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Viewing 1 to 30 of 4234
2015-09-29
Technical Paper
2015-01-2867
Sanket Pawar
Off-road commercial vehicles work for extended duration of time in the field on daily basis, typically more than 10-12 hours a day. Due to this, they need to spend substantial amount of time working in dark conditions in remote areas without compromising on efficiency and safety aspects. At such places proper lighting conditions are not available and off-road vehicles are bestowed with the task of fulfilling this need on their own. To secure safety, sufficient visibility is required around the vehicle. Due to their massive size and height, these off-road commercial vehicles need several high power work lights on each side of the vehicle to ensure flooding of the area around it with light thereby creating suitable working conditions for operator. Work lights consume high amperage of current. Higher the intensity of light higher would be the rating of the light in terms of wattage. Since, the battery voltage is fixed; it is the sinking current of the light that increases with wattage.
2015-09-29
Technical Paper
2015-01-2892
Carlos A. Pereira, Max Morton, Claire Martin, Geert-Jan Schellekens
The current trend towards energy efficient commercial vehicles requires a substantial improvement in their aerodynamic performance. The two largest contributions to the drag of a tractor-trailer combination are the wake at the rear of the trailer and the turbulent in-flow at the trailer gap. By integrating into the design of the roof fairing ducts that divert and speed-up air flow it is possible to obtain a reduction of drag in the trailer gap and alter the trailer wake favorably. The resulting decrease in yaw-averaged overall drag coefficient is of 5.8%. This translates into an improvement in fuel efficiency of 3% when compared to the baseline . The design optimization was performed using parametric variation of a computational fluid dynamic model at zero and six degree yaw.
2015-09-29
Technical Paper
2015-01-2894
Marius-Dorin Surcel, Mithun Shetty
The performance of several aerodynamic technologies and approaches, such as trailer skirts, trailer boat tails, gap deflectors and gap reduction, was evaluated using track testing, model wind tunnel testing, and CFD simulation, in order to assess the influence of the design, position and combination of various aerodynamic devices. Scale model wind tunnel tests were conducted to have the best direct performance comparisons between several possible configurations. The track test procedure followed the SAE J1321 SAE Fuel Consumption Test Procedure - Type II. The wind tunnel tests were conducted on a 1/8 scale model of a tractor in combination with a 53-foot semi-trailer. The tests consisted of two phases: setting the initial baseline, and component testing of various configurations.
2015-09-15
Technical Paper
2015-01-2614
Hideki Okada, Kenichi Kamimuki, Syuhei Yoshikawa, Shintaro Fukada
In the recent aircraft manufacturing, the cost reduction, the manufacturing time redaction and the weight saving of aircraft are strongly demanded. Refill Friction Spot Joining (FSJ, other word FSSW, Friction Stir Spot Welding) , which is one of innovative joining process based on friction stir welding, is a promising technology as the replacement for rivet and fastener, and this technology is expected to realize cost reduction and weight saving. Because Refill FSSW uses no additional materials such as Rivet, which contributes to reduce the weight. Also it needs no drilling and deburring process. It means easy to realize a high rate manufacturing, easy to use automation. Additionally, it helps to flexible designing of structures since it allows the closer joint pitch/edge distance than Rivet. In a previous report, the higher shear strength in comparison with Resistance spot welding was shown as well as it was comparable to Rivet.
2015-09-15
Technical Paper
2015-01-2514
Scott Tomchick, Joshua Elrod, Dave Eckstein, James Sample, Dan Sherick
A new, automated production method of installing Lightweight Groove Proportioned (LGP) and Hi-Lok bolts in wing panels has been implemented by Electroimpact, Inc. The system inserts LGP and Hi-Lok bolts into interference holes using a ball screw mechanical squeeze process supported by a back side rod-locked pneumatic clamp cylinder. Collars are fed and loaded onto a swage die retaining pin and swaging is performed through ball screw mechanical squeeze. Offset and straight collar locations are accommodated for 99.99% coverage of fastener diameters of 3/16", 1/4" and 5/16". Collar stripping forces are resolved using a dynamic ram inertial technique that reduces the pull on the work piece. Titanium TN nuts are fed and loaded into a socket with a retaining spring and installed on Hi-Loks with a Bosch right angle nut runner. Bolt installation and collar swage loads, as well as nut torque values are captured and logged for future reference.
2015-09-15
Technical Paper
2015-01-2615
Donald Jasurda
The aerospace industry is continually becoming more competitive. With an aircraft’s large number of components, and the large supplier base used to fabricate these components, it can be a daunting task to manage the quality status of all these parts in an accurate, timely and actionable manner. This paper focuses on an aircraft door assembly case study monitoring the process capability of machined parts at an aircraft OEM and their supply chain. Through the use of standardized measurement plans and statistical analysis of the measured output, the paper will illustrate how stakeholders can understand the process performance details at a workcell level, as well as overall line or plant performance in real time, in addition to automating standardized reporting. This ideal process begins in the product engineering phase using simulation to analyze the tolerance specifications and assembly process strategy, with one of the outputs being a production measurement plan.
2015-09-15
Technical Paper
2015-01-2493
Dan Vaughan, David Branson, Otto Jan Bakker, Svetan Ratchev
This paper evaluates the capability of adaptive fixtures to identify their suitability for implementation into aircraft wing manufacturing and assembly. The inherently complex aerospace industry requires a step change in its capability to achieve the production ramp up required to meet the global demand. To react to the inevitable differences between the measured dimension and the design definition, adaptive fixtures are utilised to improve process capability and therefore reduce non-conformance. However, the current utilisation of adaptive fixturing in the aerospace industry is low. To understand the potential benefits of these fixtures, an examination of the current academic practices and an evaluation of the existing industrial solutions is presented. The key enabling technologies are identified, their current technology readiness is evaluated and a technology road map for effective industrial implementation is discussed.
2015-09-15
Technical Paper
2015-01-2513
Hans-Juergen Borchers, Kadir Akkuş
New Aircraft drilling installations show a tendency to use Robotic concepts for the positioning of the end effector. At the same time demands of fulfilling the continually increasing customer requirements forces suppliers to improve their system solutions to match the specifications. This paper will discuss the process of drilling large diameter holes within high quality requirements using a Robot positioning concept with a High speed spindle End effector. This Robot End effector system provides flexibility to handle different aircraft sections due to its Robot arm design. The material configuration that will discussed in this paper is a mixed material stack of CFRP and Aluminum. The diameter range is from 7.9 mm to 15.9 mm. This paper will focus on the large diameter holes. What are the process forces that have to be handled and what are the solutions.
2015-09-15
Technical Paper
2015-01-2515
Adlai Felser, Peter B. Zieve, Bryan Ernsdorff
A new style of rivet injector is in production use on a variety of fastening machines used by major aircraft manufactureres. In this injector the opposing sides of the rivet guide blocks are attached to the arms of a parallel gripper. The parallel gripper performs three functions: 1. The closing action of the gripper closes the guide chutes to squeeze on the rivet and control its position. Air pressure actuates the gripper closed. By adjusting the air pressure the squeeze on the rivet can be adjusted. The squeeze prevents the rivet from “flying through”. 2. Reversing the air pressure on the gripper opens the arms of the injector and allows a convenient purge function. We use a parallel gripper with a 25mm stroke to provide a generous gap for purge. 3. In one application we are feeding ¼, 5/16 and 3/8 diameter rivets successfully though the same injector due to the synchronized motion of the parallel gripper.
2015-09-15
Technical Paper
2015-01-2503
Thomas Dr. Schneider
Accurate positioning of aircraft components constitutes a key task in the structural assembly of aircraft. Due to the fact that the precise alignment of the pre-built parts can reduce aerodynamic resistance and thereby reduce fuel consumption having the latest techniques and technologies for the alignment is crucial. Also having the opportunity to align the pre-built parts with a best fit operation to countervail component tolerances makes the production process even more effective. One of the main challenges is to keep the advanced technology affordable for the customer and keep the maintenance and spare part cost to a minimum. Furthermore the operation of the equipment must be less complex so it can be done by a normal worker. To meet these requirements and to fulfil the individual customer needs a modular product strategy based on standardized function groups is what you need. This includes the positioning units, the controls, the measurement interface and the product supports.
2015-09-15
Technical Paper
2015-01-2402
Yucheng Liu
Differential equations play a prominent role in aerospace engineering by modeling aerospace structures, describing important phenomena, and simulating mathematical behavior of aerospace dynamical systems. Presently, aerospace systems have become more complex, space vehicle missions require more hours of simulation time to complete a maneuver, and high-performance missiles require more logical decisions in there phases of flight. Because of these conditions, a computationally efficient algorithm for solving these differential equations is highly demanded to significantly reduce the computing time. This paper presents an efficient method for solving the differential equations by using variational iteration method, which can be implemented into software package to dramatically reduce the computing time for simulating the aerospace systems thereby significantly improving computer’s performance in real-time design and simulation of aircrafts, spacecrafts, and other aerospace vehicles.
2015-09-15
Technical Paper
2015-01-2504
Christian Meiners, Weidong Zhu, Yinglin Ke
The joining and assembly of barrel sections of large aircraft is always cumbersome. Any means to ease this task are welcome. In recent years The Boeing Co. has invented and licensed their “Flex-Track” system. But however flexible this approach may be, double curved surfaces, large variations of cross-section radius and issues with vacuum cup fixture are problems to be dealt with. Zhejiang University in Hangzhou, China has developed a new, innovative circumferential splicing system in cooperation with Broetje-Automation, Germany. This paper will describe design and features. There is a unique, time-saving setup technology and self-stepping actuation for a one up 360° splicing operation. The process endeffector is based on standard, state of the art components in use for large fastening systems.
2015-09-15
Technical Paper
2015-01-2613
Douglas Leicht, Kirk Olsen
15-5PH is a precipitation-hardening, martensitic stainless steel used for primary structural elements such as engine mounts where corrosion resistance, high strength, good fatigue and fracture toughness is required. The material composition is defined in AMS5659M and can be either type 1-vacuum arc remelt (VAR) or type 2-electro slag remelt (ESR) heat treated per SAE AMS-H-6875B to condition H1025 to an ultimate tensile strength of 155-175 ksi. Typical material handbooks have limited fatigue data which are only type 1 material. Therefore, the fatigue properties of 15-5 PH H1025 stainless steel for both type 1 and type 2 were determined. The objective of the fatigue testing was to generate a family of S-N curves (maximum stress versus number of cycles to failure) for a series of stress ratios across the entire range of cycles to failure.
2015-09-15
Technical Paper
2015-01-2626
Charla Wise
ABSTRACT
2015-09-15
Technical Paper
2015-01-2499
Perla Maiolino, Richard A. J. Woolley, Atanas Popov, Svetan Ratchev
Assembly and manufacture of aerospace structures, in particularly legacy products, relies heavily on the skill or rather craftsmanship of the human operator. Compounded by low volume rates the implementation of a fully automated production facility may not be cost effective. A more efficient solution is a mixture of both manual and automated operations but herein lays an issue of human error when stepping through the build from manual operation to an automated one. Some inline quality checking must take place, machine vision is an obvious choice yet it can be plagued with problems in shop floor environments. Here we demonstrate a robust solution using a low cost 3D scanner comprising of IR enabled adaptive depth detection. The system checks the quality of manually assembled sub components before automated robot controlled operations are undertaken.
2015-09-15
Technical Paper
2015-01-2594
Thomas G. Jefferson, Panorios Benardos, Svetan Ratchev
Current assembly systems that deal with large, complex structures present a number of challenges with regard to improving operational performance. Specifically, aerospace assembly systems comprise a vast array of interrelated elements interacting in a myriad of ways, resulting in a deeply complex process that requires a multi-disciplined team of engineers. The current approach to ramp-up production rate involves building additional main assembly fixtures which require large investment and lead times up to 24 months. Within Airbus Operations Ltd there is a requirement to improve the capacity and flexibility of assembly systems, thereby reducing non-recurring costs and time-to-market. Recent trends to improve manufacturing agility advocate Reconfigurable Assembly Systems (RAS) as a viable solution. Yet, adding reconfigurability to assembly systems further increases both the operational and design complexity.
2015-09-15
Technical Paper
2015-01-2491
Paul Haworth, Donald Peterson, Curtis Hayes
A new high speed forming process for fatigue rated index head rivets used in wing panel assembly using ball-screw based servo squeeze actuation has been developed. The new process is achieved using a combination of force and position control and is capable of forming to 40,000 lbs at rates of up to 200,000 lbs/second whilst holding the part location to within +/- 10 thousandths of an inch. Multi-axis riveting machines often have positioning axes that are also used for fastener upset. It is often the case that while a CNC is used for positioning control, another secondary controller is used to perform the fastener upset. In the new process, it has been possible to wrap the control of the upset process into the machine CNC and thus eliminating any separate controllers. The fastener upset force profile is controlled throughout the forming of the rivet by using a closed loop force control system that has a load cell mounted directly behind the stringer side forming tool.
2015-06-15
Technical Paper
2015-01-2302
Yuksel Gur, Jian Pan, David Wagner
Lightweighting of vehicle panels enclosing vehicle cabin causes NVH degradation since engine, road, and wind noise acoustic sources propagate to the vehicle interior through these panels. In order to reduce this NVH degradation, there is a need to develop new NVH sound package materials and designs for use in lightweight vehicle design. Statistical Energy Analysis (SEA) model can be an effective CAE design tool to develop NVH sound packages for use in lightweight vehicle design. Using SEA can help engineers recover the NVH deficiency created due to sheet metal lightweighting actions. Full vehicle SEA model was developed to evaluate the high frequency NVH performance of “Vehicle A” in the frequency range from 200 Hz to 10 kHz. This correlated SEA model was used for the vehicle sound package optimization studies. Full vehicle level NVH laboratory tests for engine and tire patch noise reduction were also conducted to demonstrate the performance of sound package designs on “Vehicle A”.
2015-06-15
Technical Paper
2015-01-2208
David Stotera, Scott Bombard
Abstract Both vehicle roof systems and vehicle door systems typically have viscoelastic material between the beams and the outer panel. These materials have the propensity to affect the vibration decay time and the vibration level of the panel with their damping and stiffening properties. Decay time relates to how pleasant a vehicle door sounds upon closing, and vibration level relates to how loud a roof boom noise may be perceived to be by vehicle occupants. If a surrogate panel could be used to evaluate decay time and vibration level, then a design of experiments (DOE) could be used to compare the effects of different factors on the system. The purpose of this paper is to show the effect of varying test factors on decay time and vibration level on a panel-beam system with viscoelastic material applied. The results were calculated using DOE software, and they were used to construct optimized systems for validation testing.
2015-06-15
Technical Paper
2015-01-2206
Glenn Yin, Alan Parrett, Nitish Wagh, Dennis Kinchen
Abstract In automotive noise control, the hood liner is an important acoustic part for mitigating engine noise. The random incidence absorption coefficient is used to quantify the component level acoustic performance. Generally, air gaps, type of substrate materials, density of the substrate materials and Air Flow Resistivity (AFR) of the cover scrim are the dominant control factors in the sound absorption performance. This paper describes a systematic experimental investigation of how these control factors affect flat sample performance. The first stage of this study is full factorial measurement based on current available solutions from sound absorber suppliers. The acoustic absorption of different hood liner constructions, with variations in materials, density, air gaps, and scrims was measured.
2015-06-15
Technical Paper
2015-01-2228
Kalyan Chakravarthy Addepalli, Natalie Remisoski, Anthony Sleath, Shyiping Liu
Abstract Drivelines used in modern pickup trucks commonly employ universal joints. This type of joint is responsible for second driveshaft order vibrations in the vehicle. Large displacements of the joint connecting the driveline and the rear axle have a detrimental effect on vehicle NVH. As leaf springs are critical energy absorbing elements that connect to the powertrain, they are used to restrain large axle windup angles. One of the most common types of leaf springs in use today is the multi-stage parabolic leaf spring. A simple SAE 3-link approximation is adequate for preliminary studies but it has been found to be inadequate to study axle windup. A vast body of literature exists on modeling leaf springs using nonlinear FEA and multibody simulations. However, these methods require significant amount of component level detail and measured data. As such, these techniques are not applicable for quick sensitivity studies at design conception stage.
2015-06-15
Technical Paper
2015-01-2079
Colin Hatch, Jason Moller, Eleftherios Kalochristianakis, Ian Roberts
Abstract The introduction of ice-phobic coatings promises to allow passive ice protection systems to be developed particularly for rotating systems such as propellers. The centrifugal force field combined with reduced adhesive strength can produce a self-shed capability limiting the amount of ice build-up. The size and shed time of ice shed from a propeller is predicted using a process that determines ice shape, ice growth rate and both internal and ice-structure interface stresses. A simple failure model is used to predict the onset of local failure and to propagate damage in the ice until local ice shedding is obtained. Recommendations are made on developing the model further.
2015-06-15
Technical Paper
2015-01-2102
Guilin Lei, Wei Dong, Jianjun Zhu, Mei Zheng
Abstract The numerical simulation of ice melting process on an iced helicopter rotor blade is presented. The ice melting model uses an enthalpy-porosity formulation, and treats the liquid-solid mushy zone as a porous zone with porosity equal to the liquid fraction. The ice shape on the blade section is obtained by the icing code with a dynamic mesh module. Both of the temperature change and the ice-melting process on the rotor blade section surface are analyzed. The phenomenon of ice melting is analyzed through the change of temperature and liquid fraction on the abrasion/ice interface. The liquid fraction change as with time on the abrasion/ice surface is observed, which describes the ice-melting process well. The numerical results show that the ice melting process can be simulated effectively by the melting model. The de-icing process can be monitored by observing the change of the liquid fraction of the area around the abrasion/ice interface.
2015-06-15
Technical Paper
2015-01-2103
Christian Bartels, Julien Cliquet, Carlos Bautista
Abstract In order to comply with applicable certification regulations, airframers have to demonstrate safe operation of their aircraft in icing conditions. Part of this demonstration is often a numerical prediction of the potential ice accretion on unprotected surfaces. The software ONICE2D, originally developed at the Office National d'Études et de Recherche Aérospatial (ONERA), is used at Airbus for predicting ice accretions on wing-like geometries. The original version of the software uses a flow solution of the 2D full-potential equation on a structured C-grid as basis for an ice accretion prediction. Because of known limitations of this approach, an interface was added between ONICE2D and TAU [6], a hybrid flow solver for the Navier-Stokes equations. The paper first details the approach selected to implement the interface to the hybrid flow solver TAU.
2015-06-15
Technical Paper
2015-01-2121
Yong Chen, Liang Fu
Abstract In helicopter, the icing rotor blades will decrease the effectiveness of the helicopter and endanger the lives of the pilots. The asymmetrical ice break-up and shedding could also lead to severe vibrations of the rotor blade. Ice break-up from the main rotor may strike the fuselage and tail rotor, even worse, find its way into the engine, which may cause serious aircraft accidents. An understanding of the mechanisms responsible for ice shedding process is necessary in order to optimize the helicopter rotor blade design and de-icing system to avoid hazardous ice shedding. In this paper, the ice shedding model is improved by introducing a bilinear cohesive zone model (CZM) to simulate the initiation and propagation of ice/blade interface crack. A maximum stress criterion is used to describe the failure occurred in the ice.
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
2015-01-2257
Ki-Chang Kim, Sang-Woo Lee, Seok-Gil Hong, Jay Kim, Gil-Jun Lee, Jae Min Choi, Yong-Jin Kim
Abstract Squeak and rattle (S&R) problems in body structure and trim parts have become serious issues for automakers because of their influence on the initial quality perception of consumers. In this study, various CAE and experimental methods developed by Hyundai Motors for squeak and rattle analysis of door systems are reported. Friction-induced vibration and noise generation mechanisms of a door system are studied by an intelligent combination of experimental and numerical methods. It is shown that the effect of degradation of plastics used in door trims can be estimated by a numerical model using the properties obtained experimentally. Effects of changes in material properties such as Young's modulus and loss factor due to the material degradation as well as statistical variations are predicted for several door system configurations. As a new concept, the rattle and squeak index is proposed, which can be used to guide the design.
2015-06-15
Technical Paper
2015-01-2290
Sivanandi Rajadurai, Guru Prasad Mani, Kavin Raja, Sundaravadivelu Mohan
Abstract Bending moment is one of the strongest pursuits in resonator's structural validation. Eigen problems play a key role in the stability and forced vibration analysis of structures. This paper explains the methodology to determine the weak points in the resonator assembly considering the additional effects of the installation forces and temperature impacts. Using strain energy plots, weakest part of the product is identified in the initial stage. The solution comes in unique way of utilizing the worst case scenarios possible. As a consequence, the stress generated by these analyses will prove to be critical in concerning the durability issue of the system. These conditions are evaluated by a finite element model through linear approaches and results are summarized.
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.
2015-06-15
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).
Viewing 1 to 30 of 4234