FIELD: acoustics.
SUBSTANCE: invention relates to industrial acoustics and can be used to reduce the noise of the drive of machines, for the lining of industrial premises and in other sound-absorbing structures. Stand for testing acoustic characteristics of sound absorbing elements in industrial premises comprises a test object that is installed freely on the floor in a premises, and at five measurement points along the perimeter of the test object at a distance of 1 m from its overall dimensions, acoustic microphones are installed from a set of acoustic equipment that meets the requirements for measuring systems. Number of measurement points is five, and the number of measurements at each point is three. After measurements, the noise characteristics of the object are calculated according to certain mathematical expressions. Investigated lining is made in the form of rigid and perforated walls, between which there is a multilayer sound-absorbing element made in the form of two layers: one of which, adjacent to the rigid wall, is sound-absorbing, and the other, adjacent to the perforated wall, is made with perforation from a sound reflecting material of a complex profile consisting of uniformly distributed hollow tetrahedrons. As a sound-reflecting material, a material based on aluminum-containing alloys is used, followed by filling with titanium hydride or air with a material density of 60÷80 kg/m3, or a material based on a magnesia binder with reinforcing fiberglass or glass-fiber mat.
EFFECT: technical result consists in increasing the efficiency of sound attenuation and the reliability of the structure as a whole.
1 cl, 3 tbl, 6 dwg
