mold) are connected to the Motor on one side and the Connector on the other. The proper alignment of the pre-mold pins is of great importance and the pre-mold must not be externally visible once the molding is complete. During the prototype build, the pins were offset/dislocated due to pre-mold shift. This in turn caused deformation of the Over-mold resulting in dimensional inconsistency leading to assembly & functional issues.This issue was complex since the part couldn’t be modified structurally because of the constraints in packaging as these interfaces with the backplate & the child feature would affect its integrity. Here, overcoming the ‘pre-mold’ shift was an important aspect to keep the Lower-case pins within the location limits ensuring a proper part assembly. However, it was challenging to control the ‘pre-mold’ shift defect merely based upon the molding manufacturing knowledge. Hence, we had to utilize ‘core-deflection analysis’ method in Moldex-3D, an injection molding specialized software, to verify the cause of ‘pre-mold’ shift and correct the problem. Virtual simulation technique has helped to resolve the issue and same technic was used in production tool. This paper will provide an insight to both the methodologies used and the tooling changes required to achieve the product assembly requirements.

Energy dispersive X-ray fluorescence (EDXRF) analysis have made it possible to conduct elemental analysis on a variety of fields, including those with environmental, automotive, geological, chemical, pharmaceutical, archaeology, and biological origins. The ability of EDXRF to deliver quick, non-destructive, and multi-elemental analytical findings with increased sensitivity is of great importance. It is a vital tool for quality control and quality assurance applications. Thus, EDXRF plays an important role to compare batch-to-batch products for meeting quality standards.This paper presents application of EDXRF as an effective tool for quick qualitative and quantitative evaluation of given samples. A few simple case studies demonstrating application of EDXRF are presented, which includes identification of the filler contained in the polymer, coating thickness, elemental composition of the particulate matter collected on filter paper, multi-element analysis of printed circuit boards (PCB) and a delamination case. Such type of rapid and non-destructive technique provides an effective means for analysis of variety of materials used in automobiles.

A gear is an essential component of a mechanical transmission system. Its design and reliability have a great influence on the system service life. The design of a gear pair is generally done using various design criteria and constraints. At the design stage, since the future operating profile in terms of terrains, load transitions and speeds are unknown, one method for extending the life of a gear teeth is to use a high safety factor. Unfortunately, this strategy is not always acceptable because it not only adds unnecessary weight but also increases the cost. In this paper, a machine learning technique is used to generate operating profiles that a gear pair can experience in the future. The proposed method is based on the N-grams algorithm which is extensively used in Natural Language Processing to predict the next word on the basis of the order of the previous words. In the current work, three different terrains are considered, each with a range of torque from 1000 Nm to 9000 Nm. This range of torques is further segmented into five subranges, where each subrange of torques represents a state. A state in a particular terrain has its own random exponentially distributed residence time. The future path would be the combination of different load states. The generation of sequence of states in a terrain is accomplished using N-gram. The method proposed is practical and applicable at the design as well as for prediction of residual useful life of the gear pair.

The prediction of accurate evaporation rates for aviation fuels, which are complex mixtures of hundreds of hydrocarbon components with varying evaporation characteristics, remains a challenge. Multi-component vaporization models, such as distillation curve (DC) and diffusion limit (DL), are capable of predicting evaporation rates well but require the construction of surrogate fuels, which is difficult. Mono-component models, on the other hand, can be used for rapid evaporation conditions similar to those in a heat engine combustion chamber, with acceptable uncertainties. However, the accuracy of these models under engine-relevant operating conditions is unclear. This study aims to address this research gap by experimentally measuring the evaporation rates of two aviation fuels (TS-1 and Jet-A1) at different temperature conditions and evaluating the feasibility of current theoretical models for predicting evaporation rates under engine-relevant conditions. The study found that current models cannot accurately describe special events such as micro-explosions or slow evaporation, which were observed in the case of TS-1 droplets at temperatures above 823 K. This study highlights the need for more accurate models for predicting the evaporation rates of aviation fuels under engine-relevant conditions.

This paper describes lightning fuel ignition source test data on cracked aluminum and hydraulic tubes. The tube test articles included several different types of cracks and establish ignition source threshold current densities that exceed what is expected in traditional aluminum fuel tanks for midsize business jets, which notably are higher than typical current densities in larger Part 25 airplanes. Additionally, the fuel tube test data compared to ignition source current thresholds associated with tube couplers and fittings show consideration of cracks in the tubing will not typically be a critical factor in showing compliance or determining design constraints.

To cope with increasing, challenging requirements and shorter development cycles, more complex, often nonlinear, systems with high interactions have to be optimized in many fields of research, such as the energy sector. As this often goes beyond the classical parameter studies-based approach, systematic optimization approaches offer a key solution. In the context of the development of energy converters, like engines, such techniques are applied to enhance efficiency and enable optimal use of energy. This review provides a comprehensive overview of the field of optimization approaches, more precisely referred to as Metamodel-Based Design Optimization (MBDO). The MBDO approaches essentially comprise three main modules: the Design of Experiment (DoE), the Response Surface Modeling (RSM), and the Multiobjective Optimization (MoO), in varying compositions. Previous reviews primarily focused on a selection of these modules, whereas this novel review equally covers and structures the modules DoE, RSM, and MoO and their combination to MBDO approaches. Many examples of these modules and MBDO implementations and their interrelationship, strengths, and limitations are discussed in detail and supplemented with many exemplary methods, e.g., from engine development. Methods from previous reviews are collected and updated with recent approaches, e.g., including new machine learning methods used in this context. Moreover, this study presents a holistic, extended classification approach to structure any MBDO method. The classification, which is based on the existence, structure, and interactions of the modules DoE, RSM, and MoO, is applied to various MBDO approaches from the literature. One recent MBDO focus of research is the development of online adaptive approaches as these allow to use valuable information obtained during the optimization process to guide the DoE or MoO. Therefore, the online adaptivity, feedback loops, and strengths and limitations of MBDO approaches are a novel focus area of this review. Recommendations and requirements for future “Fully Online MBDO” approaches with enhanced adaptability and generalizability are derived.

The transport refrigeration market is in a transformation like what automotive experienced over the last 20 years using a systems engineering approach complemented with complex attribute optimization to manage product development. With a heavy push for electrification due to government regulations, sustainability initiatives, and designing the products to align with the OEMs electrified platforms Noise, Vibration, and Harshness (NVH) must be considered. Understanding the above along with refined customer expectations the NVH attribute has become even more critical to product quality. This paper showcases the acoustic design of an electrified system using a system engineering approach to achieve unit level targets deploying a system engineering V-model philosophy. Unit level requirements were set and flowed down to component level requirements. A 1D acoustic tool was developed leveraging classic physical acoustics theory and legacy product knowledge to target set what was possible for various architecture possibilities and rapidly iterate on design choice implications and complete attribute trade off analysis. Component and unit level testing was utilized to refine model parameters and develop a continuous surface to interpolate and extrapolate system performance. Model verification and validation will be discussed along with final unit qualification to meet requirements. Further work on unit noise optimization using the system model will be covered along with future work for model refinement.

In the context of automotive air boosting systems, such as turbochargers and full-cell compressors, earlier and more realistic noise evaluations are crucial in evaluating the impact a design has on the final acoustic performance perceived by the end user in the vehicle cabin environment. This requires a combined assessment of the acoustic sources from boosting systems, other vehicle interior noise sources, and the acoustic transfer path from the boosting system to the vehicle cabin. Performing such an assessment experimentally cannot be done early in development with representative hardware and can be expensive. Also, managing such an assessment entirely through simulations is very complex and error prone.The present study proposes a hybrid approach to tackle this noise challenge. This methodology combines the noises of high-speed rotating machine simulated rotor-dynamic and electromagnetic simulation processes, their transformation from frequency to time domain, and coupling with experimental vehicle noise data. This methodology makes it possible to virtually recreate an acoustics scenario at vehicle cabin level in realistic vehicle operating conditions. This enables earlier, faster, and easier objective and subjective evaluation of noise response as a function of component design changes, vehicle transfer function, and drive cycles, which are critical in determining the right corrective actions to mitigate potential noise risks in vehicle.

Pass-by noise measurement is mandatory for automotive manufacturers for conformity of production. With evolving of pass-by noise requirements (under 68 dB in 2024), all the stakeholders should be able to comply with this criterion. OEMs, suppliers of passive acoustic treatments, road manufacturers and tire manufacturers are concerned and should deploy efforts to provide solutions for control of exterior noise. In this regard, simulations are preferable over measurement campaigns as they can provide fast feedback on passive exterior treatments for exterior noise control. In the particular case of Lightyear vehicles, the main contributors to pass-by noise are tires and in-wheel motors. Considering that, a contribution of each of these two sources of noise to pass-by noise will be described. Tire noise sources and motor noise sources will be replaced by simple monopole sources. The best monopole source location for both tires and motors is discussed. Actran vibro-acoustic Finite Element software is used to predict the noise at pass-by microphones. The calculation process takes advantage of advanced techniques to optimize the process. The acoustic transfer functions (TFs) from monopole sources to microphones are calculated first. The TFs are computed in different conditions considering acoustic treatments in different areas. Finally, these transfer functions are recombined with source strengths from tire and motor monopole sources. The pass-by noise simulation results are compared to the pass-by noise test results to conclude on the simulation accurateness.