Abstract
This report presents the results of the experiment of unrestrained reinforced concrete panels under static and dynamic increasing shear load. These experiment are consist of four load method; (a) increasing static load, (b) increasing dynamic load, (c) reverse increasing static load after cracks and (d) reverse increasing dynamic load after cracks. Dynamic load is half amplitude vibration of sixty cycle in a minute. Static loading, (a) and (c) were tested for comparision to examine the effect of the dynamic load. The results were sumarized as follows; (1) The differences between crack and ultimate strength under dynamic load and those under static are not much. It is said to be same in the case of the normal and reverse load. (2) Plastic expansive ratio of the unrestrained panels is about 1.8 and is hisher than these of reinforced concrete walls restrained by frame. (3) The coefficients of plasticity of panel after cracks under normal load is coincide with those under reverse except the larly time. As experimental equation of static coefficient of plasticity, we obtained β_s=0.25(R×10^3)^<-1> and as these of dynamic one, β_D=0.44(R×10^3)^<-0.6>
