Search Results

This paper discusses the methodology setup for grill opening area prediction at the early development phase of the product development lifecycle, using a commercially available 1D simulation tool- AMESIM. Representative under hood has been modeled using Grill, Condenser, Radiator, intercooler, fan, and engine components. Vehicle velocity is used as an input to derive the airflow passing through the grill and other under-hood components based on ram air coefficient, pressure drop through different components (Grill, Heat exchanger, Fan & Engine). This airflow is used to predict the top tank temperature of the radiator. Derived airflow is correlated with airflow obtained from CFD simulation. A balance has been achieved between cooling drag & fan power consumption at different grill opening areas for target top tank temperature. Top tank temperature has been predicted at two different extreme engine heat rejection operating points.

Today’s automotive world has moved towards an age where safety of a vehicle is given the topmost priority. Many stringent crash norms and testing methodology has been defined in order to evaluate the safety of a vehicle prior to its launch in a particular market. If the vehicle fails to meet any of these criteria then it is debarred from that particular market. With such stringent norms and regulations in place it becomes quite important on the engineer’s part to define the structural requirements and protect the space to meet the same. If the concept level platform definition is done properly it becomes very easy to achieve the crash targets with less cost and weight impact.

The focus on driver and occupant safety as well as comfort is increasing rapidly while designing commercial vehicles in India. Improvements in the road network have enhanced road transport for commercial vehicles. Apart from the cost of operation and fuel economy, the commercial vehicles must deliver goods within stipulated time. These factors resulted in higher speed of operation for commercial vehicles. The design should not compromise the safety of the vehicle at these higher speeds of operation. The vehicle should obey the driver’s intended direction at all speeds and the response of the vehicle to driver input must be predictable without much larger surprises which can lead to accidents. The commercial vehicles are designed with rigid axle and RCB type steering system. This suspension and steering design combination introduce steering errors when vehicle travel over bump, braked and while cornering.

Squeak and rattle concerns account for approximately 10% of overall vehicle Things Gone Wrong (TGW) and are major quality concern for automotive OEM’s. Objectionable door noises are one of the top 10 IQS concerns under any OEM nameplate. Door trim significantly contributes to overall BSR quality perception. Door trim is mounted on door in white using small plastic clips with variable properties that can significantly influence BSR performance. In this paper, the performance of various door clips is evaluated through objective parameters like interface dynamic stiffness and system damping. The methodology involves a simple dynamic system for the evaluation of the performance of a clip design. Transmissibility is calculated from the dynamic response of a mass supported by clip. Parameters such as interface stiffness and system damping are extracted for each clip design. Variation of inner panel thickness is also considered when comparing clip performance.

This paper describes application of Design of Experiments (DOE) technique and optimization for mass reduction of a Sports utility vehicle (SUV) body in white (BIW). Thickness of the body panels is taken as design variable for the study. The BIW global torsion, bending and front end modes are key indicators of the stiffness and mass of the structure. By considering the global modes the structural strength of the vehicle also gets accounted, since the vehicle is subjected to bending and twisting moments during proving ground test. The DOE is setup in a virtual environment and the results for different configurations are obtained through simulations. The results obtained from the DOE exercise are used to check the sensitivity of the panels. The panels are selected for mass reduction based on the analysis of the results. This final configuration is further evaluated for determining the stiffness and strength of the BIW.

In the automotive industry the requirement for low emissions has led to the demand for lightweight vehicle structures. Light weighting can be achieved through different iterative approaches but is usually time consuming. Current paper highlights deployment of the multi-loadcase optimization approach for light weighting. This work involves developing a process for multiple loadcase optimization for automotive hood. The main goal is to minimize the weight of a hood assembly by meeting strength and stiffness targets. The design variables considered in this study are thickness of the panels. Design constraints were set for stress and stiffness based on DVP (Design Verification Plan) requirement. Optimization workflow is setup in mode-frontier with design objective of minimizing weight of hood.

In any industry, early detection and mitigation of a failure in component is vital for feasible design changes or development iterations or saving money. So it becomes pivotal to capture the failure mode in an accelerated way. This theory poses many challenges in devising the methodology to validate the failure mode. In real world, vehicle head lamp is exposed to all possible kinds of harsh environments such as variable daily ambient, rain, dust and engine compartment temperature …etc. This brings rapid thermal stress onto headlamp resulting into warpage cracks. At vehicle level on particular model, this failure is typically observed after 20,000-25,000 kms in a span of 3-4 months of running. Any corrective action to revalidate the design change or improvement will need similar timelines in regular way to test, which is quite high in product development cycle.

Designing a vehicle chassis involves meeting numerous performance requirements related to various domains such as Durability, Crashworthiness and Noise-Vibration-Harshness (NVH) as well as reducing the overall weight of chassis. In conventional Computer Aided Engineering (CAE) process, experts from each domain work independently to improve the design based on their own domain knowledge which may result in sub-optimal or even non-acceptable designs for other domains. In addition, this may lead to increase in weight of chassis and also result in stretching the overall product development time and cost. Use of Multi-Disciplinary Optimization (MDO) approach to tackle these kind of problems is well documented in industry. However, how to effectively formulate an MDO study and how different MDO formulations affect results has not been touched upon in depth.

One of the primary excitation sources in a passenger car comes from the powertrain [1]. Refinement of powertrain induced noise is the most critical tasks during a vehicle refinement. Due to ever increasing demand for reduced design and development cycle, most critical decisions have to be made at the concept stage. Powertrain radiated noise is one of the most important performance factor that must be evaluated during the concept stage. Solution time for calculating the radiated noise using the existing acoustic solvers is very high and requires very expensive resources like software and hardware. Arriving the optimal design with conventional method is very tedious job. A new method has been adopted for identifying the critical areas and coming up with the optimal design modifications within a short span of time. Powertrain radiated noise has been calculated with the help of acoustic solver.

The objective of this paper is to minimize occupant injuries in offset frontal crash with pulse characterization, by keeping vehicle front crush space & occupant survival space constant. Crash pulse characterization greatly simplifies the representation of crash pulse time histories. The parameters used to characterize the crash pulse are velocity change, time & value of dynamic crush, and zero cross-over time. The crash pulse slope, peaks, average values at discrete time intervals have significant role on occupant injuries. Vehicle crash pulse of different trends have different impact on occupant injury. The intension of crash pulse characterization study is to come out with one particular crash pulse which shows minimum occupant injuries. This study will have significant impact in terms of front loading on crash development of vehicle.

The SAE J1100 based standard cargo volume index methods and predefined luggage objects are very specific to United States population. The European luggage volume calculation and standard luggage calculations are primarily based on DIN and ISO standards. Luggage volume declaration by manufacturers are based on any of these methods. The calculations are complicated and there is a possibility of declaring different values for similar luggage compartments. The major purchase decision of vehicle is based on its luggage capacity and current methods are very limited to make an intelligent decision by a customer. Market specific customer usage patterns for luggage requirements and protecting them in vehicle architecture upfront in concept stage is important to retain the market position and buying preference of customers. The usage patterns is collected from customer clinics and marketing inputs.

Tractor roll over is the most common farm-related cause of fatalities nowadays. ROPS (Roll-Overprotective Structures) are needed to prevent serious injury and death. It creates a protective zone around the operator when a rollover occurs. In India the ROPS is getting mandatory across all HP ranges except narrow track. In the present study states the customized ROPS application for configurable design such as Automated safety zone for all homologation standards, ROPS A0-D excel calculator for selection of material at concept stage and bolt calculator for selection of size. For the above applications below aspects need to consider such as Tractor weight, Rear housing mounting, Operator seat index position (SIP), Seat reference points (SRP) and all ROPS homologation standards. This ROPS application is to reduce the timeline, manual error and ensure the reliability of the modular optimal design for various platforms and variants.

The ECE R-14, AIS015 safety standard specifies the requirements of the safety belt anchorages namely, minimum numbers, their locations, static strength to reduce the possibility of their failure during accidental crashes for effective occupant restraint and the test procedures. This standard applies to the anchorages of safety belts for adult occupants of forward facing or rearward facing seats in vehicles of categories M and N. ECE R14 ensures the passenger safety during sudden acceleration/retardation and accidents. Early simulations revealed some structural short falls that demanded cabin improvements in order to fulfill regulation requirements for the seal belt anchorage test. This paper describes the innovative design modifications done to meet the seat belt anchorage test. Good correlation with the test is achieved in terms of deformations. These simulation methods helped in reducing the number of intermediate physical tests during the design process.

Vehicle safety and adherence to rules and regulation is of utmost requirement for any OEM. ECE R42 is one of the most important test criteria for a vehicle to get launched. To prove this, we shall discuss the case of Low speed impact structure construction. In this paper, we are going to demonstrate the novel design of Polymer energy absorption structure to meet the rear bumper low speed impact test and ensure proper absorption of impact energy and avoid any damage to rear lamp of the vehicle. This paper shows a perfect example of sustainability with the help of complete modular construction of the frame structure. The proposed design uses a cost-effective way of assembling the physical part by comparing with benchmarking and within the Mahindra part library. The low speed impact structure is mounted directly to BIW panels without any extra foams. These frame structure are simple in design and rigid in construction by comparing with other OEM products and within all Mahindra vehicles.

The spoiler is functional as well as aesthetic part fitted on the vehicles to improve the vehicle aerodynamic performance and better aesthetic appeal. The improvement of aerodynamics performance of the vehicle at higher speeds is achieved by reducing the overall vehicle coefficient of drag. This helps in better handling and improved fuel efficiency of the vehicle thus contributing to development of greener vehicle. In this project, our main focus is to reduce overall vehicle coefficient of drag, Design a light weight spoiler and improve the vehicle aesthetic appearance.

Application of advance composites in place of the various conventional materials such as steel can give significant weight and performance advantages. The application of composites is now finding it’s way in the automotive industry due to the growing requirement of the lightweight solutions and high strength to weight ratio. However, their low mechanical properties have limited their application in automotive structural components. The study presented here is focused on the explicit dynamic analysis of a bumper beam and advance composites are used for the study. Different configurations and designs of the bumper are considered to be able to make a comparative study of the stress and deformation levels. The analysis was done in coherence to the Euro NCAP tests and the offset frontal impact analysis was done. The boundary conditions were aligned with the real time impact conditions for proper prediction of the results.

Brake groan noise is resolved without any major change in the design of brake system and vehicle sub-system components in the development phase of a utility vehicle. The groan noise is observed during the end of the stopping of the vehicle under moderate braking. The concerned NVH issue is perceived as unacceptable noise in the passenger compartment. Groan induced vibration is subjectively felt on steering and seat frame. A typical process is established to successfully reproduce the groan which helped in precisely evaluating the effect of modifications proposed. The temperature range of the disc which has the highest probability to produce the groan noise is found out experimentally. The transfer path analysis is carried out to find the path contributions from suspension. Acoustic transfer functions from considered paths are measured with the suspension removed from vehicle.

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.

In today's automobile market, fuel economy is a powerful parameter which gives an edge over competition. Light weight materials play a major role in achieving this. Mirrors tend to underperform in terms of NVH when they are considered for weight optimization. Being light in weight mirrors get easily excited as the energy gets transferred through the structures causing vibration due to their poor damping characteristics. Mirror vibration is a grave concern which affects the vehicle safety. Blur is an effect of vibration which has higher energy levels in vertical and longitudinal direction. It resembles resonance, wherein the vision is zero at certain engine rpm. This paper depicts the approach for mirror blur elimination in the vehicle (prosper segment vehicles), which consider cost as the primary concern. Since the vehicle was nearing SOP design changes was not possible. Certain parameters were attempted without affecting the design as explained in this paper.

In the current competitive automobile market, with growing knowledge and concern for occupant and vulnerable road user safety, design & engineering of passenger cars in stipulated time is a challenge. As front styling is a crucial factor, early involvement of Computer Aided Engineering (CAE) through front loading helps reduce the product development time considerably with a pedestrian friendly engineered design. The present paper explains how initial inputs are given to styling & engineering teams during early stages of product development where availability of Computer Aided Design (CAD) data is minimal. Critical load paths were identified and shape of the front end was modified accordingly. Various locations of hinge mechanism were evaluated to reduce the severity of injury in the head impact zone. Sufficient gaps between the exterior surfaces and interior hard points were worked upon to reduce the impact values.