建物免震用の高減衰積層ゴムに関する研究 : 第2報, 破断限界

抄録

This paper describes the results of breaking tests of high damping rubber bearings. The breaking .tests were carried out for 0.5 scale models of two types of rubber bearing which had the same shape but differed in rubber hardness. The full-scale rubber bearings were tested to investigate their hySteretic restoring force characteristics, which were mentioned in the 1st report. Biaxial tests by compression and shear showed that the breaking shear strains gradually decreased with increased compressive stresses. The breaking shear strains under various compressive stresses were larger than 600% for the low hardness type and larger than 400% for the high hardness type. These breaking strains are large enough for reliable seismic isolation of buildings. Biaxial tests by tension and shear revealed that the breaking tensile stresses and strains were decreased with increased shear strains, and that the rubber bearings had considerably hard stiffnesses in small tensile strains. For simple tension without shear, the tensile stiffnesses were about 1/3 of the compressive one for the low hardness type and about 1/4 for the high hardness type.