Browse Topic: Assembling

Items (6,003)
ABSTRACT This work presents the development and application of an optimization algorithm for simultaneously improving the fatigue life and minimizing a representative manufacturing cost when assembling a ground combat vehicle. High stress in the occupied space of the weld decreases the fatigue life of the structure; therefore, by minimizing the weld’s exposure to high stresses, the structure’s life can be improved. The new capability for simultaneously improving the fatigue life of a welded structure while reducing a manufacturing cost is demonstrated by considering the welding of a representative panel of a v-hull. Selections are made for the weld placement, the weld type, and the type of filler material, in order to minimize exposure to high stresses and therefore maximize fatigue life. In addition to the stress evaluation, the optimization considers manufacturing cost as another objective in parallel. The final evaluation provides an assembly design to increase the fatigue life and
Mayhood, CarlyVlahopoulos, Nickolas
This document is intended for discrete and integrated digital, wavelength division multiplexing (WDM), and analog/radio frequency (RF) photonic components developed for eventual transition to aerospace platforms. The document provides the reasons for verification of photonic device life test and packaging durability. The document focuses on pre-qualification activity at the optical component level to achieve TRL 6. The recommended tests in this document are intended to excite typical failure mechanisms encountered with photonic devices in an aerospace operating environment, and to build confidence that a technology is qualifiable during a program’s engineering and manufacturing development phase. This recommended practice is targeting components to support electrical-to-optical, optical-to-electrical, or optical-to-optical functionality. Passive optical waveguide, fiber optic cable, and connector components that are integral to a photonic package are included. Component and photonic
AS-3 Fiber Optics and Applied Photonics Committee
This document provides an orientation to fusion splicing technology for optical fibers and fiber optic cable. It is intended for managers, designers, installers, and repair and maintenance personnel who need to understand the process of fusion splicing. This technology is widely used in telecommunications and industrial applications, and is finding acceptance in aerospace applications
AS-3 Fiber Optics and Applied Photonics Committee
In electric vehicle applications, the majority of the traction motors can be categorized as Permanent Magnet (PM) motors due to their outstanding performance. As indicated in the name, there are strong permanent magnets used inside the rotor of the motor, which interacts with the stator and causes strong magnetic pulling force during the assembly process. How to estimate this magnetic pulling force can be critical for manufacturing safety and efficiency. In this paper, a full 3D magnetostatic model has been proposed to calculate the baseline force using a dummy non-slotted cylinder stator and a simplified rotor for less meshing elements. Then, the full 360 deg model is simplified to a half-pole model based on motor symmetry to save the simulation time from 2 days to 2 hours. A rotor position sweep was conducted to find the maximum pulling force position. The result shows that the max pulling force happens when the rotor is 1% overlapping with the stator core. The impact of asymmetric
Gong, ChengChang, LeHe, SongZhang, PengMuir, Michael
The process of assembling the bearing and crimp ring to the steering pinion shaft is intricate. The bearing is pressed into its position via the crimp ring, which is tipped inward and fully fitted into a groove on the pinion shaft. Only when the bearing is pressed to a low surface on the pinion shaft, the caulking force for the crimp ring is achieved. The final caulking distance for the crimp ring confirms the proper bearing position. Simulating this transient fitting process using CAE is a challenging topic. Key factors include controlling applied force, defining contact between bearing and pinion surface, and defining contact between crimp ring and bearing surface from full close to half open transition. The overall CAE process is validated through correlation with testing
Song, GavinVlademar, MichaelVenugopal, Narayana
In order to realize the series-parallel switching control of hybrid electric vehicle (HEV) with dual-motor hybrid configuration, a method of unpowered interrupt switching based on the coordinated control of three power sources was proposed by analyzing the series-parallel driving mode of the dual-motor hybrid configuration. The series to parallel switching process is divided into three stages: speed regulation stage, clutch combination and power source switching. The distribution control of speed regulating torque is carried out in the speed regulating stage. The speed adjustment torque is preferentially allocated to the power source of the input shaft (engine and P1) to carry out the lifting torque. Due to the high speed adjustment accuracy and fast response of the P1 motor, the input shaft is preferentially allocated to P1 for speed adjustment, that is, the torque intervention of P1. If the speed control torque exceeds the intervention capacity of P1, then it is allocated to the
Jing, JunchaoZhang, JunzhiLiu, YiqiangHuang, WeishanDai, Zhengxing
In the pursuit of carbon emission reduction, hybridization has emerged as a significant trend in powertrain electrification. As a crucial aspect of hybrid powertrain system development, achieving high brake thermal efficiency (BTE) and a wide operating range with high efficiency are essential for hybrid engines to effectively integrate with the hybrid system. When developing dedicated hybrid engines (DHE), several design considerations come into play. First, in order to make efficient use of available resources and enable engine production on the same assembly line as conventional engines, it is crucial to maintain consistency in key design parameters of the cylinder head and block, thus extending the platform-based design approach. Among the key measures to achieve high BTE, cooled exhaust gas recirculation (EGR) has been extensively explored and proven effective in improving efficiency by mitigating knocking and reducing engine cooling heat loss. Fast combustion, acting as a
Xu, ZhengQiu, JieZhang, ZiQingCheng, ChuanhuiZhang, YaJunYang, YangWang, YingzhenLu, YuanZhou, ZhouLi, XiaoYang
Side doors are pivotal components of any vehicle, not only for their aesthetic and safety aspects but also due to their direct interaction with customers. Therefore, ensuring good structural performance of side doors is crucial, especially under various loading conditions during vehicle use. Among the vital performance criteria for door design, torsional stiffness plays an important role in ensuring an adequate life cycle of door. This paper focuses on investigating the impact of several door structural parameters on the torsional stiffness of side doors. These parameters include the positioning of the latch, the number of door side hinge mounting points on doors (single or double bolt), and the design of door inner panel with or without Tailor Welded Blank (TWB) construction. The findings of this study reveal that the change in latch position has the most significant influence on torsional stiffness, followed by the removal of TWB from the inner panel, upon implementation of suitable
Goyal, Vinay KumarSelvan, VeeraPandurangan, VenugopalUnadkat, SiddharthAlmeida, Neil Ricardo
The need for eco-friendly vehicle powertrains has increased drastically in recent years. The most critical component of an electric vehicle is the battery pack/cell. The choice of the appropriate cell directly determines the size, performance, range, life, and cost of the vehicle. Lithium-ion batteries with high energy density and higher cycle life play a crucial role in the progress of the electric vehicle. However, the packaging of lithium-ion cells is expected to meet lots of assembly demands to increase their life and improve their functional safety. Due to their low mechanical stability, the lithium-ion cell modules must have external pressure on the cell surface for improved performance. The cells must be stacked in a compressed condition to exert the desired pressure on the cell surface using compression foam/pads. The compression pads can be either packaged between each cell or once in every set of cells based on the cell assembly requirements. This paper describes the need for
Sithick Basha, AbubakkerChalumuru, MadhuSasikumar, K
One of the important aspects to consider at the design stage is the condensation of water vapor inside the lighting system, under specific weather conditions of temperature and humidity, which may compromise the device functionality. Condensation of water vapor is an issue affecting functional and aesthetics of Head Lamp. The current paper analyses the process of water vapor condensation inside an automotive LED head lamp. This paper also discusses the design methodology to avoid condensation under certain conditions. Design methodology includes design considerations for better air movement for thermal management, material selection, ease of moisture exchange, breather or vent selection, Vent placement. Additionally, this paper would also discuss about effective use of simulations tools, test methods and assembly process guidelines to avoid impact due to condensation. This paper would consist of one example with application of above methodology, its test and field results
Rane, Sandeep BaluPawar, Nishant
Automotive industry is a major contributor to global carbon dioxide (CO2) emissions and waste generation. Not only do vehicles produce emissions during usage, but they also generate emissions during production phase and end of life disposal. There is an urgent need to address sustainability and circularity issues in this sector. This paper explores how circularity and CO2 reduction principles can be applied to design and production of automotive parts, with the aim of reducing the environmental impact of these components throughout their life cycle. Also, this paper highlights the impact of design principles on End-of-Life Management of vehicles. As Design decisions of Component impacts up to 80% of emissions [1], it is important to focus on this phase for major contribution in reduction of emissions. Various factors such as material selection, quantity and weight of materials used in parts, design for durability, aerodynamic characteristics, design strategies, design for recycling
Ali, Rifat FahmidaHarel, SamarthShaikh, TahaChakraborty, Pinka
When asked about the most dreaded tasks on the manufacturing floor, many teams point to sanding, grinding, or polishing. These unforgiving tasks can be tedious, time-consuming, and hazardous, leading to respiratory illnesses and repetitive motion injuries. In today’s economic climate, finding workers willing to perform these taxing jobs can be challenging. Yet, they are often necessary when assembling metal, composite, or other parts into manufactured products
When deploying robots in an industrial setting, one of the primary goals is performance. In an industrial robot workcell, performance is often measured as cycle time: the time required to complete a set of tasks. Typical tasks include painting, welding, and inspecting. Regardless of the tasks, the goal is to complete them as fast as possible, so that the workcell can begin work on the next set of tasks. A long cycle time for a given cell can cause that cell to become the bottleneck on an assembly line
A team of researchers from Heidelberg University and Max Planck Institute for Medical Research have created a new technology to assemble matter in 3D. Their concept uses multiple acoustic holograms to generate pressure fields with which solid particles, gel beads, and even biological cells can be printed. These results pave the way for novel 3D cell culture techniques with applications in biomedical engineering
In an air brake system, compressed air is used as an energy medium for braking applications, ensuring a good seal between the components is critical. The sealing performance of gaskets are significant for the product with joint features as it affects functionality and can cause a breakdown of the entire system; hence, finite element simulation of the sealing performance of gaskets is important for any product development. To simulate fluid interacting with gasket, a fluid-structure interaction (FSI) simulation is necessary by co-simulating a computation fluid dynamics (CFD) and finite element analysis (FEA) solvers to capture complex behavior of seal deformation under dynamic conditions during leakage, but it is a time-consuming process. In this article, the sealing performance of gaskets is studied in detail only till the start of leakage. It is not necessary to simulate the dynamic behavior of the seal beyond leakage to validate the sealing performance; hence, static nonlinear
Dinesh Kumar, J.Vasanth Bharath, S.Hariharan, R.Suresh, S.
This paper investigates the problem of whine in the E-axle (Electric Drive Axle) system during acceleration of a light bus. The problem is identified as motor and reducer whine by the noise spectrum feature analysis method. Under the condition of ensuring motor performance and low cost, the motor whine is solved by optimizing the air tightness and sound insulation of the vehicle. Starting from gear microscopic shaping research, gear manufacturing and assembly process optimization was used to control gear whine. After testing and analysis, the means to effectively solve the E-axle system whine problem. The whine noise is optimized by about 8 dB (A). The results provide key technical support for the smooth production of the vehicle. It has certain guiding significance for the NVH (Noise, Vibration and Harshness) performance design and development of the E-axle system project
Chengping, ZhongGuo, FengSenhai, LiuQingshuang, ChenPing, XiaoDeng, XinXianzhong, Yu
NVH (Noise, Vibration and Harshness) of the electric drive axle (EDA) is a key attribute in electric-vehicle development. The NVH attributes of the EDA directly determines the driving comfort and customer feeling of the vehicle. Especially in pure electric working condition, the EDA noise is more perceptible by people without the engine noise masking. This paper investigates the abnormal noise in the vehicle caused by EDA. First, the filtered playback method is used to identify abnormal noise frequency between 330Hz and 430Hz.Adopted modal analysis, MASTA simulation, modulation noise analysis to identify problematic critical parts. The validity of the results is verified using the DOE method by part exchange, and finally locked to the source of gear parameters Rs and Fr. By adjusting the production process of gear and the second shaft, the assembly process error was avoided, and the gear parameter targets are formulated. The verification results of the whole vehicle assembly of small
Lun, WangQingshuang, ChenChengping, ZhongGuo, FengDeng, Xin
Current hybrid and electric powertrains in Class 1 through to Class 7 vehicle segments, are still disadvantaged by very low market penetration due to high procurement and operational cost barriers which have increased the gap between the technology experience and the expected benefits of powertrain electrification. Fundamentally, baseline gasoline and diesel vehicles with over 100 years of established supply chain network and manufacturing economies of scale, have made it difficult for hybrid and electric alternatives to compete even with the continuous drop in price of these new technologies and numerous government incentives. A new approach is proposed in this segment with an Integrated Torque Assist Transmission (ITAT) that addresses the typical fuel inefficiency challenges of the baseline powertrains where mostly up to 12% of their fuel content is used for actual vehicle propulsion while the rest is lost to heat dissipation. The new ITAT replaces the stock transmission as an
Nwoke, Ugo
The vehicle instrument panel (IP) system has several interactions with the surrounding components such as the Dash, Cowl, Cross Car Beam (CCB), Floor, Body Side etc. With such interactions comes different loadings, usage scenarios, interfaces and design challenges to overcome. For the specific case of the IP to Cowl & Dash interfaces, the position and performance in different load cases, such as, but not limited to, vibration and heat expansion loading as well as the assembly process. A design solution is required to enhance the performance in all these scenarios while maintaining the cost, weight & complexity as low as possible. This paper describes the development process of an optimized solution with a multi-disciplinary approach using advanced computer aided engineering (CAE) optimization tools, which involved performance in multiple virtual evaluations and mass. The achieved enhanced solution provides of multiple alternatives from early design stages to allow flexibility in the
Alonso, LilianaAlvarez, Ezequiel
SAE/USCAR-46 defines test methods and outputs for engine oil pump bench testing. Performance and durability testing are the primary focus of this standard. This is written to specifically address testing of electronically controlled variable displacement pumps but can be adapted to mechanically controlled pumps and other pump technologies as needed. This standard outlines critical inputs and outputs in order to perform the testing and report results, but does not specifically set the acceptance standards or pass/fail criteria. Acceptance criteria must be set by the customer
null, null
In rotor engineering, one must achieve a rotor design incorporating a well-controlled state of unbalance. A reduced nominal rotor unbalance assures achieving permissible vibration responses during measurement. Geometric feature controls associated with manufacturing drawings are root causes of vibratory measurements during engine testing. Difficulties arise during component design using software that fails to account for the presence of unbalance, or the ability to achieve a balanced state for each rotor design. Manufacturing procedures ensure that serial production articles are within tolerance limits established by the manufacturing drawings. This process is intended to ensure unbalance contributions estimated during the design phase will permit vibration limits to be met during final acceptance test. Performance of a rigid rotor under test cell conditions is dependent upon effective control of runout and eccentricity between mating components. Establishment of these tolerances must
Buschbeck, A.Hill, C.El-Sawaf, T.
The making of a quilt is an interesting process. Historically, a quilt is a canvas of work made from old pieces of cloth cut into squares or whatever shape that make a nice connected pattern and then stitched together. The quilt could be random pieces that is not related to each other. In most recent years and more common cases, a quilt is made of different pieces of patches that are connected and laid out in a special way to tell a story. Not only does it portray a story that is put together in a certain sequence, but it also stiches the pieces of the quilt into a nice and complete narrative. A story that one can understand just by looking at the quilt spread and unfolded. Much like the making of a quilt that has a story to tell, a Product Digital Quilt will tell the story of a product. The Digital Product Quilt replaces the conventional way of telling a product story. The traditional product story is a method that is serially connecting multiple product life cycle silos together
Hamada, Mohamed Y.Rabelo, Luis
Regarding the development of an aircraft assembly process, this paper will illustrate the intelligent decision and policies of the aircraft assembly process based on technician experience. A model of the knowledge management system of the aircraft assembly process is developed to avoid the complexity of the entire aircraft or aircraft product assembly process. Firstly, According to the characteristics of the knowledge management system of the aircraft assembly process, the aircraft assembly process has been discussed to realize the decision of the aircraft assembly process. Secondly, intelligent decision-making in the aircraft assembly process has been established based on the knowledge management system and aircraft assembly process library that is oriented to the assembly process requirements employing an assembly process reasoning method. Finally, the intelligent decision policies of the aircraft assembly process are based on tacit knowledge, which is applied to the decision-making
Miah, Md HelalZhang, Jianhua
The fundamental characteristic of aircraft assembly is assembly measurement accuracy. A single digital measurement device can meet the requirements of an analytical and small surface. But a single digital measurement device cannot meet the measurement requirements for synthetic and large surfaces, such as fuselage panel components. This research aims to establish a combined measurement method to improve the measurement quality and extend the measurement area. The method demonstrated the combined measurement method utilizing a combination of the laser tracker and the articulated arm measuring machine. In this research, the combined measurement system is constructed based on the complexity and large size of the fuselage panel. The articulated arm measuring machine is used to scan the surface of the panel components accurately and the coordinate conversion of the common points measured by the laser tracker to realize the shape of the aircraft fuselage panel. Then the measurement process
Miah, Md HelalZhang, Jianhua
BMW's Munich factory remains the fertile root of a century of manufacturing, including its first R32 motorcycle in 1923. At the Munich plant - flanked by the engine-shaped “four-cylinder” headquarters tower and futuristic BMW Welt museum and customer-delivery center - BMW recently showed media its reimagined “iFactory.” This lean, green and digitized environment can build ICE, hybrid, electric or even hydrogen fuel-cell models on a single assembly line. That master plan includes a car and battery factory in Debrecen, Hungary, that BMW claims will be the industry's first CO2-emissions-free plant in 2025, fed entirely by photovoltaic or other renewable electricity
Ulrich, Lawrence
NASA Langley Research Center has an improved method for making composite structures. Industrial composite manufacturing is primarily accomplished through three methods: co-cure, co-bond, and secondary bond processes. Co-cure produces predictable structures and joint properties but is costly and challenging to implement on large, complex structures. Co-bond and secondary bond processes have greater applicability to complex structures but produce unpredictable material interfaces and properties. The AERoBOND technology presents a method for manufacturing composites at scale with the reliability of co-cure in a bonded assembly process
The scope of this document is related to the particular needs of oxygen equipment with regards to packaging and transportation. The document provides guidance for handling chemical, gaseous and liquid oxygen equipment. It summarizes national and international regulations to be taken into account for transportation on land, sea and air and provides information on classification of hazardous material. The aim of this document is to summarize information on packaging and transportation of oxygen equipment. Statements and references to regulations cited herein are for information only and should not be considered as interpretation of a law. Processes to maintain cleanliness of components and subassemblies during processing and assembly or storage of work-in-progress are outside the scope of this document. Guidance on this can be obtained from ARP1176. Rules for transportation and shipment do not cover oxygen equipment installed in an interior monument, e.g., galley unit or in a fuselage
A-10 Aircraft Oxygen Equipment Committee
Using the Box Behnken experimental design, this research work gives a thorough mathematical model for predicting the effects of drilling parameters on the delamination factor during the drilling of CFRP/Al stacked composites. These composites are commonly utilized in aerospace applications and are frequently subjected to drilling for assembling purpose. The goal of this study is to predict the drilling parameters like drill type, drill diameter, feed rate and spindle speedthat affect the amount of delamination which occurs when drilling such composites. During the drilling operation, damage was noticed on the surface of the fabricated composite laminates. The experiments were conducted according to the Box Behnken experimental design and delamination response is measured by using an image processing software. It is concluded that among all the parameters, the feed rate influences more on the delamination factor
KALA, K.LAKSHMIRao, K. Prahlada
The world is moving from a manual workforce to a collaborative workforce in industrial production systems where humans and robots work together making the manufacturing process harmonious. Humans consist of characteristics like flexibility, adaptability, decision-making skills, and creativity while strength, endurance, speed, and accuracy are from robots. A combined workforce of a human and a robot provides more efficiency, flexibility, and increment in production. This paper compares a manual assembly and a collaborative assembly of ten flange assemblies. The assembly defined here is the joining of a circular cover plate and a flange using four bolts and nuts. A voice-assisted system is incorporated into the collaborative robot which picks the necessary assembly parts when prompted thus boosting the performance. The study begins by completing ten flange assemblies by a single person and noting the outcomes after completion of assembly. The time taken and the elemental motions are the
S, AdithyanRobin, AlfroSadique, AnwarP P, Lalu
Additive manufacturing (AM) technologies can produce lighter parts; reduce manual assembly processes; reduce the number of production steps; shorten the production cycle; significantly reduce material consumption; enable the production of prostheses, implants, and artificial organs; and produce end-user products since it is used in many sectors for many reasons; it has also started to be used widely, especially in the field of aerospace. In this study, polylactic acid (PLA) was preferred for the antenna substrate because it is environmentally friendly, easy to recycle, provides convenience in production design with a three-dimensional (3D) printer, and is less expensive compared to other available materials. Copper (Cu) tape and graphene filament were employed for the antenna patch component due to their benefits. The comprehensive comparative analysis between a full-wave model and a 3D-printed prototype of the antenna via the CST Microwave Studio program was demonstrated here. The
Avşar Aydın, EmineBiçer, Mustafa BerkanMert, Mehmet ErmanÖzgür, CeylaDoğru Mert, Başak
SAE J2461 specifies the recommended practices of a Vehicle Electronics Programming Stations (VEPS) architecture.in a Win32® environment. This system specification, SAE J2461, was a revision of the requirements for Vehicle Electronics Programming Stations (VEPS) set forth in SAE J2214, Vehicle Electronics Programming Stations (VEPS) System Specification for Programming Components at OEM Assembly Plants (Cancelled Jun 2004). The J2214 standard has been cancelled indicating that it is no longer needed or relevant
Truck and Bus Control and Communications Network Committee
As the world is moving from a manual workforce to a robot-based workforce, there is a huge scope for improved methods to make production lines more efficient. In this work, an effort is made to implement human-robot collaboration into an industrial process and is demonstrated with a flange assembly-line model. This paper explains how the Yolov4 algorithm was improved and fine-tuned to meet the requirements. A customized workspace was designed and manufactured to make the components more accessible. Different types of grippers were compared and the simplest and most efficient was then selected. Camera selection and calibration were done to get the RGB coordinates and the depth values which were finally converted into the robot's coordinate frame. The coordinates are then fed as the end goal position for the end effector to which the robot plans its motion and then executes. The paper also explains how the model responds to voice commands using the Google API to convert audio messages to
Seby, HarrisonSaju George, AlbinSadique, AnwarP P, Lalu
This SAE Aerospace Recommended Practice (ARP) provides processes for achieving the required cleanliness standards during the fabrication, assembly, and functional test of aircraft hydraulic systems. It covers exclusion and removal of solid and liquid contaminants from tubing during manufacture and final assembly, flushing of the installed system, and final checks to ensure cleanliness requirements are met
A-6A2 Military Aircraft Committee
For an enterprise, product quality is the foundation of its further development. Therefore, how to detect the quality of the products produced by the assembly line and accurately identify the problematic parts has become an increasingly concerned issue for enterprises. In this paper, we propose a novel quality detection model combining the latest YOLOv5 model and convolutional neural network, which can further improve the recognition precision and accuracy of YOLOv5 on the basis of its lightweight and high recognition efficiency. The proposed model can meet the needs of complex quality problems that are difficult to detect directly in assembly-line products. In the experiment, our model can detect the automotive dashboard and judge whether the cable buckle is connected in place. The accuracy of each buckle in the picture being correctly detected is more than 98%, the classification accuracy is also expected to reach 98
Luo, ErpaiZeng, ZimuDu, JiatongChen,, ZhuoBai,, YulongHuang,, YanjunChen, Hong
Contrary to popular opinion, Henry Ford didn’t invent the automotive assembly line. That was Ransom Olds of Oldsmobile fame, who reportedly patented his novel manufacturing approach in 1901. Twelve years later, Ford simply took Olds’ good idea and made it better. Much better, it seems. Rather than using a stationary line like Oldsmobile, the Ford Motor Company founder added a moving conveyor, thereby reducing worker fatigue while drastically increasing production throughput. The concept stuck, and more than a century later, the moving assembly line remains an integral piece of most automobile manufacturing
This specification covers performance testing at all phases of development, production, and field analysis of electrical terminals, connectors, and components that constitute the electrical connection systems in road vehicle applications that are: low voltage (0 to 20 VDC) or Coaxial. Incomplete (mechanical) specifications for jacketed twisted pair connectors are also provided. These procedures are only applicable to terminals used for In-Line, Header, and Device Connector systems. They are not applicable to Edge Board connector systems, twist-lock connector systems, >20 VAC or DC, or to eyelet terminals. No electrical connector, terminal, or related component may be represented as having met USCAR specifications unless conformance to all applicable requirements of this specification have been verified and documented. All required verification and documentation must be done by the supplier of the part or parts. If testing is performed by another source, it does not relieve the primary
USCAR
This SAE Recommended Practice covers the design and application of primary on-board wiring distribution system harnessing for surface vehicles. This document is intended for single phase nominal 120 VAC circuits that provide power to truck sleeper cab hotel loads so that they may operate with the main propulsion engine turned off. The power supply comes from alternative sources such as land-based grid power, DC-AC inverters and auxiliary power generators. The circuits may also provide power to improve vehicle performance through charging batteries or operating cold-weather starting aids
Truck and Bus Electrical Systems Committee
Recycling channels for foam materials, especially mattress foams, are set up. The foams are generally crushed into flakes and then assembled resulting in heterogeneous materials. These materials are more valuable if their properties are controlled. This work focuses on their acoustical properties. First, the properties of initial foams have to be estimated and the assembling process has to be analyzed in order to model the acoustic behavior of the reconstructed heterogeneous materials. The foams flakes are assembled with a binder and compressed during the manufacturing process. This work presents the methodology set up to predict the sound absorption of such heterogeneous materials based on recycled foams, from the estimation of the raw material properties to the final assembly. First, a large number of foams were measured in order to distinguish categories of materials. The data is stored in a database management software in order to perform some statistical analysis. Some typical raw
Chevillotte, FabienGontier, MathieuRomeyns, BarbaraMarchetti, Fabien
Lightweight structures and designs have been widely used in a number of engineered structures due to ecological and environmental aspects. Nonetheless, lightweight structures typically experience a reduced noise and vibration reduction performance as a consequence of their increased stiffness-to-mass-ratio. To enhance it, novel low mass and compact countermeasures are often sought to address the challenges of achieving not only a good Noise, Vibrations and Harshness (NVH) reduction performance but also maintaining a lightweight design. Recently, locally resonant metamaterials have emerged and shown potential as a lightweight noise and vibration solution with a superior performance in tunable frequency ranges, known as stop bands i.e. frequency regions where free wave propagation is not allowed. These can be achieved by assembling resonant elements that are tuned to the targeted frequency range onto a host structure. In this paper, the design of a locally resonant metamaterial to
Alves Pires, FelipeWandel, MartinThomas, ChristianDeckers, ElkeDesmet, WimClaeys, Claus
This specification covers a chloroprene rubber (CR) that can be used to manufacture product in the form of sheet, strip, tubing, extrusions, and molded shapes such as window channels, bumper pads, chafing strips, etc. For molded rings, compression seals, molded O-ring cord, and molded-in-place gaskets for aeronautical and aerospace applications, use the equivalent AMS7XXX specification
AMS CE Elastomers Committee
This specification covers a chloroprene (CR) rubber that can be used to manufacture product in the form of sheet, strip, tubing, extrusions, and molded shapes such as window channels, bumper pads, chafing strips, etc. For molded rings, compression seals, molded O-ring cord, and molded-in-place gaskets for aeronautical and aerospace applications, use the equivalent AMS7XXX specification
AMS CE Elastomers Committee
In-space and planetary surface assembly for human exploration is a challenging domain that encompasses various technological thrusts to support human missions. NASA is developing autonomous assembly agents to build structures like habitats and antennae on the Moon. These modular and reconfigurable Assembler robots will provide robotic assembly of structures, even in locations that prohibit constant human oversight and teleoperation
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