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Technical Paper

Engine Exhaust noise optimization using Sobol DoE sequence and NSGA-II Algorithms.

2019-06-05
2019-01-1483
Exhaust muffler is the most important component for overall vehicle noise signature. Optimized design of exhaust system plays a vital role in engine performance as well as auditory comfort. Exhaust orifice noise reduction is often contradicted by increased back pressure and packaging space. The process of arriving at exhaust design, which meets packaging space, back pressure and orifice noise requirements, is often manual and time consuming. Therefore, an automated numerical technique is needed for this multi-objective optimization. In current case study, a tractor exhaust system has been subjected to Design of Experiments (DoE) using SOBOL sequencing algorithm and optimized using NSGA-II algorithm. Target design space of the exhaust muffler is identified and modeled considering available packaging constrain. Various exhaust design parameters like; length of internal pipes, location of baffles and perforation etc. are defined as input variables.
Technical Paper

Development of an Accelerated Laboratory Test to Simulate Real-World Tire Flat-Spotting

2019-06-05
2019-01-1509
Tire flat-spotting occurs when tires remain in a loaded condition without rolling for an extended period of time, and can be temporary or permanent depending on the length of storage, vehicle loading and environmental factors. Tire non-uniformity caused due to flat-spots often induce shake and shimmy vibration in vehicles due to increased tire-wheel force variation input into the chassis. This results in increased warranty costs for OEMs / tire suppliers and customer dissatisfaction in third-party quality surveys such as J. D. Power IQS. Flat-spotting is of particular concern for slow-moving vehicle inventory that remains parked for long periods at OEM plants and/or dealership lots. OEMs often stipulate or recommend inventory storage practices for dealers that require physical movement of vehicles every 30 days to reduce the risk of tires developing permanent flat-spots.
Technical Paper

Investigating collaborative robot gripper configurations for simple fabric pick and place tasks

2019-04-02
2019-01-0699
Fiber composite materials are widely used in many industrial applications – specially in automotive, aviation and consumer goods. Introducing light-weighting material solutions to reduce vehicle mass is driving innovative materials research activities as polymer composites offer high specific stiffness and strength compared to contemporary engineering materials. However, there are issues related to high production volume, automation strategies and handling methods. The state of the art for the production of these light-weight flexible textile or composite fiber products is setting up multi-stage manual operations for hand layups. Material handling of flexible textile/fiber components is a process bottleneck. Consequently, the long term research goal is to develop semi-automated pick and place processes for flexible materials utilizing collaborative robots within the process. Collaborative robots allow for interactive human-machine tasks to be conducted.
Technical Paper

The Differential Braking Steering Control of Special Purpose Flat-Bed Electric Vehicle

2019-04-02
2019-01-0440
Special purpose flat-bed vehicle is commonly utilized to move heavily items such as containers in warehouse, port and other freight handling scene, the hydraulic steering system have be gradually replaced by electric ones. However, the cost of electric steering system is high for commercial activities. Thus, for some corporates, the differential braking steering strategy becomes an ideal alternative. The purpose of this paper is to present a steering control method for flat-bed electric vehicle based on differential braking system. There are two main components of the control method, steering while moving forward and pivot steering, and each of them was composed by upper layer and executive layer. To evaluate the practicability of the control methods, a 7-DOF flat-bed vehicle model was established in Simulink.
Technical Paper

Advances in Tank Heaters Based on PTC (Positive Temperature Coefficient) Plastic Nanomaterials

2019-04-02
2019-01-0152
The global trend on emission reduction is leading to a wider diffusion of SCR systems for diesel engines and to the introduction of WI (water injection) systems in gasoline engines. Cars are equipped with tanks for water and urea solutions (AD-blue). Both liquids can freeze in the car operative temperature range: the tanks must be equipped with heaters to guarantee a sufficient amount of additives in liquid form in any condition. We propose solutions based on plastic PTC (in the following nanoPTC) effect nanomaterials for thermal management of those liquids. The proposed heaters can be molded in any shape, following the specific constraints of each tank, in carpet like shapes for a distributed heating of the tank, or in bulky components integrating sensors housings, pipes, pumping systems or in the packaging of other components. The PTC effect is distributed avoiding overheating in parts with poor thermal exchange (dry condition).
Technical Paper

The Adaptive Cycle Engine on Standard Duty Cycles

2019-04-02
2019-01-0232
Continuing research introduced at the 2018 WCX conference, this paper shows the result of simulations where a midsize sedan (1700 kg) fitted with an adaptive cycle engine and a CVT is operated over three standard duty cycles: US06, UDDS, and HWFET, and compared with the results obtained from other engine cycles installed on the same vehicle. Four different engine cycles are compared: conventional 4-stroke, 6-stroke cycle with no air storage, 6-stroke cycle with air storage, and fully adaptive cycle with air storage and a number of strokes determined by instantaneous demand and state of charge of the storage tank. Results show that the fully adaptive engine achieves a better mileage in all scenarios, closely followed by the partially adaptive 6-stroke cycle with storage. Gains over a conventional 4-stroke powerplant range from 3.4 mpg on the HWFET cycle, to 7.6 mpg on the UDDS cycle.
Technical Paper

Aerodynamic Development of the 2019 Chevrolet Corvette C7 ZR1

2019-04-02
2019-01-0665
This paper presents an overview of the aerodynamic development of the 2019 Chevrolet Corvette C7 ZR1. Extensive wind tunnel testing and computational fluid dynamics simulations were completed to engineer the ZR1’s aerodynamics to improve lift-to-drag efficiency and track capability over previous Corvette offerings. The ZR1 architecture changes posed many aerodynamic challenges including increased vehicle cooling, strict packaging demands, wider front track width, and aggressive exterior styling. Through motorsports-inspired aerodynamic development, the ZR1 was engineered to overcome these challenges through the creation of new devices such as a raised rear wing and front underwing. The resulting Standard ZR1 achieved a top speed of 212 mph making it the fastest Corvette ever [1]. Optionally, the ZR1 with the ZTK Performance Package provides the highest downforce of any Corvette, generating approximately 950 pounds at the ZTK’s top speed [1].
Technical Paper

High Precise Benchmarks by CSD (Computational Solid Dynamics) with Meshfree Methods

2019-04-02
2019-01-0797
The virtual optimisation of tooling equipment is nowadays one of the common challenges in mechanical serial production. Even some numerical Eulerian approaches (grid-based) exist for modelling solid materials under dynamic loading, most of them are not very successful. Especially the solids undergoing large deformation and the subsequent material separation and propagating cracks demonstrate the limitations: variables become discontinuous across the crack surface, and the computational domain loses its continuum nature. Grid-based methods are not naturally equipped to deal with such situations due to the mesh distortion, mesh entanglement and requirement of mesh refinement. Very promising alternatives to the Eulerian methods are meshfree Lagrangian methods. Among them, smoothed particle hydrodynamics (SPH) is entirely meshfree and naturally equipped to handle large material deformation. In SPH the computational domain is discretised by a set of particles.
Technical Paper

Duct Shape Optimization Using Multi-Objective and Geometrically Constrained Adjoint Solver

2019-04-02
2019-01-0823
In the recent years, adjoint optimization has gained popularity in the automotive industry with its growing applications. Since its inclusion in the mainstream commercial CFD solvers and its continuously added capabilities over the years, its productive usage became readily available to many engineers who were previously limited to interfacing the customized adjoint source code with CFD solvers. The purpose of this work is to demonstrate using an adjoint solver a method to optimize duct shape that meets multiple design objectives simultaneously. To overcome one of the biggest challenges in the duct design, i.e. the severe packaging constraints, the method here uses geometrically constrained adjoint to ensure that the optimum shape always fits into the user-defined packaging space. In this work, adjoint solver and surface sensitivity calculations are used to develop the optimization method.
Technical Paper

Optimizing the Defrost Vents to Meet FMVSS 103 in a Byton’s Electric Smart Vehicle

2019-04-02
2019-01-1069
FMVSS 103 is one of the requirements to be passed by any vehicle and it is mandatory by Federal Government. It requires that the defrost mechanism be robust enough to melt the ice off the glass in -20 C ambient within 30 minutes. In electric cars this is more challenging than traditional ICE cars as there is no heat from the ICE and the heat pump mode does not operate at such low temperatures. In Byton’s smart electric vehicle due to the oversized Coast to Coast screen which lead to lack of packaging space, having a proper impingement angle was not achievable so plenty of vanes and baffles were used to solve this problem. CAE/CFD was used as a powerful tool to optimize the geometry both in subsystem and whole cabin level. The CAE model is very comprehensive and includes phase-change of the ice on glass and whole cabin detailed geometry with four passengers. Afterwards, the test was conducted and is still in progress, and the correlation study will be completed in future articles.
Technical Paper

Approximating Convective Boundary Conditions for Transient Thermal Simulations with Surrogate Models for Thermal Packaging Studies

2019-04-02
2019-01-0904
The need for transient thermal simulations in vehicle packaging studies has grown rapidly in recent years. To date, the computational costs associated with the transient simulation of 3D conjugate heat transfer phenomena has prohibited the widespread use of full vehicle transient simulations. This paper presents results from a recent study that explored a method to circumvent the computational costs associated with long transient conjugate heat transfer simulations. The proposed method first segregates the thermal structural and fluid physics domains to take advantage of time scale differences. The two domains are then re-coupled to calculate a series of steady state conjugate heat transfer simulations at various vehicle speeds. The local convection terms are then used to construct a set of surrogate models dependent on vehicle speed, that predict the local heat transfer coefficients and the local near wall fluid temperatures.
Technical Paper

Evaluation of Navigation in Mobile Robots for Long-Term Autonomy in Automotive Manufacturing Environments

2019-04-02
2019-01-0505
In recent times, a number of reference implementations of Simultaneous Localization and Mapping (SLAM) and navigation techniques have been made publicly available via the ROS Community. Several implementations have transitioned to commercial products (vacuum robots, drones, warehouse robots, etc.). However, in such cases, they are specialized and optimized for their specific domains of deployment. In particular, their success criteria have been based primarily on mission completion and safety of humans around them. In this light, deployment in any new operational design domain (ODD) requires at least a careful verification of performance and often re-optimization. We seek the technological gaps that need to be addressed to ensure the mobile robots are fit for automotive manufacturing environments. Automotive final assembly environments pose significant additional challenges for mobile robot deployment.
Technical Paper

Reliability Physics Approach for High-Density Ball Grid Arrays in Autonomous Vehicle Applications

2019-04-02
2019-01-1251
Integration of advanced sensing systems in autonomous vehicles is possible due to high performance processors that utilize high-density ball grid array (HD-BGA) packaging. The configuration of advanced sensors within autonomous vehicles requires the placement of processing modules within non-conventional vehicles compartments that can drastically influence the reliability of HD-BGAs. Durability of HD-BGAs to different loads depend on their location within the vehicle as well as the form factor of the package itself. Reliability Physics Approach (RPA) combines simulation tools and empirical models to predict the reliability of advanced electronic packages under complex environmental and operational loads by identifying the susceptibility of electronic components to the dominant failure mechanism.
Technical Paper

Axiomatic Design of a Reconfigurable Assembly System for Aircraft Fuselages

2019-03-19
2019-01-1359
Modern aerospace industry develops assembly process lines for new aircraft which is produced on a single production line while shortening production times by new technologies. Production processes are developed with systems such as lightweight fixtures, reconfigurable tools, automated part positioning, automated scanning countersink control, automated riveting, robotic measurement etc. These systems provide the necessary flexibility for aircraft fuselage and wing assembly projects. Aerospace manufacturers invest in assembly lines in order to increase production rates and meet growing customer demands. Most of the investments are allocated to state-of-the-art robots for drilling and riveting, sealing, coating and painting applications, in addition to material handling, carbon fiber layup and different types of machining operations.
Technical Paper

Development of the Next Generation Flexible Tooling System

2019-03-19
2019-01-1362
Flexible Tooling Systems have been developed as a reconfigurable part support system to enable trimming of multiple part geometries utilizing a single router or waterjet. The driver for this development has been improved part quality, elimination of ergonomic issues associated with manually trimming, and the elimination of cost for part number specific hard tooling and the associated cost for manufacturing, maintenance, and storage. This paper will briefly trace the evolution of aerospace parts trimming history. The remainder of the report will focus on the technical objectives associated with the development of the Next Generation Flexible Tooling System, how they were achieved including the process for validation of each support location in aircraft coordinates. This system is designed to increase part holding accuracy with specific support location validation, and significantly reduce system maintenance costs in wet or dry environments.
Standard

350 °F Autoclave Cure, Low Flow Toughened Epoxy Prepregs

2019-03-12
WIP
AMS3961A
The intent of this specification is for the procurement of the material listed on the QPL and, therefore, no qualification or equivalency threshold values are provided. Users that intend to conduct a new material qualification or equivalency program shall refer to the Quality Assurance section of this base specification, AMS3961. All material qualification and equivalency data has been archived and is available for review upon request. Contact the CMH-17 Secretariat (www.cmh17.org) for additional information.
Article

Aerospace manufacturers turn to non-hazardous PVD coatings as regulations tighten on toxic hard chrome plating

2019-03-08
The search for a suitable replacement to hard chrome plating on aerospace components has been a key supply chain priority for aircraft manufacturers. This is because of the documented health risks to workers and the impact on the environment from exposure to hexavalent chromium, a carcinogen that occurs during the chrome plating process and the most toxic form of chromium.
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