广州空压机匠心厂

声波传播过程中遇到铁路声屏障时，一部分被反射，一部分拉吸收，还有一部分被透射或绕射。声屏障通常至少有一层密实材料制成的隔声层，其目的是要保证透射声比绕射声低得多。例如低10分贝以上。这样，在理论分济和实用设计中，就可认为通过屏障的透射声可以忽略不计，只要考虑屏障边缘的绕射作用就行了。声屏障对直达声遮挡作用的大小，实际上就取决于绕射声的相对强弱。对于给定的直达声，设置声屏田后，在一定的距离范围内，绕射声的声级可以降至很低，即声屏障对直达声的遮挡作用很强。这种低声级的区域叫做窜影B，它类似于光线披不透明物体遮挡以后形成的阴影。只是由于声波波长远大于光波波长，声传播路径与光路直线传播的差别很大，因此声影区的边界一般不很明显。在声屏障边缘之外，由声源发出来的声波可以直线到达的区域叫做鳖B。从声影区到亮区之间有一段界限不很明显的过渡区。

In the course of sound propagation, when a railway noise barrier is encountered, some of it is reflected, partially absorbed, and partly transmitted or diffracted. A sound barrier usually has at least one sound insulating layer made of dense material, with the aim of ensuring that transmission is much lower than diffraction. For example, a low of 10 decibels or more. Thus, in the theoretical division and practical design, it can be considered that the transmission sound through the barrier can be neglected, so long as the diffraction action of the barrier edge is taken into consideration. The size of the sound barrier to direct sound blocking depends in fact on the relative intensity of the diffracted sound. For a given set of direct sound, sound field, in a certain range, the sound level of diffracted sound can be reduced to a very low, i.e. the sound barrier of direct sound shielding effect is very strong. This low level region is called shadow B, which is similar to the shadow formed by light opaque objects. Just because of the acoustic wave is much larger than the wavelength of light, sound and light propagation path of rectilinear propagation vary greatly, so the acoustic shadow boundary is generally not very obvious. Outside the edge of the noise barrier, the area where sound waves from the sound source can travel in a straight line is called the turtle B. There is a transition zone boundary is not obvious from the sound shadow zone to the bright region between.