SLOSHING AND DYNAMIC INTERACTION BETWEEN LIQUID AND FLOATING ROOF IN A STORAGE TANK UNDER SEISMIC EXCITATION

本文给出了地震激励下具有各向同性浮顶和单层浮顶的圆柱形储液罐晃动的解析解。本文在线性势流理论的框架内，精确地考虑了液体与浮顶的动力相互作用，并提出了一种基于有限元与解析解耦合的求解方法，用于处理由正交各向异性变厚度板组成的浮顶。为了验证理论方法的正确性，本文用一个小尺度水池模型进行了摇床试验，得出以下结论：（1）单层屋盖对降低波高的作用很小，屋盖位移与自由面高度相差不大。双层屋盖和加劲肋屋盖的主要刚体运动模态 ...更多信息 .内区的位移明显减小，而沿着罐壁的位移相对于自由液面高度变化不大。2)单层屋盖的动水压力在内甲板以下较低，沿浮筒底部较高，内甲板与外浮筒连接处产生较大的弯曲应力，与钢的屈服应力、双层屋面和肋板上的动水压力相比，加劲屋盖比单层屋盖的内层高，但弯曲应力仍远低于钢的屈服应力; 3）屋盖位移的解析解与振动台试验结果吻合较好，而单层式屋盖的内层则出现非线性双谐共振振荡。4)为了防止浮顶在2003年日本地震中的破坏，建议将单层浮顶改为双层浮顶或加劲肋浮顶。少

ANALYTICAL SOLUTIONS HAVE BEEN PRESENTED FOR THE SLOSHING IN A CYLINDRICAL LIQUID STORAGE TANK WITH A UNIFORM ISOTROPIC FLOATING ROOF AND A SINGLE-DECK TYPE FLOATING ROOF UNDER SEISMIC EXCITATION. DYNAMIC INTERACTION BETWEEN THE LIQUID AND THE FLOATING ROOF HAS BEEN TAKEN INTO ACCOUNT EXACTLY WITHIN THE FRAMEWORK OF LINEAR POTENTIAL THEORY A COMPUTATIONAL METHOD BASEN ON COUPLED FINITE ELEMEMT AND ANALYTICAL SOLUTIONS HAS ALSO BEEN PROPOSED TO DEAL WITH AFLOATING ROOF COMPOSED OF AN ORTHCYIROPIC PLATE OF VARIABLE THICKNESS. IN ORDER TO CONFIRM THE VALIDITY OF THE THEORETICAL APPROACH, SHAING TABLE TESTS HAVE BEEN PERFORMED USING A SMALL-SCALE TANK MODEL THE CONCLUSIONS ARISING FROM THE PRESENT STUDY CAN BE SUMMARIZED AS FOLLOWS : 1) THE EFFECT OF THE SINGLE-DECK TYPE ROOF ON REDUCING THE WAVE ELEVATION IS SO SMALL THAT THE ROOF DISPLACEMENT IS NOT SO DIFFERENT FROM THE FREE SURFACE ELEVATION. THE DOUBLE-DECK TYPE ROOF AND THE RIB-STIFFENED ROOF MOVE PREDOMINANTLY IN THE RIGID-BODY MODE … More . THE DISPLACEMENT IN AN INNER REGION IS REDUCED CONSIDERABLY, WHILE THE DISPLACEMENT ALONG THE TANK WAIL IS NOT SO CHANGED FROM THE FREE SURFACE ELEVATION. 2) THE HYDRODYNAMIC PRESSURE ON THE SINGLE-DECK TYPE ROOF IS RELATIVELY LOW UNDER THE INNER DECK, WHILE IT BECOMES RELATIVELY HIGH ALONG THE PONTOON BOTTOM LARGE BENDING STRESSES ARISE IN THE INNER DECK ALONG THE CONNECTION WITH THE OUTER PONTOON, WHICH IS COMPARATIVE IN MAGNITUDE ID THE YIELDING STRESS OF THE STEEL THE HYDRODYNAMIC PRESSURE ON THE DOUBLE-DECK-TYPE ROOF AND THE RIB-STIFFENED ROOF BECOMES HIGHER THAN THAT ON THE INNER DECK OF THE SINGLE-DECK TYPE ROOF, BUT THE BENDING STRESSES REMAIN WELL BELOW THE YIELDING STRESS OF THE STEEL 3) THE ANALYTICAL SOLUTIONS FOR THE ROOF DISPLACEMENT COINCIDE WELL WITH THOSE MEASURED BY THE SHAKING TABLE TESTS, WHILE NON-LINEAR BI-HARMONIC RESONANCE OSCILLATION IS OBSERVED TO OCCUR IN THE INNER DECK OF THE SINGLE-DECK TYPE ROOF. 4) IN ORDER TO PREVENT THE DAMAGES OF THE FLOATING ROOF AS EXPERIENCED DURING THE 2003 TOKACHIOKI EARTHQUAKE, IT IS RECOMMENDED TO REPRACE THE SINGLE-DECK TYPE ROOF BY THE DOBLE-DECK TYPE ROOF OR THE RIB-STIFFENED ROOF. Less