高宽比对剪切型配筋砌块砌体剪力墙耗能能力的影响

为了研究高宽比对配筋砌块砌体剪力墙耗能能力的影响，确定墙体的耗能参数。利用6片高宽比H/h为1.57、1.14和0.71的足尺全灌芯配筋砌块砌体剪力墙拟静力试验，通过计算墙体的耗散能（累积和单圈）、等效粘滞阻尼比ζ_eq、能量耗散系数ψ和功比指数I_w四个参数，来分析发生剪切型破坏模式墙体的耗能能力。研究结果表明:H/h对墙体的耗能能力影响较大，随着墙体变形的增大，H/h越小墙体的耗散能增长越迅速，墙体的延性越差；当H/h=1.14时，能量耗散系数ψ较低，等效粘滞阻尼比ζ_eq较小，约为7%~10%，墙体的耗能能力较差；当H/h=0.71时，ψ较高，ζ_eq较大，约为14%~15%，墙体的耗能能力较好；随着位移的增大，功比指数I_w逐渐增大，当位移较小时I_w几乎呈线性增长，当位移较大时I_w呈非线性增长，H/h=1.14墙体的I_w增长相对缓慢。可见:对于发生剪切型破坏模式的配筋砌块砌体剪力墙，H/h接近1时耗能能力较差，在工程中尽量避免采用。

Effect of aspect ratio on energy dissipation capacity of reinforced-block masonry shear walls with shear-dominated failure mode

The energy dissipation parameters are determined for studying the influence of the aspect ratio on the energy dissipation capacity of reinforced-block masonry shear walls. Six full-scale fully grouted sample models with the aspect ratio H/h of 1.57, 1.14 and 0.71 are tested subjected to the low cyclic reversed lateral loads. The energy dissipation capacity of the walls with the shear-dominated failure mode is analyzed through calculating four parameters including dissipated energy (accumulation and single circle), equivalent viscous damping ratio ζ_eq, energy dissipation coefficient ψ and power ratio index I_w. The results indicate that H/h has a great influence on the energy dissipation capacity of the wall. As the deformation of the wall increases, the smaller the H/h is, the faster the dissipated energy of the wall grows, and the worse the ductility of the wall becomes.When H/h=1.14, the energy dissipation coefficient ψ is low with a small equivalent viscous damping ratio ζ_eqof about 7%-10%, and the energy dissipation capacity of the wall is poor. When H/h=0.71, ψ is higher with a larger ζ_eq of about 14%-15%, and the energy dissipation capacity of the wall is better. As the displacement increases, the power ratio index I_w gradually increases. I_w shows a linear increasing trend when the displacement is small, however,I_w increases nonlinearly when the displacement is relatively large. When H/h=1.14, I_w of the wall increases relatively slowly.It is concluded that the energy dissipation capacity of the reinforced-block masonry shear walls with the shear-dominated failure modeis poor when H/h is close to 1, which is not recommended for engineering applications.