| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce heavy floor impact sound in which air propagation component is dominant. <P>SOLUTION: Short beams 13 of a floor structure 10 and beams 21 of a ceiling structure 20 are laid so as to cross at right angles. Thereby, a direction with small flexural rigidity of the floor structure 10 (weak axis direction) and a direction with small flexural rigidity of the ceiling structure (weak axis direction) cross at right angle. Namely, the direction with small flexural rigidity of the floor structure 10 coincides with a direction with large flexural rigidity of the ceiling structure 20. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
