997 resultados para Vehicle Body Pillars.


Relevância:

90.00% 90.00%

Publicador:

Resumo:

National Highway Traffic Safety Administration, Washington, D.C.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

National Highway Traffic Safety Administration, Washington, D.C.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

National Highway Traffic Safety Administration, Washington, D.C.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

National Highway Traffic Safety Administration, Office of Research and Development, Washington, D.C.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

National Highway Traffic Safety Administration, Office of Research and Development, Washington, D.C.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

A novel method of matching stiffness and continuous variable damping of an ECAS (electronically controlled air suspension) based on LQG (linear quadratic Gaussian) control was proposed to simultaneously improve the road-friendliness and ride comfort of a two-axle school bus. Taking account of the suspension nonlinearities and target-height-dependent variation in suspension characteristics, a stiffness model of the ECAS mounted on the drive axle of the bus was developed based on thermodynamics and the key parameters were obtained through field tests. By determining the proper range of the target height for the ECAS of the fully-loaded bus based on the design requirements of vehicle body bounce frequency, the control algorithm of the target suspension height (i.e., stiffness) was derived according to driving speed and road roughness. Taking account of the nonlinearities of a continuous variable semi-active damper, the damping force was obtained through the subtraction of the air spring force from the optimum integrated suspension force, which was calculated based on LQG control. Finally, a GA (genetic algorithm)-based matching method between stepped variable damping and stiffness was employed as a benchmark to evaluate the effectiveness of the LQG-based matching method. Simulation results indicate that compared with the GA-based matching method, both dynamic tire force and vehicle body vertical acceleration responses are markedly reduced around the vehicle body bounce frequency employing the LQG-based matching method, with peak values of the dynamic tire force PSD (power spectral density) decreased by 73.6%, 60.8% and 71.9% in the three cases, and corresponding reduction are 71.3%, 59.4% and 68.2% for the vehicle body vertical acceleration. A strong robustness to variation of driving speed and road roughness is also observed for the LQG-based matching method.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The Cambridge University's Gordon Laboratory, in collaboration with Fibertech and the Defence Science and Technology Laboratory in the UK, has developed a novel melt spun fiber bore called 'Fibrecore', fabricated entirely from stainless steel with thin faceplates. Fibrecore is typically manufactured by 5mm-long and 70μm thick stainless steel fibers, produced by a melt overflow process. Its entirely metallic construction allows spot welding and tungsten inert gas welding without difficulty. Fibrecore exhibits different energy absorption mechanisms such as core cushioning, core-faceplate delamination, and plastic faceplate deformation, often in a concertina-like fashion. Its low-cost, high structural efficiency and good energy absorption characteristics make it attractive for a range of commercial and military applications. Such applications being evaluated include vehicle body panels, exhaust system noise reduction, low cost filters, and lightweight physical protection. In addition to these characteristics, Fibrecore exhibits properties such as corrosion protection, vibrational damping, and thermal insulation, which also extend its applications.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Nutzfahrzeuge müssen oft durch sehr unebenes Gelände gefahren werden. In diesem Fall wird der Fahrer starken Vibrationen ausgesetzt, die von der Fahrzeugkarosserie durch die Sitzaufhängung auf ihn wirken. Um diese Schwingungen zu verringern, werden die Sitzaufhängungen in der Regel mit Feder-Dämpfer-Systemen ausgerüstet. Jedoch erreichen die passiven Systeme vor allem bei niederfrequenten Schwingungen ihre physikalischen Grenzen. Eine wesentliche Verbesserung des Sitzkomforts kann unter solchen Anregungsbedingungen nur mit einer aktiven Sitzaufhängung erreicht werden. In diesem Beitrag wird ein neuartiges aktives System für die Sitzaufhängung auf Basis von elektrorheologischen Flüssigkeiten vorgestellt. Außerdem werden die theoretischen Grundlagen für die Modellierung der beschriebenen aktiven Sitzaufhängung dargestellt. Anschließend werden die Simulationsergebnisse mit den Messergebnissen unter realen Betriebsbedingungen verglichen. Die Repräsentation der Ergebnisse mit Hilfe der im Bereich der Sitztechnik weit verbreiteten SEAT-Werten (Seat Effective Amplitude Transmissibility) zeigt das Potenzial des entwickelten Systems zur aktiven Reduktion der Schwingungsbelastung des Fahrers und ermöglicht seine objektive Bewertung.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

National Highway Traffic Safety Administration, Washington, D.C.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

National Highway Traffic Safety Administration, Washington, D.C.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

National Highway Traffic Safety Administration, Washington, D.C.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

National Highway Traffic Safety Administration, Office of Research and Development, Washington, D.C.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

National Highway Traffic Safety Administration, Washington, D.C.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Mode of access: Internet.