LNG ship structure assembly dislocation detection method

The invention discloses an LNG ship structure assembly dislocation detection method. An adopted specially-made dislocation detection tool comprises an overlapping panel, a clamping groove is formed onthe overlapping panel, and a front overlapping plate and a back overlapping plate are formed at the two sides of the clamping groove respectively. The dislocation detection method comprises the following steps of 1, making a back structure inspection line on the lower surface of an inner bottom plate, wherein the back structure inspection line is parallel to a lower rib plate installation reference line; 2, clamping the clamping groove from the end of the inner bottom plate along the inner bottom plate, and overlapping one side of the back overlapping plate with the back structure inspectionline; 3, making a front structure inspection line on the upper surface of the inner bottom plate along one side of the front overlapping plate; and 4, measuring the distance between the front structure inspection line and an upper rib plate installation reference line, and calculating an assembly dislocation value of an upper rib plate and a lower rib plate. The dislocation detection method is simple and easy to understand, and can quickly and accurately judge whether the installation reference lines of the upper rib plate and the lower rib plate of the double-layer bottoms are dislocated or not.