Test And Study On The Effect Of Enclosed Sand Structure On The Damping Property Of Concre

Damp is a parameter that reflects the energy dissipation during structural systemvibration analysis, and also an important factor affecting structural vibration responseand earthquake reaction. It is necessary to study the damping performance of concretein enclosed sand structure, making foundation for studying damping mechanisms ofconcrete, doing favor for designer in damping design, and offering basis for designinga new damping structure of concrete.Different kinds of common concrete, such as C10,C15,C20,C25,C30 wereconfected using gravel, then they were made for different types of enclosed sandstructure concrete, by filling with materials of different filling rate and filled graindiameter in preparative hole of diameter of 32 mm. The relations among dampingratio and parameters as resistance to compression, filling rate, particle diameter, andresponse frequency were achieved by free vibration with hanging cuboid fordetermining these parameters of enclosed sand structure concrete. It made a basis forthe relation between enclosed sand structure and damping ratio.The results showed that resistance to compression, filling rate, particle diameter,and response frequency were influencing factors for damping ratio of enclosed sandstructure concrete. The filling rate and particle diameter affected more.The conclusions were showed as follows:1 The damping ratio of enclosed sand structure concrete increased with thedecrease of resistance to compression, and increased with the increase of filling rate.It gained more by 25% than free at filling rate of 100%. The damping ratio of thatincreased with particle diameter and then decreased. And it gained more by 40% thanfree at particle diameter of 5 mm.2 The influences of particle diameter to damping ratio were more obvious than that of filling rate.3 To different inspiring areas, the damping ratio changed as waves with theincrease of response frequency, and the peak value decrease with the increase of that.Theoretic analyses were made finally, including the reasons of resistance tocompression to damping ratio, the mechanisms of filling rate and particle diameter toit.