Category Archives: Latest Automobile Technology

What Is NVH | NVH Noise | NVH Vibration | NVH Harshness | Noise And Vibration Theory | NVH Basics

Noise:

Noise is defined as any unpleasant or unexpected sound created by a vibrating object.

Vibration:

Vibration is defined as any objectionable repetitive motion of an object, back-and-forth or up-and-down.

Harshness:

Harshness is defined as an aggressive suspension feel or lack of “give” in response to a single input.

01-types of Noise of car-NVH noise-wind noise-road noise-engine noise-exhaust noise-acoustic waves

Noise and Vibration Theory:

A vibrating object normally produces sound, and that sound may be an annoying noise. In the case where a vibrating body is the direct source of noise (such as combustion causing the engine to vibrate), the vibrating body or source is easy to find. In other cases, the vibrating body may generate a small vibration only.This small vibration may cause a larger vibration or noise due to the vibrating body’s contact with other parts. When this happens, attention focuses on where the large vibration or noise occurs while the real source often escapes notice. An understanding of noise and vibration generation assists with the troubleshooting process. The development of a small noise into a larger noise begins when a vibration source (compelling force) generates a vibration. Resonance amplifies the vibration with other vehicle parts. The vibrating body (sound generating body) then receives transmission of the amplified vibration.

01-audible range of sound-pitch-intensity-sound-soundwaves-NVH noise-level

A sound wave’s cycle, period, frequency, and amplitude determine the physical qualities of the sound wave.

The physical qualities of sound are:

  • Audible range of sound
  • Pitch
  • Intensity

For sound to be heard, the resulting acoustic wave must have a range of 20 to 20,000 Hz, which is the audible range of sound for humans. While many vehicle noises are capable of being heard, some NVH noises are not in the audible range.

Durability Analysis | Application Of Durability Analysis In Automotive, Aerospace & Wind Turbines

Automotive

01-altair-NVH software-NVH test result of a car

  • Design more reliable transmissions, drivelines and axles
  • View the whole gearbox as an interacting and flexible system
  • Predict gear, bearing and shaft life-times in the design concept phase
  • Accurately and efficiently compare complex gearbox arrangements or concepts such as AMT, DCT, Hybrid and CVT
  • Reduce gearbox weight by using component strength
  • Minimize noise and vibration by influencing the transmission error
  • Identify the weak points in the whole system under realistic load conditions
  • Consider the impact of manufacturing tolerances in the concept design phase
  • Improve the bearing choice by unique accurate prediction of bearing behavior
  • Interact with dynamic solutions for your full vehicle design
  • Predict the affects of generators/e-engines on the gears and its components in your hybrid system

Wind turbine

01-wind turbine analysis-durability analysis of wings

  • Understand and benchmark operating load and extreme load scenarios
  • Design gearboxes to meet life-time targets
  • View the gearbox as one complete system, without the need for sectioning and sectional boundary conditions
  • Analyze the behavior of complex planetary systems within the whole system
  • Accurately predict loads, deflections and interactions of all components
  • Calculate detailed bearing behavior to identify excessive loads
  • Direct loads or reduce misalignments to improve the system quality
  • Predict load sharing in the fully flexible system instead of assuming load sharing factors
  • Reduce weight and cost without reducing component lifetime
  • Minimize noise pollution caused by transmission error

Aerospace

01-aerospace analysis of wings-frequency analysis

  • Improve reliability for critical parts
  • Reduce gearbox weight
  • Predict bearing behavior under extreme load and climate conditions
  • Optimize gearbox size

Off-highway

01-heavy duty engineering analysis-large gear analysis

  • Design heavy duty transmissions
  • Accurately represent multi-gear mesh situations
  • Optimize gearbox weight without compromising durability
  • Predict system behavior under misuse conditions
  • Compare different lubrication situations
  • Precisely define micro-geometries to avoid edge-loading of teeth under extreme load conditions
  • Consider split-torque system load

Industrial equipment

  • Design for improved reliability in process machinery, material handling, power take offs, speed reducers and production line equipment
  • Improve accuracy of high precision machinery by understanding and predicting system and component deflections
  • Reduce failures in gears and bearings due to precise prediction of misalignments

Consumer and office appliance

01-casting design-optimize weight-wasting material reduction

  • Optimize weight and size of power tools, food processors, washing machines, printers and photocopiers
  • Improve product quality by reducing unwanted deflections
  • Predict changes of working accuracy over a product’s life
  • Design casings that fulfill the requests for look and function simultaneously without wasting material
  • Consider new materials for new or existing product concepts
  • Create technical documentation for certification