木質ハイブリッド梁床モデルの鉛直振動特性に関する実験的研究

Abstract

The purpose of this study is to investigate the vertical dynamic charasteristics of two sorts of hybrid wooden floors. The wooden floor is a 6.5m-long-span and 1.0m-wide and consisted of two 120mm wide and 300mm deep laminated wood timbers with 21mm-thick plywood sub-floor. The hybrid concrete-wooden floor has 60mm-thick concrete slab connected by lagscrews onto the wooden floor and the hybrid ALC(Autocraved Lightweight Concrete)-wooden floor has ALC pannels fastened by wood screws onto the wooden floor. The test results indicate, i) The measured first natural frequencies of hybrid wooden floors coincide with those calculated according to the vibration theory for bending continuous model with the bending stiffness and the weight (the sum of dead-load and furniture-load except the human-load) of the hybrid wooden floor, ii) As the rigidity of the joint of concrete and the wooden floor is small, the frictional force between concrete and the wooden floor is not negligible in the bending stiffness, but hardly gives influence on the damping factor, iii) The damping factor at first natural frequency increases in proportion to the rate of human-load over the weight of the hybrid wooden floor.