LNG储罐混凝土外罐环向预应力筋的张拉顺序

Tension sequence of circular prestressing reinforcing steel bar in concrete shell of LNG storage tank

以某工程50 000m3大型LNG储罐(液化天然气储罐)为例,利用ANSYS有限元软件对其进行模拟实验,对LNG储罐外罐预应力筋自上向下和自下向上2种张拉顺序进行数值模拟,得到不同张拉顺序下外罐混凝土应力、位移及其变化规律.结果表明:张拉过程中,自上向下张拉时混凝土的应力低于自下向上张拉的;应变基本相等,变化规律也相同.因此,在只考虑应力、位移的条件下,自上向下张拉方案要优于自下向上张拉方案.

This paper takes a 50 000 m3 LNG storage tank as an example, according to the constitutive relation of concrete and steel, test simulation with finite element software ANSYS, we can simulate the tension to the outer wall of LNG tanks by the bottom-top tension and top-bottom tensions. The outer wall’s stress, displacement value and the change rules under tension different order were obtained. Compared with the stress and displacement, the top-bottom tension’s stress is lower than the bottom-top’s. But their strain is equal, and their changing trends are similar. Thus considering stress and displacement value, the top-bottom tension is superior to the bottom-top tension.