LNG储罐预应力混凝土外罐应力分布与裂缝形态

Stress distribution and crack form of the prestressed concrete outer tank of LNG tank

LNG储罐的外罐主要是由预应力混凝土建造而成,混凝土作为一种复杂的非线性材料,其受力特点为抗压不抗拉。应用ADINA有限元软件,建立钢筋混凝土分离式模型,通过应力云图及裂缝开展图,研究LNG储罐在正常使用状态及内罐完全泄漏状态下预应力混凝土的应力分布、裂缝开展情况及破坏形态。结果表明:在正常使用状态下,外罐上下两固定端第一主应力最大;在内罐泄漏状态下,底部约1/4高度第一主应力最大,此三处为外罐最易产生裂缝的部位,破坏形态均为混凝土受拉破坏。研究结果为国内LNG储罐的自主设计与建造提供了理论依据。

The outer tank of LNG storage tank is mainly composed of the prestressed concrete,and as a kind of complex nonlinear material,the concrete's load feature is compressive and no-tensile.LNG tanks is a typical kind of pressure vessel,especially thelarge-scale LNG tanks.The research on stress distribution and crack development of concrete outer tank is of significance.With the f inite element software ADINA,the separated model of reinforced concrete is established.With the stress cloud picture and crack development f igure,under the conditions of LNG storage tank in the normal running and total leakage state,the research on the stress distribution of the prestressed concrete,crack development situation and its failure pattern is carried out.The result shows that the first principal stress at the two fixed ends is the largest in normal running condition,the f irst principal stress at a quarter height distance from the bottom is the largest in total leakage state of inner tank,and the three locations are the most vulnerable to crack,and their failure pattern is concrete tensile failure.The result provides a theoretical basis for independent design and construction of domestic LNG tank.