Human hearing, with its active transducers, attention process and remarkable signal-processing abilities, challenges the transportation-product sound quality engineer to measure accordingly and has cl....
There are several methods to capture and visualize the acoustic properties in the vicinity of an object. This article considers scanning PU probe based sound intensity and particle velocity measuremen....
This paper presents a test methodology to determine the physical properties of stiffness and damping for powertrain rotating components using a free-free torsional frequency response measurement. The ....
When testing dynamic structures, it is important to note that the dynamic system in question may be submerged into a fluid during operation and to properly test the structure under the same condition ....
Many applications in acoustics, such as transfer path analysis and synthesis (the well-known tools for troubleshooting and sound design of vehicle interior or exterior noise), require the measurement ....
Advanced engine test methods incorporate several different sensing and signal processing techniques for identifying and locating manufacturing or assembly defects of an engine. A successful engine tes....
A powered seat adjuster is a complex mass-produced assembly that is heavily optimized for low cost and light weight. The consequence is an inevitable degree of uncontrolled variation in components, su....
Durability testing of engine mounted components is often performed using sine testing. To ensure that all resonance frequencies are excited, swept sine is used across the frequency range of excitation....
Microphone arrays used in vehicle acoustics are mainly designed for fast setup and basic evaluation (e.g. using delay-and-sum beamforming) resulting in a restriction to free field environments. Applic....
The NVH (Noise Vibration Harshness) behavior of modern vehicles becomes more and more important - especially in terms of new powertrain concepts, like in hybrid electric or full electric vehicles. The....
Pass by noise is a complex test that requires meeting several different standards with regard to the physical track layout, measurement systems, data acquisition, triggering, processing and analysis. ....
Several methods have been established to measure the normal incidence transmission loss of noise control materials using the standing wave tube. In the automotive NVH field, multi-layered systems are ....
Electrodynamic shakers or exciters are commonly used in experimental modal analysis. The practical aspects regarding the setup of the shakers, stingers and transducers are often the source of test dif....
It is very important to accurately measure rotation frequencies and fluctuations of rotating systems since they cause vibrations and noises, and since they sometimes indicate system malfunctions. Most....
Highly effective double-wall systems for automotive applications can often have over a 90 dB span in sound transmission loss values between low frequencies, where they are usually least effective and ....
Research into the estimation of diesel engine combustion metrics via non-intrusive means, typically referred to as “remote combustion sensing” has become an increasingly active area of combustion rese....
