利用有限元软件ABAQUS对储罐不均匀沉降进行计算,得出储罐在不同工况下的结构响应,发现大沉降面积会导致应力分布出现显著差异。利用自主封装光纤光栅应变传感器开展了不同液位及不同沉降面积的沉降模拟试验,实现了储罐壁板和边缘板应力的动态监测,采用最小二乘多项式拟合试验数据,得到不同阶次的相关系数拟合曲线及4阶拟合曲线的一阶导数,发现了储罐罐壁及边缘板应力的变化符合高阶多项式曲线的变化趋势。结果表明,储罐液位高,引起罐壁、边缘板及角焊缝的应力变化大;不均匀沉降导致壁板上应力的变化并非为线性增加或减少。相同工况下,高液位时应力变化拐点的出现早于低液位时的,储罐变形大且变化快。

The uneven settlement of the storage tank is calculated by using the finite element software ABAQUS, and the structural response of the tank under different working conditions is obtained. It is found that the large settlement area will lead to significant differences in stress distribution. Through independent packaging of fiber grating strain sensors and carrying out settlement simulation experiments with different liquid levels and different settlement areas, the dynamic monitoring of the stress of the wall and edge plates of the experimental storage tank were realized, and the experimental data were fitted with least squares polynomials to obtain different order simulations. The fitting coefficient curve and the first derivative value of the fourth-order fitting curve are found to show that the stress of the tank wall and edge plate of the storage tank conforms to the change trend of the high-order polynomial curve. Comprehensive analysis shows that the high liquid level of the storage tank causes large changes in the stress of the tank wall, edge plates and fillet welds, and uneven settlement causes the stress changes on the wall plates to increase or decrease in a non-linear manner. Under the same working conditions, the inflection point of stress change at high liquid level appears earlier than that at low liquid level, and the tank deforms greatly and changes quickly.