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Viewing 241 to 270 of 4645
2015-06-15
Technical Paper
2015-01-2262
Tom Knechten, Marius-Cristian Morariu, PJG van der Linden
Abstract Structural and vibro-acoustic transfer functions still form an essential part of NVH data in vehicle development programs. Excitation in the three DOFs at all body interface connection locations to target responses gives information on local dynamics stiffness and the body sensitivity for that specific path in an efficient manner. However, vehicles become more compact for fuel efficiency, production costs and to meet the market demand for urban vehicles. Alternative driveline concepts increase the electronic content and new mount locations. To achieve the optimum on road noise NVH, handling performance while conserving interior space and trunk volume requires a complex suspension layout. On top of that, customers put weight on safety and comfort systems which result to a higher packaging density. These trends imply ever limiting accessibility of the interface connections on the body structure.
2015-06-15
Technical Paper
2015-01-2127
Andrea Munzing, Franck Hervy, Stephane Catris
Abstract A helicopter blade profile was tested in the DGA Aero-engine Testing's icing altitude test facility S1 in Saclay, France during the winter of 2013/2014. The airfoil was a helicopter main rotor OA312 blade profile made out of composite material and with a metallic erosion shield. Dry air and ice accretion tests have been performed in order to assess the iced airfoil's aerodynamic behaviour. Several icing conditions were tested up through Mach numbers around 0.6. This paper presents the test setup, the test model and some of the test results. The test results presented in this paper include the ice shapes generated as well as dry air and iced airfoil lift and drag curves (polars) which were obtained with the real ice shapes on the airfoil.
2015-06-15
Technical Paper
2015-01-2163
Caio Fuzaro Rafael, Diogo Mendes Pio, Guilherme A. Lima da Silva
Abstract The present paper presents a validation of momentum boundary-layer integral solution and finite-volume Reynolds-Averaged Navier Stokes (RANS) Computational Fluid Dynamics (CFD) results for skin friction around airfoils NACA 8H12 and MMB-V2 as well as heat transfer around an isothermal cylinder with rough surface. The objective is to propose a two-equation integral model and compare its predictions to results from a robust CFD tool, to experimental data and to results from a one-equation integral solution. The latter is the mathematical model used by classic 2D icing codes. All proposed model predictions are compared to CFD results for verification and, whenever possible, to experimental data for validation. The code-to-code verification brings reliability to both the proposed code and the CFD tool when there is no test data available.
2015-06-15
Technical Paper
2015-01-2329
Paolo Di Francescantonio, Charles Hirsch, Piergiorgio Ferrante, Katsutomo Isono
Abstract A new method called Adaptive Spectral Reconstruction (ASR) for the stochastic reconstruction of broadband aeroacoustic sources starting from steady CFD analyses is presented and applied to the evaluation of the noise radiated by a model automotive side mirror. The new approach exploits some ideas from both SNGR and RPM, and for some aspects can be considered as a sort of mixing between the two methods since it permits to reconstruct both the frequency content of the turbulent field (as done by SNGR) and the spatial cross correlation (as done by RPM). The turbulent field is reconstructed with a sum of convected plane waves, but two substantial differences are introduced in respect of SNGR. The first difference concerns the spatial variation of the parameters that define each wave, that depends on the wavelength of each wave, rather than being kept constant or related to the CFD correlation length.
2015-06-15
Technical Paper
2015-01-2324
Hangsheng Hou, Guiping Yue
Abstract When a sunroof opens to let in fresh air while driving, there might be several noise issues associated with it. The most common and painful one is the wind throb issue, which is nevertheless largely resolved by implementing a sufficiently high wind deflector along the front edge of the sunroof. However, with the wind throb suppressed, other sound quality issues might emerge. The most notable one is the hissing noise issue, which becomes increasingly objectionable with the increase of vehicle speed. This work looks into the impact of sunroof deflector on interior sound quality with the consideration of wind throb, hissing noise and booming noise in terms of psychoacoustic attributes that could be felt subjectively. The goal is to achieve a better understanding of the sound quality associated with the sunroof deflector design, and inspire a balanced design, potentially targeting the most NVH demanding customers in the premium vehicle segment.
2015-06-15
Technical Paper
2015-01-2322
Bastien Ganty, Jonathan Jacqmot, Ze Zhou, ChanHee Jeong
Abstract At high cruising speed, the car A-pillars generate turbulent air flow around the vehicle. The resulting aerodynamic pressure applied on the windows significantly contributes to the total cabin noise. In order to predict this particular noise contribution, the physic of both the flow and the cabin needs to be accurately modeled. This paper presents an efficient methodology to predict the turbulent noise transmission through the car windows. The method relies on a two-step approach: the first step is the computation of the exterior aero-dynamic field using an unsteady CFD solver (PowerFLOW); the second step consists in the computation of the acoustic propagation inside the cabin using a finite element vibro-acoustic solver (ACTRAN). The simplified car cabin of Hyundai Motor Company, studied in this paper, involves aluminum skin, windows, sealant, inner air cavity and acoustic treatment inside the passenger compartment (porous material, damping layer).
2015-06-15
Technical Paper
2015-01-2267
Youngha Kim, Choonhyu Kim, Jaewoong Lee, Sunggi Kim
Abstract This paper describes a structure-borne noise reduction process that was developed using a combination of experimental and analytical methods. First, the major noise paths were identified using experimental Transfer Path Analysis (TPA). Next, FEA-Experimental modeling and forced response simulation were conducted using the Hybrid FEA-Experimental FRF method. The Hybrid FEA-Experimental FRF-Based Substructuring (FBS) model was used along with Operational Deflection Shape (ODS) and Modal Analysis. The Hybrid FEA-Experimental model consisted of an experimental FRF representation of the body and a finite element model of a sub-frame. The finite element of the sub-frame was created by using Altair HyperMesh from CATIA images and the dynamic analysis was carried out by using MSC Nastran. The natural frequency and frequency response function of the finite element sub-frame model were compared with that of a real sub-frame to determine the validity of applying the Hybrid FBS method.
2015-06-15
Journal Article
2015-01-2263
Saeed J. Siavoshani, Prasad Vesikar
The intent of this paper is to document comprehensive test-based approach to analyze the door-closing event and associated sound using structural and acoustic loads developed during the event. This study looks into the door-closing phenomenon from the structural interaction point of view between the door and the body of the vehicle. The study primarily focuses on distributing the door and body interaction as discrete multiple structural and acoustic phenomena. It also emphasizes on the structural and acoustic loads developed by the discretized interactions at the interfaces between the door and the body frame. These interfaces were treated to be the load paths from the door to the body. The equivalent structural and acoustic loads were calculated indirectly using the well-known Transfer Path Analysis (TPA) methodology for structural loads and the Acoustic Source Quantification (ASQ) methodology for acoustic loads.
2015-06-15
Journal Article
2015-01-2321
Nicholas Oettle, Andrew Bissell, Sivapalan Senthooran, Mohammed Meskine
Abstract For the automotive industry, the quality and level of the wind noise contribution has a growing importance and therefore should be addressed as early as possible in the development process. Each component of the vehicle is designed to meet its individual noise target to ensure the wind noise passenger comfort level inside the vehicle is met. Sunroof broadband noise is generated by the turbulent flow developed over the roof opening. A strong shear layer and vortices impacting on the trailing edge of the sunroof are typical mechanisms related to the noise production. Sunroof designs are tested to meet broadband noise targets. Experimentally testing designs and making changes to meet these design targets typically involves high cost prototypes, expensive wind tunnel sessions and potentially late design changes.
2015-06-15
Journal Article
2015-01-2222
Nikos Zafeiropoulos, Marco Ballatore, Andy Moorhouse, Andy Mackay
Abstract Axle forces from tire-road interaction can excite different structural resonances of the vehicle hence a high number of sensors is required for observing and separating all the vibrations dynamics that are coherent with the cabin noise. Feed-forward road noise control strategies adopted so far rely mainly on capturing these dynamics and thus the number of sensors constitutes one major limitation of this approach. Therefore there is a necessity for reducing the number of sensors without degrading the performance of an ANC system. In the past coherence function analysis has been found to be a useful tool for optimizing the sensor location. In this case coherence function mapping was performed between an array of vibration sensors and the headrest microphones in order to identify the locations on the structure that are highly correlated with road noise bands in the compartment.
2015-06-15
Journal Article
2015-01-2265
Murali Balasubramanian, Ahmed Shaik
Abstract Automotive manufacturers are being challenged to come up with radical solutions to achieve substantial (30-35%) vehicle weight reductions without compromising Safety, Durability, Handling, Aero-thermal or Noise, Vibration and Harshness (NVH) performance. Developing light weight vehicle enablers have assumed foremost priority amongst vehicle engineering teams in order to address the stringent Fuel Economy Performance (FEP) targets while facilitating lower CO2 emissions, downsizing of engines, lower battery capacities etc. Body sheet metal panels have become prime targets for weight reductions via gage reduction, high strength steel replacement, lighter material applications, lightening holes etc. Many of these panel weight reduction solutions are in sharp conflict with NVH performance requirements.
2015-06-15
Technical Paper
2015-01-2264
Rama Subbu, Baskar Anthonysamy, Piyush Mani Sharma
Abstract In India, demand for motorcycle with good comfort is increasing among the customers thereby the vibration reduction of two wheelers is key parameter for motorcycle manufacturers. In order to overcome the demand in the market, manufacturers are giving more importance to cost of the product by reducing the material. This results in the reduction of the life cycle of the vehicle models and drives the manufacturers to different product design philosophies and design tools, as one would expect. One of the performance factors that continue to challenge designers is that of vehicle vertical acceleration experienced by the motorcycle components. An essential tool in the motorcycle development process is the ability to quantify the durability of the component. This paper main objective is to increase the life of the motorcycle front fender through virtual simulation, on road testing and laboratory testing using NVH tool.
2015-04-14
Technical Paper
2015-01-1700
John D. Bullough
Abstract Warning lights and beacons on service vehicles such as maintenance trucks, tow trucks, utility service vehicles and delivery vehicles are an important line of defense for the workers who operate them. These flashing lights can also contribute to visual chaos making it difficult to navigate through a work zone location. Research on the flashing configuration and spatial and temporal coordination of warning lights that could adapt to ambient conditions and situations is described, leading to recommendations for preliminary performance specifications
2015-04-14
Technical Paper
2015-01-1701
Luciano Lukacs
Abstract The challenges around global products have been lately one of the key challenges for the lighting community. This paper will present a survey which was held with costumers from China, India, Europe and Brazil understanding the difference and similarities regarding the lighting attributes. It brings also a discussion how to develop a lamp globally that fulfils everyone's needs and addresses potential trade-offs in design and performance.
2015-04-14
Technical Paper
2015-01-1703
John D. Bullough
Abstract Assessing the safety impacts of vehicle forward lighting is a challenge because crash data do not always contain details necessary to ascertain the role, if any, of lighting in crashes. The present paper describes several approaches to evaluating the safety impacts of lighting using naturalistic driving data. Driving behavioral data and descriptive narratives of crashes and near-miss incidents might provide new opportunities to understand how forward lighting improves traffic safety.
2015-04-14
Technical Paper
2015-01-0363
Vasanth Balashunmuganathan, Ramakrishna Nukala, Sathishkumar Sampath Kumar, Murali Govindarajalu
In recent years clearing the mist on side windows is one of the main criterions for all OEMs for providing comfort level to the person while driving. Visibility through the side windows will be poor when the mist is not cleared to the desired level. “Windows fog up excessively/don't clear quickly” is one of the JD Power question to assess the customer satisfaction related to HVAC performance. In a Mobile Air Conditioning System, HVAC demister duct and outlet plays an important role for removing the mist formation on vehicle side window. Normally demister duct and outlet design is evaluated by the target airflow and velocity achieved at driver and passenger side window. The methodology for optimizing the demister outlet located at side door trim has been discussed. Detailed studies are carried out for creating a parametric modeling and optimization of demister outlet design for meeting the target velocity.
2015-04-14
Technical Paper
2015-01-0564
Sung Wook Moon, Byunghyun Kang, Jaeyoung Lim, Byoung-Ho Choi
Abstract In a car accident which is involving pedestrians, head injuries occur very frequently as the head of the pedestrian hits the windshield. The head injury criterion (HIC) obtained through the windshield impact test is used to evaluate the pedestrian injury, and car manufacturers are trying to meet the criterion by changing the design and/or materials.. However, there are some difficulties in the windshield impact test, e.g. a large scatter of the test data or windshield shape-dependent property of the test. These problems make it very difficult to obtain the meaningful results from single test and thus, tests should be executed several times. In this study, a lab-scale windshield impact test was performed using a modified instrumented dart impact (IDI) tester. Tests were carried out by switching test conditions such as the impact speed, the size of the head form and the specimen thickness.
2015-04-14
Technical Paper
2015-01-0496
Anindya Deb, Ranga Srinivas Gunti, Clifford Chou, Utpal Dutta
The present work is concerned with the objective of multi disciplinary design optimization (MDO) of an automotive front end structure using truncated finite element model. A truncated finite element model of a real world vehicle is developed and its efficacy for use in design optimization is demonstrated. The main goal adopted here is minimizing the weight of the front end structure meeting NVH, durability and crash safety targets. Using the Response Surface Method (RSM) and the Design Of Experiments (DOE) technique, second order polynomial response surfaces are generated for prediction of the structural performance parameters such as lowest modal frequency, fatigue life, and peak deceleration value.
2015-04-14
Technical Paper
2015-01-1304
G Karthik, K V Balaji, Rao Venkateshwara, Bagul Rahul
Abstract This paper describes the suitability of recycled polyethylene terephthalate (RPET) material for canopy strip in a commercial vehicle. The material described in this paper is a PET compound recycled from used PET bottles and reinforced with glass fibers so as to meet the product's functional requirements. The application described in this paper is a Canopy strip which is a structural exterior plastic part. Canopy strip acts as a structural frame to hold the Vinyl canopy in both sides of the vehicle. Functionally, the part demands a material with adequate mechanical and thermal properties. Generally, PET bottles are thrown after use thereby creating land pollution. PET being inert takes an extremely long time to degrade thereby occupying huge amount of space in landfills and directly affecting rain water percolation. This work focused on recycling the PET bottles and compounding them suitably so as convert them into useful automotive parts.
2015-04-14
Technical Paper
2015-01-1312
MyoungKwon Je
Abstract The power sliding door system(PSD) is being equipped in the MPV(Multi-Purpose Vehicle/minivans) vehicle for convenience in the door operation. This study will focus on package space optimization for interior design and overall vehicle packaging for the vehicles equipped with PSD. To optimize the package, investigation for PSD's structure need to be done and the examples of other vehicle maker will be investigated and compared. The study that considers performance and package requirements resulted in a unique PSD design. And finally, this study will show the result vehicle in which the optimized mechanism is applied.
2015-04-14
Technical Paper
2015-01-1313
Donald Jasurda
Abstract The effects of thermal expansion and gravity on assembly processes in automotive manufacturing can and often do cause unexpected variation. Not only do these effects cause assembly issues, they can also create non-conformance and warranty problems later in the product lifecycle. Using 3D CAD models, advances in simulation allow engineers to design out these influences through a combination of tooling, process and tolerance changes to reduce costs. This whitepaper examines the process of simulating the effect of both thermal expansion and gravity on automotive structures. Using real life examples, a number of solutions were determined and tested in a simulated environment to reduce product variation and account for unavoidable environmental variation.
2015-04-14
Technical Paper
2015-01-1324
Guangtian Gavin Song, Chin-An Tan
Abstract Nowadays, as an irreplaceable means alongside CAD and testing, CAE is more and more widely applied with advanced material modeling and simulation methods continuously being explored, so as to get more accurate result as testing. In vehicle product development process, door slam durability evaluation is an important measurement for body closure structure. So far numerous effort has been taken to develop more mature methods to well define door slam simulation in stress and fatigue life analysis. Overall all methods ever being applied can be summarized as two categories, linear stress based method and nonlinear stress based method. The methodologies, such as inertia relief method, direct transient response solution, or local strain approach, can be included in linear stress based method with linear material properties as symbol in CAE model. In local strain approach, contact surface could be defined in the necessary area with consideration for more realistic load transfer.
2015-04-14
Technical Paper
2015-01-1128
Amrut A. Patki
Abstract Several critical factors influence the conventional practice of defining driveline propeller shafts. One of these is the location of the center bearing bracket mounting. This in-turn depends on the frame ladder's crossmember. It has been observed that this dependence results in more number of joints and propeller shafts. “Driveline optimization by mini crossmember” is one of the solutions that offers flexibility in regards to the location of the center bearing bracket. Also this helps in achieving optimization.
2015-04-14
Technical Paper
2015-01-1340
Yoichi Toyooka, Kiyoshi Hasegawa
Abstract Automotive outer panels may be distorted during heat treatments for curing of structural adhesives and mastic sealers. Distortion occurs due to residual stress between the adhesive and the panel following the curing process of the adhesive. The research discussed in this paper therefore considered a simulation technique of distortion and measuring method using curvature as the evaluative indicator. Curvature refers to the change of gradient of the curved surface, and the difference in curvature between the standard shape of the panel and the distortion section closely resembles the results of visual evaluations. Test panels were manufactured and measurements of their curvature were conducted. A study of the correlation of measurement results with the results of visual evaluations showed a good match.
2015-04-14
Technical Paper
2015-01-0526
Timo Faath, Lay Knoerr
Abstract In the new ThyssenKrupp InCar®plus project, numerous solutions were developed for vehicle components and systems that contribute to increased efficiency through the use of new materials and advanced manufacturing technologies. These solutions are superior to current production applications in terms of weight, cost, performance and sustainability, while also meeting the demand for cost-effective weight reduction. This paper features structural components solutions focusing on Bumpers, and A- and B-pillars which overall attained between 8% to 19% weight reduction compared to their significant reference parts by incorporating flexible design concepts, progressive new materials, virtual analyses, and innovative manufacturing processes that have been tested and validated along the entire value chain. The prototypes developed were subjected to stringent safety assessments.
2015-04-14
Technical Paper
2015-01-1370
Mehran Ebrahimi, Kamran Behdinan
Abstract Nowadays, moving toward more lightweight designs is the key goal of all major automotive industries, and they are always looking for more mass saving replacements. In this study, a new methodology for the design and optimization of cross-car beam (CCB) assemblies is proposed to obtain a more lightweight aluminum design as a substitution for the steel counterpart considering targeted performances. For this purpose, first, topology optimization on a solid aluminum geometry encompassing the entire design space should be carried out to obtain the element density distribution within the model. Reinforcing locations with high element density and eliminating those with density lower than the threshold value result in the conceptual design of the CCB. To attain the final conceptual design, the process of topology optimization and removal of unnecessary elements should be addressed in several steps.
2015-04-14
Technical Paper
2015-01-0580
Fei Lei, Xin Chen, Xiao Ping Xie, Jing Zhu
Abstract Lightweight automotive body can be obtained by developing new body constructions, using lightweight materials and structural optimizations, etc. Usually, lighter materials and structural optimizations are main aspects considered in lightweight automotive body engineering. In fact, material costs and manufacturability play more important roles than others in lightweight design. Three lightweight design approaches are considered. The first approach of lightweight design is to replace steels with lighter materials using equal rigidity design method. The second approach is a single objective optimization of mass reduction with materials selection and cost penalty. The third approach is a multi-objective optimization of mass reduction and cost reduction using multi-material concept. These three approaches are applied to an automotive body design problem considering the side impact. Different optimization methods are used to obtain different results.
2015-04-14
Technical Paper
2015-01-0532
Mingchao Guo, Weidong Zhang, Dajun Zhang, Ram Bhandarkar
Abstract This paper describes a CAE fatigue life prediction technique for a tailgate on pickup truck cargo box with inertial forces and moments applied at mass center of the tailgate as input loads. The inertial forces and moments are calculated from the accelerations measured at the corners of the tailgate as the truck is being driven over a durability schedule at the test proving grounds. All the dynamic responses of the tailgate on cargo box, including any dynamic interactions at the pivot joints between the tailgate and box sides, are captured in the acquired data and also in the inertial forces and moments computed at the mass center. Correspondingly, all the dynamic responses are included in the CAE fatigue life predictions. The dynamic interactions at the pivot joints are simulated by using two identical CAE models, one with lateral translational constraint applied at the left pivot only and the other at the right pivot only.
2015-04-14
Technical Paper
2015-01-0640
Song Huang, Jianpeng Shi, Chaoliang Shi
Abstract A design method is applied for protection load bearing body. Firstly the finite element model of the vehicle body is established. Using the topology optimization technique, the structure of the vehicle body is optimized. In details the first order modal and the stiffness of the body are both improved. Meanwhile the lightweight design of the vehicle is realized in the optimization. Based on the optimal vehicle body, the loads at the connection points of the vehicle body and chassis are obtained using the multi-body dynamics simulation technique. Making use of the loads at the connection points and the FE model, the strength of the vehicle body is analyzed. It proves that the strength of the optimal vehicle meets the requirements. This design method can be also applied for other types of vehicle bodies even other vehicle components.
2015-04-14
Technical Paper
2015-01-0360
Maryline Leriche, Wolfgang Roessner, Heinrich Reister, Bernhard Weigand
Abstract An accurate model to predict the formation of fogging and defogging which occurs for low windshield temperatures is helpful for designing the air-conditioning system in a car. Using a multiphase flow approach and additional user-defined functions within the commercial CFD-software STAR-CCM+, a model which is able to calculate the amount of water droplets on the windshield from condensation and which causes the fogging is set up. Different parameters like relative humidity, air temperature, mass flow rate and droplet distributions are considered. Because of the condition of the windshield's surface, the condensation occurs as tiny droplets with different sizes. The distribution of these very small droplets must be obtained to estimate numerically the heat transfer coefficient during the condensation process to predict the defogging time.
Viewing 241 to 270 of 4645