Estimation of drift limits for different seismic damage states of RC frame staging in elevated water tanks using Park and Ang damage index

Damage to elevated water tanks in past earthquakes can be attributed to the poor performance of their supporting frame staging. In order to ascertain the performance of these elevated water tanks, it is crucial to categorize the damage in quantifiable damage states. Among various parameters to quantify the damage states, the top drift of frame staging can be conveniently correlated to the different damage levels. In literature, drift limits corresponding to different damage states of the frame staging of the elevated water tank are not available. In the present study, drift limits for RC frame staging in elevated water tanks corresponding to different seismic damage states have been proposed. Various damage states of the elevated water tank have been determined using the Park and Ang damage index. The Park and Ang damage index utilizes results of both pushover analysis and incremental dynamic analysis. Twelve models of elevated water tanks have been developed considering variation in staging height and tank capacity. Incremental dynamic analysis has been performed using the suite of twelve actual earthquake ground motions. Based on the regression analysis between damage indexes and drift, limiting drift values for each damage state are proposed.

三维水箱运动控制系统的研制

三维水箱测量系统是医用直线加速器和X刀的质量保证(QA)和质量控制(QC)重要仪器[1]。为了提高三维水箱测量系统的测量精度和稳定性,保证放射性治疗过程的安全性和可靠性,介绍了一套运用虚拟仪器技术研制的应用在三维水箱测量系统中的实时的三维运动控制系统,描述了系统的整体结构和软件设计。

基于POM的物质输运方程数值格式研究

在三维海洋模式POM基础上建立水质模型,采用中心差分格式、迎风格式以及Smolarkiewicz迎风格式离散物质输运方程。以三维理想水槽中连续源排放的浓度场预测为例,分析3种离散格式求解所得的浓度场。结果表明,3种格式的数值解与解析解的偏差均小于20%。中心差分格式会引起解的震荡,导致物质的反向输移,出现浓度负值。迎风格式能够保证浓度的正值,但该格式带来的数值耗散导致数值解与解析解偏离较大。Smolark-iewicz迎风格式在普通迎风格式基础上引入抗扩散流速,经多次叠代,能有效降低计算中的数值耗散,提高了计算精度。