Browse Topic: Center of gravity (CG)
A case study of an application of Shape optimization techniques in the design of a mass simulator has been presented. A simple mass Simulator is to be designed as a replacement for a Telescope Baffle Mass for testing purposes. The simulator is made of simple plate structures like flat plates and cylindrical plates joined together. The overall mass, location of center of gravity and first few modes of the simulator need to be close to the Telescope Baffle, it is replacing. This ensures that the Simulator is a good replacement for the Telescope Baffle both in statics and dynamics performance. Shape Optimization techniques using approximate direct linearization method of MSC/Nastran software have been used to fine-tune the baseline Simulator design to achieve target properties of mass, cg, frequencies, etc.
Automotive driveline imbalance is a result of rotating components or assemblies being manufactured with their centers of mass not being coincident with their centers of rotation. For vehicle mass production, an end-of-line (EOL) driveline balancing process may be required, depending on vehicle sensitivity and component control costing. In this investigation, the process and facility design for an EOL automotive driveline balancing process is outlined, including important considerations in the measurement configuration of the balancing facility. Initial results from prototype vehicle testing with conventional influence balancing techniques, based on commercially available equipment, are given. The role of the influence coefficient in the balancing process and of car-to-car variability in the influence coefficient were investigated. An equation for the influence coefficient was derived, providing an improved understanding of the nature of the influence coefficient, along with sources of
This analysis applies to crane types as covered by ASME B30.5.
The objective of this work is to capture the final deformed shape of a vehicle after a rollover caused by a corkscrew event (ramp). With this study, it will be possible to understand the vehicle structural behavior during this event and be able to improve the vehicle safety in this specific condition. For this proposal, it will be presented a virtual methodology using available commercial CAE tools and perform a crashworthiness analysis of the desired event. The first step is to capture the dynamic event through a Multibody analysis that represents the interaction among the vehicle tire, suspension components (Springs, Dampers, Jounce Bumper, Bushings, Stabilizer Bar etc.), vehicle structural stiffness, mass, center of gravity and inertias when exposed to a corkscrew standard ramp, that initiates the rollover event. This methodology will represent with fidelity all dynamic aspects of rollover event before the vehicle touches the ground. At this point, comparison of the analysis
This SAE Aerospace Standard specifies the dimensional, design criteria, fabrication, performance, operational, environmental, and testing requirements for interline pallets requiring airworthiness approval for loading onto civil transport aircraft equipped with NAS3610/AS36100 restraint systems and using pallet nets meeting the requirements of AS1492. Type II/2 covers NAS3610/AS36100 code sizes. Type III pallets have been removed from this SAE Aerospace Standard revision.
This document establishes dimensional, structural, and environmental requirements for Type II/2 interline pallet nets. Type II/2 covers NAS3610/AS36100 code sizes.
This code is intended for commercial vehicles over 4500 kg (10 000 lb) with brake systems having typical service pressure ranges 0 to 14.1 mPa (0 to 2050 psi) hydraulic or 0 to 830 kPa (0 to 130 psi) air and is not directly applicable to vehicles with other systems. Air over hydraulic systems are to be tested as air systems.
The powertrain mount is an important component, which reduces the vibrations generated from the powertrain. Vibration isolation is achieved with help of modal separation by predicting the kinetic energy fraction (KEF) and natural frequency (NF) at each mode. The soft mounts reduce vibrations transferred from the engine to the chassis, but if stiffness is very low, the displacement of the mount will be high, and hence, the lifetime of the mount will be less. Vibration isolation using a powertrain mount is a compromise between the displacement of the mount, displacement of the center of gravity of the powertrain, KEF, and NF. In this paper knowledge-based engineering (KBE) application methodology is explained to initially find out the optimum values of mount parameters using permutation and the combination of mount stiffness, mount angle, and mount locations. Using these permutations and combinations, KEFs, NF, and the displacement of the center of gravity of the powertrain are found. At
This analysis applies to crane types as covered by ASME B30.5.
The purpose of this specification is to provide airplane operators and tow vehicle manufacturers with: a General design and operating requirements pertinent to test and evaluation of towbarless tow vehicles. Specific design requirements are provided in ARP4852 and ARP4853. b Test and evaluation requirements. The results of these test evaluations will determine if the loads induced by the tow vehicle will exceed the design loads of the nose gear, or are within the aircraft manufacturer’s limits so that they do not affect the certified safe limit of the nose gear. The results of these test evaluations will also determine if a stability problem may occur during pushback and/or maintenance towing operations with the tested airplane/tow vehicle combination. This document specifies general test requirements and a test evaluation procedure for towbarless tow vehicles (TLTV) intended for pushback and maintenance towing only. It is not meant for dispatch (operational) towing (see definitions in
Vehicle pull during braking can be defined as the deviation of vehicle travel from intended path of the vehicle by a margin of half a wheel track or more. It is a dynamic phenomenon with very complex inter-dependencies among the combined functioning of various aggregates such as steering system, suspension system, axles, and brakes. The problem is aggravated with shorter wheelbase & higher CG (Centre of Gravity) height, where the instantaneous load transfers are sudden and of relatively high magnitude which can lead to a combination of forces that are responsible for vehicle drifting or pulling to anyone side of centre-line travel. Vehicle with shorter wheelbases, high GVW and high CG heights are more prone to this unstable behaviour due to sudden change in dynamic forces acting on the tires while turning and braking. Although these vehicles have some disadvantages, they are required for important applications such as stage and intercity operations and hence cannot be stopped producing
This SAE Aerospace Recommended Practice (ARP) includes recommended ground flotation analysis methods for both paved and unpaved airfields with application to both commercial and military aircraft.
This SAE Aerospace Recommended Practice (ARP) covers the recommended criteria and performance requirements for the design and installation of land-based aircraft emergency and operational arresting hooks for use on runway arresting systems. Design criteria for fully operational hooks and for carrier-based aircraft hook installations are contained in specification MIL-A-18717.
The vehicle dynamics terminology presented herein pertains to passenger cars and light trucks with two axles and to those vehicles pulling single-axle trailers. The terminology presents symbols and definitions covering the following subjects: axis systems, vehicle bodies, suspension and steering systems, brakes, tires and wheels, operating states and modes, control and disturbance inputs, vehicle responses, and vehicle characterizing descriptors. The scope does not include terms relating to the human perception of vehicle response.
While designing a self-balancing two-wheeled robotic vehicle, accurate high-speed measurement of angular rotation is a key requirement. Furthermore, the minimization of component weight and size is an equally vital consideration. Engineering students at Tokyo Denki University found the answer in the RM08 rotary magnetic encoder, from Renishaw’s associate company, RLS.
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