Simplified Rocking Model of Unanchored Cylindrical Tank Including Baseplate Uplift and Cross Sectional Deformation of Tank Shell due to Seismic Load
Simplified Rocking Model of Unanchored Cylindrical Tank Including Baseplate Uplift and Cross Sectional Deformation of Tank Shell due to Seismic Load
复制标题
无锚定圆柱形储罐的简化摇摆模型，包括地震荷载引起的底板隆起和罐壳横截面变形
DOI：
10.1115/pvp2015-45082
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
Nobuyuki Kobayashi; Toshiki Tashita; Sho Takizawa; Tomoyo Taniguchi
中科院分区：
文献类型：
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作者：
Yudai Yamasaki;Shigehiko Kaneko;Nobuyuki Kobayashi; Toshiki Tashita; Sho Takizawa; Tomoyo Taniguchi
本研究提出了一种关于无锚定圆柱形液体储罐摇摆行为的简化估计方法，该储罐的底板部分从其土基上隆起，并且由于水平地震载荷，其外壳板的圆形横截面变形。由于沿壳板底端的垂直反力分布，在水平地震荷载作用下产生抵抗倾覆力矩的抵抗力矩，当其底板部分隆起时，会偏离正弦曲线。由于底板局部隆起，在罐体板中产生比正弦波高次谐波的轴向力，从而在罐体板中引起面外变形。这一特性使沿壳体板底部的竖向位移重新分布，影响壳体板受压侧的屈曲强度以及圆柱壳体板与底板连接处的升起侧的弯曲强度。考虑到这种摇摆行为，作用在壳板底部的垂直反力分布用傅里叶级数展开，并通过壳膜理论对傅里叶级数的每个系数导出壳板的面外变形。将通过本方法计算的储罐变形的数值结果与通过商业有限元代码获得的数值结果进行比较。
This study presents a simplified estimation method on the rocking behavior of the unanchored cylindrical liquid storage tank of which baseplate uplifts partially from its soil foundation and of which shell plate distorts its circular cross-section due to the horizontal seismic loads. Since the vertical reaction force distribution along the bottom end of shell plate, which yields resistant moment against the overturning moment due to the horizontal seismic load, deflects from sinusoidal when its baseplate uplifts partially. The out-of-plane deformation is induced in the shell plate of tank due to the axial force in the shell plate of higher harmonic number than the sinusoidal mode because of the partially uplifting of the base plate. This feature brings the vertical displacement along the bottom of shell plate redistribution, and it affects the buckling strength at the compression side of the shell plate and the bending strength at the uplifting side of the joint between the cylindrical shell plate and the baseplate. To take such a rocking behavior into account, the vertical reaction force distribution acting on the bottom of the shell plate is expanded with Fourier series and the out-of-plane deformation of shell plate is derived by the membrane theory of shell for each coefficient of Fourier series. Numerical results of tank deformations calculated by the present method are compared with those obtained by a commercial FEM code.