Can cars improve NVH (noise, vibration, and harshness) using damping felt and sound insulation cotton?

In modern automotive design, NVH (Noise, Vibration, and Harshness) is a crucial indicator, directly impacting vehicle comfort and driving experience. To improve a car's NVH performance, manufacturers typically use various sound insulation materials, with damping felt and sound insulation cotton being the two most common choices. However, are these two sound insulation materials alone sufficient to effectively improve a car's NVH level? This article will explore this question in depth.

 Basic Concepts of NVH

NVH refers to the noise and vibration that passengers inside a vehicle may experience during driving. Noise sources can be categorized into external noise (such as wind noise, road noise, and engine noise) and internal noise (such as sounds from the car's audio system and air conditioning). Vibrations can originate from uneven road surfaces, engine vibrations, or vibrations from the vehicle's body structure. NVH control is not only crucial for driving comfort but also for vehicle quality and brand image. Therefore, improving a car's NVH performance is a common goal for every automaker.

 The principle and function of damping felt

Damping felt is a material specifically designed to reduce the propagation of vibrations, typically made of multi-layered composite materials. Its main function is to add a damping layer between the metal components of a car, thereby effectively absorbing vibration energy. The working principle of damping felt is to convert vibration energy into a small amount of heat energy through the plastic deformation of the material, thus reducing noise transmitted into the vehicle's interior.

In practical applications, damping felt is often applied to the vehicle's floor, door panels, and roof. By increasing the rigidity of the vehicle body, damping felt can significantly reduce vibrations caused by engine operation and tire-road contact, thereby improving the quietness of the vehicle interior.

Properties and applications of sound insulation cotton

Sound insulation cotton is a material used to isolate sound transmission, its main function being to reduce noise propagation. Unlike damping felt, sound insulation cotton is usually made of high-density foam or fiber materials, possessing excellent sound absorption properties. It effectively prevents external noise (such as traffic noise, wind noise, etc.) from entering the vehicle interior, while also absorbing sound generated by vibrations within the vehicle. The application of sound insulation cotton is quite widespread; in addition to common areas such as car doors, hoods, and trunks, many high-end models even incorporate sound insulation cotton under the roof and floor to achieve higher NVH performance.

 The combined use of damping felt and sound insulation cotton

In practical automotive NVH performance improvement, damping felt and sound insulation cotton are usually used in combination. The combination of the two can create a complementary effect: damping felt is responsible for absorbing vibration energy and reducing noise transmitted through the structure; while sound insulation cotton is responsible for isolating noise sources, further improving the quietness of the vehicle interior.

Undoubtedly, no single material can completely solve NVH problems. Just as a camera requires multiple lenses to focus, improving NVH in automobiles also requires coordination and comprehensive consideration from multiple aspects.

While materials are important, they are not everything when it comes to improving a car's NVH (noise, vibration, and harshness) performance. Here are some other equally crucial factors:

 1. Design Structure

The design and structure of a car directly affect its NVH performance. A well-designed body, such as optimizing the strength and rigidity of the chassis, can reduce vibration and noise at the source.

 2. Wheels and suspension system

Wheel design, tire selection, and suspension tuning all affect vibration transmission and noise generation. For example, choosing low-noise tires and a high-performance suspension system can significantly reduce road noise.

 3. Engine and transmission system

The engine's operating mode, the design of the engine mounts, and the precision of the transmission system also affect NVH performance. Enhancing the vibration isolation performance of the engine mounts can effectively reduce the vibration and noise generated by the engine.

 4. Driving habits

Driving habits also affect the NVH experience; rapid acceleration and hard braking can lead to greater vibration and noise. Therefore, cultivating good driving habits can also improve passenger comfort.

 in conclusion

In conclusion, improving a car's NVH performance cannot be achieved simply by using damping felt and sound insulation cotton. While these two materials play a crucial role in enhancing a car's quietness and comfort, truly comprehensive NVH improvement requires a combination of a well-designed structure, excellent material selection and matching, and even cultivating good driving habits. Therefore, when purchasing a vehicle, consumers should not only pay attention to its appearance and performance but also its NVH performance. Manufacturers, in developing new models, should also consider NVH design from all angles to enhance the overall quality and user experience of the final product.