Shogo Mamada

Development of Rail Noise Isolating Material (RNIM)

Recently, there have been increasing requirements to control the rolling noise generated by the wheels and rails, but the conventional counter measures such as noise barriers have a big disadvantage in that their installations are very labor-intensive. Therefore, the authors have developed a new type of material, called rail noise isolating material (RNIM), which consists of two laminated layers, the inner one a foamed ethylene-—propylene rubber and the outer one vibration-damped steel. An impact test executed in a laboratory and some noise measurements executed on commercial lines have verified that RNIM is effective in reducing rolling noise.

Development of a System Using Piezoelectric Materials to Reduce the Interior Noise of a Railway Vehicle

With respect to the reduction of the interior noise of railway vehicles, most of the countermeasures taken have been mainly passive procedures based on the mass law. Although the application of “active noise control” to railway vehicles represents a challenge, only a few experimental tests were carried out so far. This paper proposes a system to reduce the interior noise using piezoelectric materials. The effectiveness of the system will become apparent through the evaluation of the proposed noise reduction system as applied to the ceiling panels under a pantograph of the hinkansen.