The compressive property and energy absorption ratio of foamed Al 7Si 0.45Mg alloy and the permeability of compressed foamed Al 7Si 0.45Mg alloy in air are studied. The coefficient of the sound absorption and the sound insulation of compressed foamed Al alloy in air are measured. The influence of original porosity of foamed alloy on the above mentioned properties is discussed.

Based on the analysis, a relevant mathematical model was then established, and the sound insulation properties of the glass bead-filled polyethylene composite were finally predicted.

Mainly discussed about the established of the business car model with the theory statistical energy analysis (SEA), in the noise control the sound insulation and absorption are selected with mechanical engineering optimization design. The results of simulations evidence that the selected noise control method is feasible.

The sound insulation performance of decoupling meterial is studied in this paper. The formula of input impedance,homology coefficient and insertion penalty of the decoupling material with multiple layer architecture is provided by using the method of transitive matrix.

In order to study the effect of the reinforced material in the composites on the sound insulation property of the soundproof composites,the fabric /PVC composites are prepared,using PVC resin which is usually used in soundproof materials as matrix,choosing the glass fabric,the PET fabric as reinforced materials.

Mainly discussed about the established of the business car model with the theory statistical energy analysis (SEA), in the noise control the sound insulation and absorption are selected with mechanical engineering optimization design. The results of simulations evidence that the selected noise control method is feasible.

The sound insulation performance of a light panel-stud partition is greatly affected by its construction details. Since the construction parameters are very complicated, it could hardly be predicted by calculation now if it is not impossible.After a series of experimental works in our sound insulation test facility, the following results are esteemed valuable for practice. (1) T. L. for steel stud partition is higher than wood stud by 4 dB in average. It is recommanded that the depth and spacing...

The sound insulation performance of a light panel-stud partition is greatly affected by its construction details. Since the construction parameters are very complicated, it could hardly be predicted by calculation now if it is not impossible.After a series of experimental works in our sound insulation test facility, the following results are esteemed valuable for practice. (1) T. L. for steel stud partition is higher than wood stud by 4 dB in average. It is recommanded that the depth and spacing of stud should not be less than 7 cm and 60 cm respectively. (2) Addition of the first extra leaf to a two-leaf panel partition would improve the T. L. by 5-6 dB, but for the another extra leaf only 2-4 dB. (3) Sound deadening fiber board strips between the stud and the panel on both side would reduce the sound bridge effect, and then an improvement of T. L. of 3-6 dB for steel stud partition is achieved, 6-9 dB for wood stud partition. (4) Acoustical fiber bat in cavity would improve the T. L. by 5 dB for steel stud partition, and 8 dB for wood stud partition. While only a small improvement, approximately 2 dB per leaf, could be gained by adding an extra leaf. (5)Since the effects of above measures are not simply additive, one might choose the propriety of construction carefully if a high T. L. partition is reqnired.

This article offers an objection to the traditional calculating method for the sound insulation of the single enclosure structure of ships, and probes the pending problems. Forty-five marine engines of different types are used in the calculation of the degree of sound insulation of steel plates with a thickness of 1-8mm; the influences of various noises of the spectrum on the effect of sound insulation are counted and analyzed; two practical formulas (shown by a single peak) for...

This article offers an objection to the traditional calculating method for the sound insulation of the single enclosure structure of ships, and probes the pending problems. Forty-five marine engines of different types are used in the calculation of the degree of sound insulation of steel plates with a thickness of 1-8mm; the influences of various noises of the spectrum on the effect of sound insulation are counted and analyzed; two practical formulas (shown by a single peak) for calculating the degree of sound insulation of structures are regressive, and these formulas are applicabel whether there is corresponding effect or not. A great many of the calculations indicate that the calculating formulas and the value TL_(500) in the reference [1] and [2] are responsible for a great error in the calculation of engineering design. It is proved that the calculatieg formulas presented in this article are also applicable to such materials as aluminium plates, plywood and glass. This article ends by illustrating the application of the formulas.

The plasma spraying techniques, which have been widely used in many products design, is a new kind of technology for hardening and protecting parts surface. But the environment pollution caused by the noise from the process of plasma spraying is a much concerned matter. The following results were obtained by measuring the spraying equipment and noise from the process of spraying. The noise produced by monomic work gas was quite different from the noise produced by diatomic work gas, the noise intensity were...

The plasma spraying techniques, which have been widely used in many products design, is a new kind of technology for hardening and protecting parts surface. But the environment pollution caused by the noise from the process of plasma spraying is a much concerned matter. The following results were obtained by measuring the spraying equipment and noise from the process of spraying. The noise produced by monomic work gas was quite different from the noise produced by diatomic work gas, the noise intensity were less affected by the changes of the work electric current and work air stream quantity. The frequency band of the plasma spraying noise is wider and high frequency noise is warmer. Based on the above results, the sound insulation should be considered as a principle aspects and the sound absorption as an auxiliary aspect in the design of noise control. The practical facts shows that if the suitable materials for sound insulation and sound absorption were chosen, it is possible to meet the requirement of noise standard under the condition of continuously normal work.