Finite Element Analysis of Von-Mises Stress Distribution in a Spherical Shell of Liquified Natural Gas (Lng) Pressure Vessels
This research work investigated the modeling of Von Mises stress in LNG Spherical Carbon Steel Storage tank using assumed displacement Finite Element analysis based on shallow shell triangular elements. Using equations of elasticity, constant thickness carbon steel spherical storage tanks were subjected to different loading conditions. This paper stresses the need for proper definition of shallow element using sector angles to obtain the shallowness. The shallow spherical triangular element has five degrees of freedom at each of its corner node, which are the essential external degrees of freedom. The assumed displacement fields of these shallow triangular elements satisfied the exact requirement of rigid body modes of motion. The FORTRAN 90 programming language was used for the programme coding to solve finite element equations resulting from the model while Von Mises stresses distribution within the spherical storage tank shell subjected to different internal pressures were determined. The results showed that the use of non-shallow elements due to improper sector angles resulted in unreliable results while real shallow elements produced results that tallied with ASME Section VIII Div 1, Part UG values.
DEVELOPMENT OF THE WORLD'S LARGEST ABOVE-GROUND FULL CONTAINMENT LNG STORAGE TANK
Korea Gas Corporation (KOGAS) has developed the world’s largest above-ground full containment LNG storage tank with a gross capacity of 200,000m. The main objective of the development of the large capacity LNG storage tank is to reduce the construction cost and the boil-off gas and use the tank building site more effectively. The large tank was designed for the KOGAS’ Tongyoung and Pyeongtaek LNG Receiving Terminals. The design work was done through numerous structural, thermal and seismic analyses. The tank consists of 9% nickel steel inner tank, pre-stressed concrete outer tank, suspended ceiling deck, secondary bottom and corner protection system, and bottom heating system. The design boil-off rate (BOR) used in the design is 0.05% in volume per day. The inner tank has a diameter of 84m and the thickness of shell insulation is 1200mm. The 9% nickel steel plates with a thickness of 32.9mm were used for the first course of inner shell. The design was used for the construction of new tanks in the Tongyoung and Pyeongtaek LNG Receiving Terminals. This paper introduces the basic design concept and features of the large capacity 9% nickel full containment LNG storage tank developed by KOGAS.
RIP - General Purpose Interactive Display at HHIRF
RIP is a general purpose interactive code for display and analysis of data acquired with the Holifield Heavy Ion Research Facility (HHIRF) accelerators at Oak Ridge National Laboratory. The HHIRF data acquisition system includes a version of RIP for on-line display of one-and two-dimensional histograms on color graphic terminals and hard copy on color printer/plotters. General features of the program and interactive techniques will be described.