Refine Your Search

Topic

Author

Affiliation

Search Results

Technical Paper

The Behavior of Fuel Droplets on a Heated Substrate

2021-10-15
2021-01-5099
The processes of surface wetting and film evaporation play a major role in any application using liquid fuels. Since the behavior of entire multi-liquid films is influenced by many simultaneously occurring physical processes, exact modeling is not yet possible. In order to reduce the complexity and to determine the basic effects in the spreading and evaporation of multi-component films, this study was carried out by placing single 5 μl droplets on a heated metal surface. Various alkanes, ethanol, and mixtures, as well as real gasoline, were studied at surface temperatures between 69°C and 140°C. To describe the processes qualitatively and determine the time-dependent wetted surface area, the droplets were visualized using cameras. With the results, it was possible to determine the course of the wetted surface over time and to compare different liquids under varying surface temperatures.
Technical Paper

Lining Property Characterizations for an Improved Integration Cascade

2021-10-11
2021-01-1272
New technologies, such as electrified powertrain and autonomous driving solutions, are transforming the automotive industry in such a way that achieving vehicle level performance requirements demands an increasingly intensive and detailed system integration exercise. Validation of the braking system, critical to any vehicle level project, must evolve so that the ever-increasing requirements cascade is answered in a way that ensures the highest level of safety and performance as the industry moves toward a new frontier of features. To support this evolution of integration methodology, critical-to-performance components, such as brake pads, must undergo a transformation in how performance metrics are characterized, communicated, and documented.
Technical Paper

Research on High-efficiency Test Method of Vehicle AEB based on High-precision Detection of Radar Turntable Encoder

2021-10-11
2021-01-1273
With the increasingly complex traffic environment, the vehicle AEB system needs to go through a large number of testing processes, in order to drive more safely on the road. For speeding up the development process of AEB and solve the problems of long cycle, high cost and low efficiency in AEB testing, in this paper, a millimeter wave radar turntable is built, and a high-precision detection algorithm of turntable encoder is designed, at the same time, a test method of vehicle AEB based on the detection data of radar turntable encoder is designed. The verification results show that methods described in this paper can be used to develop the vehicle AEB test algorithm efficiently.
Technical Paper

Thermomechanical Instabilities in Metal-Free Friction Materials Using a Nonlinear Transient Simulation Approach

2021-10-11
2021-01-1286
The invention of metal-free friction materials is gaining popularity in the manufacturing of brake pads and clutch friction discs because of the negative factors associated with metals such as copper. To gain more insight into the failure mechanism of the recent invention during brake or clutch applications, a nonlinear transient thermomechanical model is established using Finite Element Code. The model is based on a two-dimensional configuration for an investigation on the onset of TMI (Thermo-Mechanical Instability) during sliding contact in such material. The model is validated by comparing the transient simulation results for a full-contact regime to the result from the existing eigenvalue method. A parametric study is carried out to examine how the thermal conductivities and the elastic moduli influence TMI. The simulation results show that the thermal conductivities in the transverse direction and elastic moduli in the longitudinal direction can stabilize the system.
Technical Paper

Development of a Simulation for a Shim Durability Test

2021-10-11
2021-01-1283
Shim durability is an important aspect of shim performance. During the brake operation, no mechanical failure of the shim is allowed. Typically, when releasing a shim into production, durability tests must be performed to ensure no failure occurs around the locator holes, and the shim does not walk over the locators. Since the durability test requires an actual pad and shim, the mechanical retention mechanism for the shim (locators) need to be designed, and backplates must be produced. If a failure is detected during these durability tests, either the shim needs to be changed or the retention locators have to be redesigned, which could negatively impact NVH performance and project timing/costs. In this paper, a finite element model is developed to simulate a stop in a shim durability test. The model can be used to predict stress levels at the shim’s locator holes and the failure mode of a shim during a durability test stop.
Technical Paper

Analysis of the Effect of the Wedged Type Brake Caliper Piston on Brake Drag

2021-10-11
2021-01-1293
Recently, there’s a massive flow of change in the automotive industry with the coming era of electric vehicles and self-driving (autonomous) vehicles. The automotive braking system field is not an exception for the change and there are not only lots of new systems being developed but also demands for researches for optimizations of conventional brake systems fitting to the newly appeared systems such as E-Booster and Electric Motor Brake (EMB) Caliper. Taking the Electric Motor Brake Caliper for example, it is considered as a very important and useful system for autonomous vehicles because the motor actuator of the caliper is much easier to control with ECUs compared to the conventional hydraulic pressure system. However, easy of control is not the only thing that excites brake system engineers.
Technical Paper

Dynamic Brake Test Stand

2021-10-11
2021-01-1274
Nowadays, inertia dynamometers or roller dynamometers are used for the development and testing of vehicle brakes. However, these testing methods are either entirely unable to simulate dynamical conditions, close to real driving maneuvers, or they can do so approximately only at very high costs. This means that brakes, braking systems and brake-related assistance systems such as the ESC system can ultimately only be tested in a full prototype of the car, or before that on hardware-in-the-loop test stands. In the case of the ESC, these test stands have to simulate the behavior of the brake and the surrounding vehicle in real time, then stimulate the interfaces of the ESC sensors accordingly, and finally evaluate the reaction of the ESC system in different situations. The problem here, however, is that the braking system can only be approximated by simulations.
Technical Paper

Research on Trajectory Planning and Tracking Strategy of Lane-changing and Overtaking based on PI-MPC Dual Controllers

2021-10-11
2021-01-1262
Aiming at the problem of poor robustness after the combination of lateral kinematics control and lateral dynamics control when an autonomous vehicle decelerates and changes lanes to overtake at a certain distance. This paper proposes a trajectory determination and tracking control method based on a PI-MPC dual algorithm controller. To describe the longitudinal deceleration that satisfies the lateral acceleration limit during a certain distance of lane change, firstly, a fifth-order polynomial and a uniform deceleration motion formula are established to express the lateral and longitudinal displacements, and a model prediction controller (MPC) is used to output the front wheel rotation angle. Through the dynamic formula and the speed proportional-integral (PI) controller to control and adjust the brake pressure.
Technical Paper

Application of Brake System Failed State Performance and Reliability Requirements to Brake System Architecting

2021-10-11
2021-01-1267
The modern braking system in the field today may be controlled by over a million lines of computer code and may feature several hundred moving parts. Although modern brake systems generally deliver performance, even with partial failures present in the system, that is well above regulatory minimums, they also have a level of complexity that extends well beyond what the authors of existing regulations had envisioned. Complexity in the braking system is poised for significant increases as advanced technologies such as self-driving vehicles are introduced, and as multiple systems are linked together to provide vehicle-level “features” to the driver such as deceleration (which can invoke service braking, regenerative braking, use of the parking brake, and engine braking). Rigorous safety-case analysis is critical to bring a new brake system concept to market but may be too tedious and rely on too many assumptions to be useful in the early architecting stages of new vehicle development.
Technical Paper

In-Depth Considerations for Electric Vehicle Braking Systems Operation with Steep Elevation Changes and Trailering

2021-10-11
2021-01-1263
As the automotive industry prepares to roll out an unprecedented range of fully electric propulsion vehicle models over the next few years - it really brings to a head for folks responsible for brakes what used to be the subject of hypothetical musings and are now pivotal questions for system design. How do we really go about designing brakes for electric vehicles, in particular, for the well-known limit condition of descending a steep grade? What is really an “optimal’ design for brakes considering the imperatives for the entire vehicle? What are the real “limit conditions” for usage that drive the fundamental design? Are there really electric charging stations planned for or even already existing in high elevations that can affect regenerative brake capacity on the way down? What should be communicated to drivers (if anything) about driving habits for electric vehicles in routes with significant elevation change?
Technical Paper

Investigations on the Deposition Behaviour of Brake Wear Particles on the Wheel Surface

2021-10-11
2021-01-1301
The deposition behavior of brake wear particles on the surface of a wheel and the mechanisms on it have not been fully understood. In addition, the proportion of brake wear particles deposited on the wheel surface compared to the total emitted particles is almost unknown. This information is necessary to evaluate the number- and mass-related emission factors measured on the inertia dynamometer and to compare them with on-road and vehicle-related emission behaviour. The aim of this study is to clarify the deposition behavior of brake particles on the wheel surface. First, the real deposition behaviour is determined in on-road tests. For particle sampling, collection pads are adapted at different positions of a front and rear axle wheel. In addition to a Real Driving Emissions (RDE)-compliant test cycle, tests are performed in urban, rural and motorway sections to evaluate speed-dependent influences.
Technical Paper

Design and Analysis of a Pneumatically Actuated Drag Reduction System

2021-10-05
2021-01-5080
The main goal of race car aerodynamics is to generate a desired intensity of downforce for the least possible amount of drag. Nonetheless, the balance of the forces under all circumstances due to speed and acceleration is equally important. The modeling was performed using SolidWorks, and the analysis was done both analytically and by means of computational fluid dynamics (CFD) using a flow simulation with STAR-CCM+. The aerodynamics package, which includes the rear wing, front wing, and undertray that help in faster cornering, is analyzed in the full-car analysis. The full-car analysis is done for pitch and yaw. The increase in cornering ability can come from two major aspects: an increase in the aerodynamic downforce and a decrease in the aerodynamic drag of the vehicle. In order to implement the desired aerodynamics package, an airfoil with a predefined profile was selected. The main factor that limits the selection of an airfoil is its effectiveness at low velocities.
Technical Paper

A New Approach to Describe Thermal Aging of Automotive Catalysts Containing Precious Metal Alloys

2021-10-04
2021-01-5095
Regarding thermal real-world aging of automotive catalysts, no deeply developed model or correlation is yet available. Therefore, a new method is developed. A diesel oxidation catalyst (DOC) is aged in the oven and indicated a systematic crystallite growth. Additionally, catalytic deactivation is only dependent on the crystallite size. The crystallite size acts as an indicator for the precious group metal (PGM) surface. This determines a quantitative correlation between the temperature stress, the crystallite size, and, finally, the catalytic activity for oven-aged samples of a DOC. On the basis of this result, the method for the description of oven aging is worked out. It is a physical model that gets as input parameters the aging temperature and aging time for oven aging. This information can be used to calculate the crystallite growth. Further, the corresponding catalytic activity for all species (NO, CO, HC) can also get calculated.
Technical Paper

A Parametric Approach of IP Duct Vane Articulation Study for Enhanced Cabin Cool Down Performance

2021-10-01
2021-28-0200
The cabin cool down performance is influenced by heat load, AC system components and Air handling components. The air handling components are AC duct, vane and vent. Design of AC duct vane plays a crucial role in the airflow directivity in cabin which enhances the cabin cool down performance. Simulations are carried out by rotating the vanes manually and requires post process for every iteration. It leads to more time consuming and more number of simulations to achieve the target value. Research articles focusing on automation and optimization of vane articulation studies are scanty. Thus, the objective of this work is to execute the vane articulation study with less manual intervention. A parametric approach is developed by integrating ANSA and ANSYS FLUENT tools. With Direct Fit Morphing and DoE study approach from ANSA delivers the surface mesh model for the different vane angle configurations.
Technical Paper

Vibration Analysis of Fully Perforated Rectangular Plates with Circular Perforations

2021-10-01
2021-28-0195
Perforated plates have a variety of applications in different fields, some of which are agriculture, aerospace, acoustics, automotive, manufacturing, and mining. Owing to its usability in diverse technological domains, a considerable amount of research has been done to understand the various mechanical characteristics of fully perforated plates. Be that as it may, vibration characteristics of fully perforated rectangular plates made of SAE 416L Stainless steel with parallel and zig-zag pattern of perforations have not been reported yet and thus, this work aims to bridge the identified gap by using the finite element method. The required models are generated and simulated using respective computational softwares. The diameter of the perforation and sheet thickness are the parameters of variation, whose effects on the first six modal frequencies of the rectangular plate are analyzed and documented in this study.
Technical Paper

Vibration Analysis of Gear Defects using Machine Learning Approach

2021-10-01
2021-28-0182
Gear drives are considered as the most effective transmission method in automobiles as well as in various industries because of its high efficiency, reliability and high velocity ratio. As a result, from its trustful usage, failure in any part may lead to a large and unpredictable production loss along with massive service cost and safety concerns. Scheduled condition monitoring and Periodic maintenance are the only solution to avoid the above scenario. Vibration analysis is the most sounded term in fault detection due to its runtime condition monitoring and low cost. Nowadays, vibration analysis has been offset to the machine learning methods, which is a modern technique enabling us to automate such that the system can learn from the input data and make decisions with a nominal human interface whereas conventional methods are highly operator dependent. Here in this study, the effectiveness of a machine learning based gear fault diagnosis system is carried out.
Technical Paper

Optimization of Spring-Damper Orientation in Double-Wishbone Type Suspension Geometry Using Genetic Algorithm in Python

2021-10-01
2021-28-0256
Orientation of the spring-damper system in a suspension geometry is a critical but hidden factor in vehicle performance characteristics. Spring and damper mounting characteristics are the significant factors to ensure proper contact of the tire with the ground, maintaining ride height, minimizing forces on spring, smooth ride, and driver comfort. Determining the spring orientation is conventionally a long and iterative process that involves computational simulations and processing of analytical expressions, which should align with the practical vehicle constraints. Due to numerous possible orientations, the designer would randomly pick the orientation and do the simulation, which reduces the reliability of the solution and the better solutions remain unexplored. This paper proposes a new methodology to optimize spring damper orientation in a suspension geometry using a genetic algorithm in Python Programming Language.
Technical Paper

Experimental Study on SS 304 Sheet Metal for Bending Process Optimization using Response Surface Method

2021-10-01
2021-28-0268
Productivity plays a vital role in manufacturing processes as well as in service. Sheet metal bending process is a type of forming process that has been used by the wide range in industries. There are several tangible and intangible factors affecting the production rate during the bending process. Spring back is one of the severe factors which affects the production rate, especially in stainless steel material. The spring back is mostly affected by material properties, sheet thickness, bending radius, die sizes and component geometry. In this paper, the spring back is studied by the effect of various parameters such as rectangle/oblong slots with varying pitch distance and without slots and bending time in the stainless-steel material 304 grade in V-air bending machine. The experimental data are evaluated by means of the Response Surface Method (RSM). Finally, it was observed that explored results have the betterment of the production rate with connection to spring back.
Technical Paper

Application of Taguchi Approach on Wire Electrical Discharge Machining of SS304

2021-10-01
2021-28-0271
SS304 (Stainless Steel 304) is a nickel- chromium based alloy, that is extensively used for the applications like cryogenic vessels, valves, refrigerator equipment and evaporators because of its high corrosion resistance, ductility and ability to remain as solid up to a temperature of 14000 C. SS304 is one of the tough to machine materials by conventional methods of machining. Wire Electrical Discharge Machining (WEDM) facilitates the ease of machining complicated cuts with hard to machine, conductive materials where high surface finish is required. In this investigation, a study has been done on WEDM of SS304 and mainly to optimize the process parameters during the machining of SS304 by using Taguchi’s analysis. Taguchi’s DoE approach is used to plan the experimental runs and by considering the process parameters such as pulse on time, pulse off time and peak current at three different levels the experiments were conducted.
Technical Paper

Simulation Driven Methodology for Shift Fork with Optimum Stiffness Symmetry

2021-10-01
2021-28-0244
Shift fork is a key shifting element in manual and dual clutch transmission for smooth operations of gear shifting. One of the main criteria for robust design of shift fork is stiffness symmetry. Stiffness symmetry ensures straight movement of sleeve onto hub and thus helps in achieving good shift quality. Stiffness symmetry also ensures equal load distribution across two or three pads of shift fork while in operation. In this paper, we intend to demonstrate finite element simulation driven design process to improve stiffness symmetry of shift fork. Various parameters affecting stiffness symmetry are analyzed through design of experiment and selected best range for optimum design of shift fork. Output of this study will be useful for improving any design of shift fork to meet different targets of stiffness symmetry for all automobile suppliers and manufactures.
X