Browse Topic: Fenders
The rising importance of sustainability in the automotive sector has led to increased interest in circular and environmentally responsible materials, particularly for plastic trims parts, both interior and exterior. This study focuses on developing textile solutions using recycled polyethylene terephthalate (r-PET) sourced from post-consumer plastic waste, along with bio-based fibres such as bamboo. These materials made into woven and knitted fabrics are studied to suit different vehicle interior applications. r-PET textiles show promising strength, aesthetic appeal, and durability performance. Bamboo fabrics are known for their natural antimicrobial properties and enhanced breathability. Extensive testing is performed to validate explored sustainable materials performance against key automotive requirements. With this study, we gain an understanding of the performance of variedly sourced sustainable raw materials for automotive specific textile applications by different manufacturing methods.
In the past few decades, the automotive industry saw the development of several environment-friendly technologies, as high efficiency engines, lightweight materials, and low-rolling-resistance tires. Car body styling, together with aerodynamics, play an important role in resolving environmental issues by reducing drag force, which results in high fuel efficiency and lower energy requirements. The main objective of this study is the reduction of the aerodynamic resistance of a city-car prototype by means of flow control devices (air blow and air relief) located into the wheel arches. This work starts from the wind tunnel experimental tests of the baseline version of the XAM 2.0 vehicle, then, dedicated ducts are implemented into the model in order to reduce the turbulence of the front wheel well and the air-flow defection at the end of the sides of the car body. A CFD analysis is carried out in order to assess the effects of the introduced modifications: car shape is varied by CAS, for every modification CFD calculations are performed. A correlation between wind tunnel and CFD results is carried out validating the drag optimization, demonstrating the predictive capabilities of CFD analysis and a record-breaking drag coefficient.
In industries, the usage of natural fibre composites (NFC) becomes one of the inevitable materials in the engineering field. The applications are owing to its characteristics like high strength to weight ratio, recyclability less density and inexpensive. In recent days the automotive parts like door trim panels, wheel arch, rear hatch, roof liner and bonnet insulation were replaced using NFC. Present-day huge usage of NFC people is working on the recyclability of composites. The present research aimed to recycle the NFC waste as reinforcement in the sisal/epoxy composite. The effect of composite waste reinforcement at various weight percentages (0, 5, 10 and 15%) were studied. The sisal/epoxy composite subjected to mechanical characterisations and drilling performance were studied by varying the process parameters such as feed and spindle speed using design of experiment (DOE). The distribution of the reinforcement and the bonding between the fiber and matrix were examined through a scanning electron microscope (SEM). The addition of composite waste (5%-300μ) improves the mechanical and machining properties of the composite.
In the modern automobile scenario in developing countries, customers are getting more meticulous and market more competitive. Now even the budget vehicle customer expects desirable vehicle performance in specific use cases of the vehicle that were previously not focused by designers. Hence, the focus on perceived quality challenges automobile engineers to go the extra mile when it comes to the cost-effective design of parts that are tangible to the customer. A vehicle's cowl cover is one such exterior component. The primary functions of this part are to provide air intake opening for the HVAC system and cover the components like wiper motor. The aesthetic function is to cover the gaps between windshield, hood, and fender as seamlessly as possible. A specific role of cowl cover, which calls for a designer's attention, is its load-bearing capability. This component has to be stiff enough to bear external loads like snow accumulation or application of hand on the part by customer or service personnel. Simultaneously, it plays a significant role in absorbing the energy of a pedestrian's head impact during a crash. This engenders a need to optimize the cowl cover design for energy absorption in one direction and deformation resistance in another direction. This paper explains the methodology in which a cowl cover can be designed to cater to the need for directional load bearing without adversely affecting the pedestrian impact performance of the part. With the help of FEA, cost-effective design approaches for improving the stiffness of cowl cover assembly are studied, and their effect on pedestrian energy absorption is checked. Finally, the study identifies and discusses the concepts which have favorable stiffness with a limited impact on pedestrian energy absorption.
In this paper, mold in color diamond white ASA material has been explored for front bumper grill, fender arch extension, claddings and hinge cover applications. Other than aesthetic requirements, these parts have precise fitment requirement under sun load condition in real world usage profile. Structural durability of the design was validated by virtual engineering. Part design and material combinations with better tooling design iterations were analyzed by using mold flow analysis. Complete product performances were validated for predefined key test metrics such as structural durability, thermal aging, cold impact, scratch resistance, and weathering criteria. This part met required specification. This mold in color ASA material-based parts has various benefits such as environmentally friendly manufacturing by eliminating environmental issues of coating, easily recycled, and faster part production because intended color achieved in one step during molding. Also, it lowers overall production energy footprint, less scrap with no secondary painting, and lower final part cost by eliminating secondary operations.
While riding cycles, cyclists usually experience an aerodynamic drag force. Over the years, there has been a global effort to reduce the aerodynamic drag of a cycle. Fenders affect the aerodynamic drag of a cycle to a large extent, and fender coverage has a pronounced effect on the same. In this article, various fender coverage angles, varying from 60° to 270°, were studied to predict the aerodynamic drag with the help of a validated CFD model in SolidWorks Flow Simulation. The model was based on the Favre-Averaged Navier-Stokes (FANS) equations solved using the k-ɛ model. It was predicted that aerodynamic drag coefficient reduced fender coverage angle up to 135°, and thereafter started increasing. Analyses were carried out at velocities of 6 m/s, 8 m/s and 10 m/s and the results were found to be similar, with a minimum aerodynamic drag coefficient at 135° occurring in all the cases under study. There was an observed optimum decrease in drag coefficient to the extent of 4.6%, 4.5% and 4.6% as compared to the bicycle without fenders for the 6 m/s, 8 m/s and 10 m/s cases, respectively.
Eleven instrumented crash tests were performed as part of the 2016 World Reconstruction Exposition (WREX2016), using seven Harley-Davidson motorcycles and three automobiles. For all tests, the automobile was stationary while the motorcycle was delivered into the vehicle, while upright with tires rolling, at varying speeds. Seven tests were performed at speeds between 30 and 46 mph while four low-speed tests were performed to establish the onset of permanent motorcycle deformation. Data from these tests, and other published testing, was analyzed using previously published equations to determine their accuracy when predicting the impact speed of Harley-Davidson motorcycles. The most accurate model was the Modified Eubanks set of equations introduced in 2009, producing errors with an average of 0.4 mph and a standard deviation (SD) of 4.8 mph. An updated set of Eubanks-style equations were developed adding data published since 2009, and further partitioning from two equations (pillars/axles and doors/fenders) to four equations (axles, pillars/bumpers, doors, and fenders). When applied to the subject tests, the newly developed set of equations produced an average error of 3.5 mph (SD = 4.3 mph). With respect to all available data (N = 99), the equations produced an average error of 0.1 mph and an SD of 5.8 mph. The errors were also analyzed for each of the four equations developed here, and confidence intervals offered. This research, which represents the first detailed analysis of Harley-Davidson motorcycles’ collision response, indicates they behave in a manner similar to previously tested motorcycles. Further, the equations developed and presented here give accident investigators a refined method for estimating the impact speed of an upright motorcycle, Harley-Davidson or otherwise, having struck an automobile with its front tire.
Eleven instrumented crash tests were performed as part of the 2016 World Reconstruction Exposition (WREX2016), using seven Harley-Davidson motorcycles and three automobiles. For all tests, the automobile was stationary while the motorcycle was delivered into the vehicle, while upright with tires rolling, at varying speeds. Seven tests were performed at speeds between 30 and 46 mph while four low-speed tests were performed to establish the onset of permanent motorcycle deformation. Data from these tests, and other published testing, was analyzed using available models to determine their accuracy when predicting the impact speed of Harley-Davidson motorcycles. The most accurate model was the Modified Eubanks set of equations introduced in 2009, producing errors with an average of 0.4 mph and a standard deviation (SD) of 4.8 mph. An updated set of Eubanks-style equations were developed adding data published since 2009, and advancing from two equations (pillars/axles and doors/fenders) to four equations (axles, pillars/bumpers, doors, and fenders). When applied to the subject tests, the newly developed set of equations produced an average error of 3.5 mph (SD = 4.3 mph). With respect to all available data (N = 99), the equations produced an average error of 0.1 mph and a standard deviation of 5.8 mph. The errors were also analyzed for each of the four equations developed here, and confidence intervals offered. This research, which represents the first detailed analysis of Harley-Davidson motorcycles’ collision response, indicates they behave in a manner similar to previously tested motorcycles. Further, the equations developed and presented here give accident investigators a refined method for estimating the impact speed of an upright motorcycle, Harley-Davidson or otherwise, having struck an automobile with its front tire.
Although its best-ever sales year was barely more than 50,000 units and many critics questioned the buying public's desire for a midsize pickup based on a unibody structure instead of the tried-and-true body-on-chassis layout, Honda remained faithful to the concept it introduced with the first-generation Ridgeline pickup, producing it for ten years from 2005-2014. Even through the recession and auto-industry downturn, Honda insisted it was keen to develop a second-generation Ridgeline, to continue to press the idea that if many in pickup-crazed America took an honest look at what they want from a pickup-and equally important, how they actually use a pickup-a unibody-based design would be the most satisfying choice.
A wall-resolving Large Eddy Simulation (LES) has been performed by using up to 40 billion grids with a minimum grid resolution of 0.1 mm for predicting the exterior hydrodynamic pressure fluctuations in the turbulent boundary layers of a test car with simplified geometry. At several sampling points on the car surface, which included a point on the side window, the door panel, and the front fender panel, the computed hydrodynamic pressure fluctuations were compared with those measured by microphones installed on the surface of the car in a wind tunnel, and effects of the grid resolution on the accuracy of the predicted frequency spectra were discussed. The power spectra of the pressure fluctuations computed with 5 billion grid LES agreed reasonably well with those measured in the wind tunnel up to around 2 kHz although they had some discrepancy with the measured ones in the low and middle frequencies. The Dynamic Smagorinsky Model (DSM) was adopted for the subgrid-scale turbulence model of LES while the resulting spatially-filtered Navier-Stokes equations of the incompressible fluid flow were solved by a Finite Element Method. In the second paper of this series of studies, the hydrodynamic pressure fluctuations computed on the car surfaces will be used as the unsteady loading for computing the panel vibration of the test car by using Finite Element Method, and finally the interior acoustical fields will be predicted by solving the Helmholtz equation for sound propagation. The contribution from the external acoustical field to the interior noise, which was not simulated by the present incompressible LES-based approach, was estimated based on the acoustic analogy, and was confirmed to be negligibly small compared with those from the hydrodynamic loading in the present case.
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. Vibration and strain level on the front fender was measured on torture track. Accelerometers are mounted on the vehicle to extract the dynamic accelerations on the motorcycle at various connections points like front and rear axle, front steering pivot, rear cushion top pivot fender and rider foot rest during the process. On the other hand, a similar condition is simulated by using simulation using MSC.ADAMS. Finally, a qualitative comparison is made between the results of simulations and experiments. Then conversion of track time domain data into NVH data and then performing laboratory testing to find out the life of the component. The results show that both natural frequencies of the transfer path are observed same in the experiments as well as simulations.
Automotive OEM's are looking to develop plastic parts with maximum life and durability through virtual simulations with help of CAE tools, thereby saving the mold cost, material cost and time. The design constrains would be manufacturability, loads, boundary condition and aesthetics. This work involves the multi-discipline approach to virtually visualize the effect of fluid structure interaction due to splashing on the rear fender of a motorcycle which acts as mud guard. This study shows effect of splashing of water over rear fender on wet roads. First, the pressure developed on the rear fender due to impingement of water on surface is obtained through a multiphase volume of fluid analysis using CFD software Fluent. Secondly, these pressure values are taken as input in Abaqus software and the part is analyzed for its durability. The main focus was to check the change in pressure value and stress levels in rear fender by varying the following parameters; level of water, splash angle and tire width while splashing. The hot spot locations and change in behavior of rear fender due to change in parameters were taken in account for optimization of the current design and would be considered as design constrains in future.
We present an efficient numerical method to simulate the spray painting process in the automotive industry. A framework has been developed based on coupled solvers for the air flow, electromagnetic fields and paint droplets. The applied discretization method allows treating moving boundaries in an efficient way and significantly reduces preprocessing time. Thus the simulation of the painting of a car fender or a truck cab takes only a few hours on a standard computer and gives very good agreement with thickness measurements. These results demonstrate the validity of the method and its applicability to increase product quality and reduce production costs in automotive paint shops. It allows performing systematic analysis of the influence of process conditions on the paint thickness and overspray.
Transport Canada, through its ecoTECHNOLOGY for Vehicles program, retained the services of the National Research Council Canada to undertake a test program to examine the operational and human factors considerations concerning the removal of the side mirrors on a Class 8 tractor equipped with a 53 foot dry van semi-trailer. Full scale aerodynamic testing was performed in a 2 m by 3 m wind tunnel on a system component basis to quantify the possible fuel savings associated with the removal of the side mirrors. The mirrors on a Volvo VN780 tractor were removed and replaced with a prototype camera-based indirect vision system consisting of four cameras mounted in the front fender location; two cameras on either side of the vehicle. Four monitors mounted in the vehicle - two mounted on the right A-pillar and two mounted on the left A-pillar - provided indirect vision information to the vehicle operator. Four commercial drivers were asked to perform a series of tests simulating typical driving scenarios on a closed course test track. The tests included an object identification test, a blind spot comparison test, a coupling and uncoupling test, a quasi-static lane change test, a dynamic lane change test and an evasive manoeuvres test. The tests were performed both with the mirrors and with the camera-based indirect vision system. The results of the study provide an analysis of driver performance while using the mirrors in comparison to driver performance while using the camera-based indirect vision system. Driver acceptance of the camera-based indirect vision system was also analyzed through the use of questionnaires.
As one of the most important auto-body moving parts, door hinge is the key point of door design and its accessories arrangement, also the premise of the door kinematic analysis. We proposed an effective layout procedure for door hinge and developed an intelligent system on CATIA CAA platform to execute it. One toolbar and five function modules are constructed - Axis Arrangement, Section, Parting Line, Kinematic, Hinge Database. This system integrated geometrical algorithms, automatically calculate the minimum clearances between doors, fender and hinges on sections to judge if the layout is feasible. As the sizes of the clearances are set to 0s, the feasible layout regions and extreme start/end points are shown in parts window, which help the engineer to check the parting line and design a new one. Our system successfully implemented the functions of five modules for the layout of door hinge axis and parting line based on a door hinge database. An instance is carried out and the result shows that our system has great feasibility and validity to arrange the door hinge and shorten the design periods.
Stiffer-bodied sports car gains wind-aided performance with supercharging and downforce for faster lap times. Incredibly, General Motors engineers have continued to wring still more performance from a Chevrolet Corvette design package that remains very consistent, with an overhead-valve V8 engine powering the rear wheels in a vehicle that mounts a composite body atop a discrete frame. As with the previous Corvette Z06, the 2015 version employs an aluminum frame. However, now it is the same production aluminum frame built in-house as is used in the Stingray, rather than a purpose-built variation.
Thermoplastic polyester elastomer (TPEE) possesses the properties of both rubber and engineering plastic. The most important feature of this material lies in its ability to combine the superior repulsion elasticity and flexibility of rubber with the rigidity of engineering plastic. This enables it to exhibit durability against fatigue, even when exposed repeatedly to large deformation. The most remarkable feature of TPEE is such that it can realize material properties with very small strain rate dependency. The authors have had their ample experiences with applying TPEE to large damper members in the civil engineering structures, such as fenders surrounding the piers of bridges to absorb the impact energy caused by ship collisions and the aseismatic connectors built in bridge structures. This paper attempts to develop shock absorbing components of small sizes with light weight for automobile applications. Locating TPEE shock absorbers inside the crash box (members connecting the bumper system to the main body) may be thought as a typical application of the TPEE products. In order to achieve weight saving of the shock absorbing components, it is effective to utilize the buckling behaviors of thin walled structures. With regard to the buckling simulations of cylindrical shell structures, the authors have been working to develop analysis procedures for obtaining stable solutions utilizing the latest general-purpose finite element technology. This report shows that the experimental results could successfully be reproduced by applying the simulation technique to the honeycomb-shaped shock absorbing components. For realizing a desirable load-displacement relationship, this report also shows how to modify the shape of the components.
This paper investigates the crashworthiness of structural composite components in frontal and side crash tests. In addition, the safety benefits of composites applications in future lighter vehicles are studied. The methodology of the research includes two steps: (1) developing a light-weight vehicle based on a current finite element (FE) vehicle using advanced plastics and composites, and (2) evaluating the crashworthiness of the light-weighted vehicle by frontal and side New Car Assessment Program (NCAP) test simulations. An FE model of a 2007 Chevrolet Silverado, which is a body-on-frame pickup truck, was selected as the baseline vehicle for light-weighting. By light-weighting components in the Silverado, the vehicle weight was reduced 19%. As a result, the content of plastics and composite in the light-weighted vehicle was 23.6% of the total weight of the light-weight vehicle. Light-weighted composite structural components include bumpers, front-end module, fenders, pillar reinforcements, door beams, and ladder frame. Frontal and side NCAP test simulations of the light-weighted vehicle show that the light-weighted vehicles using advanced plastics and composites provide equivalent structural performance to the baseline vehicle in the full-scale impact condition. Also, this study demonstrates that using plastics and composites can reduce the vehicle weight efficiently.
Global warming and climate change are among the top subjects of growing global concern. According to International Energy Agency (IEA), about 19% of the greenhouse gas emissions from fuel combustion are generated by the transportation sector, and its share is likely to grow. A forecast by US Census Bureau predicts that there will be 3.5 billion cars by 2050 for a population of 9 billion. In this context, numbers in the industrialized world are expected to double from around half a billion to over one billion. An increase in fleet volume will have a direct and major impact on increase of CO₂ emissions. Therefore, reducing vehicle fuel consumption is one of the most critical steps for reducing greenhouse gas emissions, and reduction of vehicle weight is one of the best solutions for improving fuel efficiency. This paper attempts to emphasize the greenhouse gas and fossil fuel savings realized from light-weighting cars using online paintable Noryl* GTX* resin in fender applications instead of conventional steel fenders. SABIC Innovative Plastics (SABIC IP) conducted a detailed Cradle-to-Cradle life cycle study of an automotive fender constructed using SABIC IP's engineering thermoplastic Noryl* GTX* resin as compared with a steel-based fender. The LCA results show that the use phase is dominant and the fender made with Noryl* GTX* resin results in up to 47% lower carbon footprint and up to 45% less primary/cumulative energy demand than for the steel fender.
External components of an automotive body are manufactured from a stamping of sheet metal plane resulting in a final product with variable thickness due to different levels of stretch and a heterogeneous distribution of residual plastic strain. Generally, these informations are not considered in numerical simulations of the product and may cause considerable errors in the analysis of stamped parts involving nonlinearities. This work aimed to simulate an event called palm-printing in an automobile fender, with and without the consideration of the final data of the numerical simulation of the stamping process (final thickness and residual plastic strain) and the results compared with those obtained experimentally. Results showed that the consideration of thickness and hardening from the stamping process can improve the correlation of final results in quasi-static nonlinear analysis. However, the results showed that the influence of the thickness reduction is so important as the hardening, especially in the correlation of the reaction force of the indenter, contrary to reports in the literature in cases of crash test simulation.
To help drivers monitor the road and to reduce blind spots, Camera/Video Imaging Systems (C/VISs) display live video from cameras mounted on the truck's exterior to drivers using displays inside the truck cabin. This study investigated drivers' performance with C/VISs in a real-world trucking operation. Twelve commercial drivers' performance with and without a C/VIS was continuously recorded while they each drove for four months. Half of the drivers used a commercially available C/VIS that had a side-view camera on each fender. The other drivers used an advanced C/VIS (A-C/VIS) that had side-view cameras, a rear-view camera, and night-vision capabilities. This paper presents the study's final results and expands on the preliminary results that were previously reported. Detailed analyses of drivers' involvement in Safety-Critical Events (SCEs), their lane change performance, and their opinions of the C/VISs are presented. Overall, it was found that when a C/VIS was provided: 1) drivers' involvement in safety-critical events (SCEs) did not change, 2) the probability that drivers looked forward did not change, 3) the clearance to an adjacent vehicle when changing lanes did not change, 4) drivers were more likely to use the C/VIS at night and when making right lane changes, and 5) drivers indicated that the C/VISs helped them become aware of surrounding objects and merge into traffic. In terms of disbenefits, some drivers indicated that glare from the commercially available C/VIS monitors, as positioned to specifications, could be uncomfortable at night. The A-C/VIS's advanced features were highly rated by drivers. The rear-view camera was also used more than the left or right fender cameras. In summary, it was found that C/VISs are able to assist CMV drivers in their daily driving task without deteriorating their driving performance.
This paper explains the specific measures taken to develop the body and underfloor of the newly developed Electric Vehicle for the purpose of reducing drag. Additionally, the headlamps and fenders were designed with innovative shapes to reduce wind noise that occurs near the outside mirrors. As a result of utilizing the aerodynamic advantages of an electric vehicle to maximum effect, The newly developed Electric Vehicle achieves a class-leading drag coefficient and interior quietness.
For guidance only in regard to highway commercial motor vehicles where protection to the rear against rear wheel splash and stone throw is deemed necessary, the following clearance specifications are recommended.
Automotive fenders is one such example where specialized thermoplastic material Noryl GTX* (blend of Polyphenyleneoxide (PPO) + Polyamide (PA)) has successfully replaced metal by meeting functional requirements. The evolution of a fender design to fulfill these requirements is often obtained through a combination of unique material properties and predictive engineering backed design process that accounts for fender behavior during the various phases of its lifecycle. This paper gives an overview of the collaborative design process between Mitsubishi Motors Corporation and SABIC Innovative Plastics and the role of predictive engineering in the evolution of a thermoplastic fender design of Mitsubishi Motors Corporation's compact SUV RVR fender launched recently. While significant predictive work was done on manufacturing and use stage design aspects, the focus of this paper is the design work related to identifying support configuration during the paint bake cycle. In this paper, simulation results of several real life design changes that were evaluated for their efficacy in reducing deformation during paint bake are presented followed by qualitative comparison between experimental and simulation data.
The purpose of the study was to identify all small overlap impacts using published coded NASS-CDS data. Three sets of criteria were used: CDC measurements; crush profiles for frontal impacts; and crush profiles for oblique side impacts to the fender component. All criteria were applied to passenger and non-passenger cars and their different vehicle class sizes. Data were analyzed based on fatalities and different levels of MAIS trauma. The overall data set based on CDC codes for 2005 to 2008 NASS-CDS data had 9,206 MAIS=0; 13,522 MAIS=1-2; 3,600 MAIS=3-6; 1,092 MAIS=7; and 961 fatal cases. For the weighted ensemble, these data were: 5,800,295; 4,324,773; 269,042; 219,481; and 44,906 cases, respectively. However, these cases reduced to 1071, 1468, 364, 82, and 87 raw cases with the application of the CDC criteria for frontal impacts. Comparing the CDC criterion to the crush profile for front and side impact criteria, an increase of approximately 44% raw and 40% weighted fatal cases, and 49% raw and 52% weighted MAIS 3-6 cases were found in the ensemble. The operational definition encompassing CDC and crush profiles for front and side impacts provided a more comprehensive assessment of small overlap impacts, hitherto not reported in literature. Using this larger ensemble, it is possible to conduct further analyses of injuries and other crashworthiness-related parameters. In addition, this operational definition can be applied to all databases with CDC codes to classify impacts and crush profiles.
This paper is motivated by the need to predict deformation behavior of an automotive thermoplastic fender during its residence in e-coat paint bake oven where it is heated by convective currents from blowers. Part - 1 [ 1 ] of this paper, presented a FEA methodology to model the behavior of thermoplastic fender during ecoat bake. Additionally a multiphysics computational procedure to include effect of temperature and stress history was also proposed to enhance the accuracy of the solution. In this paper, we focus on the prediction of temperature history and its influence on fender deformation. Towards this, we present a two-stage thermo-mechanical simulation procedure utilizing CFD and FEA to model the ecoat bake process. While the procedure can model the heating of the fender by convective currents from blowers using CFD, the required flow field data of the ecoat oven is highly confidential. Hence, we also study the influence of approximating the temperature field on displacement prediction. To study the influence of approximating the temperature field on displacement prediction we considered three different temperature inputs to the stress analysis. In the first case, we employed results of the transient thermal simulation as input. For the second case, we used temperature profile obtained from thermocouple measurement and for the third most simplified case; we assumed a linearized profile, which captures the peak temperature and the correct residence time. We had run this simulation on two distinct real life fender geometries. The comparative simulation data indicates that the approximation of the temperature has lesser effect on the fender with uniform thickness as compared to a fender with thickness variation and relatively higher mass. Thus, the two-stage procedure proposed in this paper can be simplified in the initial design phase. However, for production level parts that typically have thickness variation, the comprehensive approach utilizing CFD and FEA is recommended.
As the pedestrian impact regulations are continuing to evolve, there is a growing emphasis on each and every component of a vehicle front to be pedestrian friendly. Traditionally pedestrian safety during an automotive impact is ensured through bumper, grill, fender and hood. However, the headlamp design was not under the same level of consideration as compared to other frontal components. To make pedestrian safety complete, the headlamp also needs to adhere to the pedestrian safety regulations. A novel energy absorber ring (EAR) concept was developed to make the headlamps pedestrian friendly. The proposed EAR concept was found to improve the pedestrian safety and low speed vehicle damageability performance. It was also observed that the proposed concept reduces the replacement and insurance cost.
Recent estimates of the annual cost to repair vehicle damage from motor vehicle crashes ranges from $17 billion (£9.1 billion) paid by U.K insurers to $45 billion paid by U.S. insurers. Many of these repairs were for damage sustained in low-speed front and rear impacts, with the majority costing less than $2, 500 to repair in both countries. In about a quarter of all claims the damage is limited to the vehicle corners and vehicle bumpers should prevent or limit much of the damage sustained in these minor crashes. However, many vehicles do not have bumper reinforcement beams that extend laterally much beyond the frame rails, leaving expensive vehicle components such as headlamps and fenders (wings) unprotected. Research by IIHS and Thatcham shows that 15 percent overlap front and rear crash tests at 5 km/h into a bumper-shaped barrier produce vehicle damage similar to that seen in real-world crashes and in vehicle-to-vehicle front-to-rear crash tests with low overlap. Tests also show that relatively minor modifications to bumper beams can greatly reduce the extent of this damage in low-speed collisions.
Two wheelers are becoming increasingly popular in India. Competition in this segment has made the product developers to develop the vehicles with short time without compromising durability. Vibration Fatigue Analysis is an advanced technique to evaluate the life of components undergoing vibration, thereby the drastic reduction in durability evaluation time. Front fender is a styling component generally made with plastic material and undergoes vibrations. Therefore, it is very difficult to design the fender based only on static load cases. Vibration fatigue analysis using Finite Element Method (FEM) is used to ensure the durability in design stage itself. Various customer usage modes of the vehicle are considered. Accelerometers and strain gauges are mounted on the fender on appropriate locations. First, the instrumented fender is mounted on the electro dynamic shaker. The fender is excited with sinusoidal inputs. FE Model is made using shell elements and harmonic response analysis is done with the same inputs as in shaker. FE based stress response result is validated with the measured responses. Using the predicted stress responses fatigue life offender is calculated. Then the fender is assembled with the vehicle and the vehicle is driven in customer usage modes. Acceleration, frequency and strain data are measured for each of these modes. The measured data are used for arriving at test standard also. The FE estimated life is compared with the target life and based on the comparison the design is cleared for mass production.
General Motor's Corvette product engineering was given the challenge to find mass reduction opportunities on the painted body panels of the C6 Z06 through the utilization of carbon fiber reinforced composites (CFRC). The successful implementation of a carbon fiber hood on the 2004 C5 Commemorative Edition Z06 Corvette was the springboard for Corvette Team's appetite for a more extensive application of CFRC on the C6 Z06 model. Fenders were identified as the best application for the technology given their location on the front of the vehicle and the amount of mass saved. The C6 Z06 CFRC fenders provide 6kg reduction of vehicle mass as compared to the smaller RRIM fenders used on the Coupe and Convertible models. The strength, stiffness and manufacturing flexibility of the CFRF technology allowed for the elimination or simplification of several components required on the Coupe and Convertible style fenders, further reducing required tooling investment, mass and build complexity for the Z06 model. FEA analysis was used to ensure that all structural requirements were achieved. Extensive study was given to the selection of the specific carbon fiber epoxy pre-preg material to be utilized for the production. The material selection study investigated several factors that optimize the balance between material cost, conformability, labor time, finishing, and ability to achieve a high quality painted surface finish that is operationally transparent to the General Motor's Bowling Green Assembly paint process. The result is the highest yearly volume of carbon fiber content in the automotive industry whether measured by vehicles/year or pounds material used/year.
In 1996, the European Enhanced Vehicle Safety Committee, Working Group 17 (EEVC WG17) proposed a set of impact procedures to evaluate the pedestrian injury risk of vehicle fronts. These procedures address three aspects of pedestrian protection – head impacts, lower limb impacts, and thigh impacts – through vehicle subsystem tests. The criteria assessed during these impact tests are affected by the design of most parts of the vehicle body front-end. One of the challenges to vehicle design introduced by these tests is the impact of an adult pedestrian headform to the top of the fender. The proposed acceptance level for Head Injury Criterion (HIC) is less than 1000 during impacts at 40 km/h. This paper uses the finite element (FE) method to predict the influence of proposed fender and shotgun design modifications aimed at meeting this target. In addition, the known issues with the implementation of these proposed changes are discussed. Although the proposed changes are shown to meet the target in the theoretical analyses presented in this paper, these changes are also demonstrated to conflict with other aspects of vehicle safety (frontal visibility and frontal high-speed impact), vehicle manufacturing, and durability.
For guidance only in regard to highway commercial motor vehicles where protection to the rear against rear wheel splash and stone throw is deemed necessary, the following clearance specifications are recommended.
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