The objective of this research is to evaluate crack growth behavior from a surface crack to a through crack in a liquefied natural gas (LNG) tank . Crack growth behavior is analyzed by superposition version FEM (S-FEM). As a crack grows, part of the local mesh crosses over the global mesh. In S-FEM, the local mesh is defined as existing in the global mesh. When a part of the local mesh crosses over the global mesh, the Young’s modulus of the part is made small to ignore the influence of the part. In this way, the stress distribution of the local mesh is improved. In this study, crack growth behavior under a tensile cyclic load is analyzed. After crack penetration, the crack shape becomes rectangular. Crack growth behavior under tensile bending loading is also analyzed by simulating the four-point bending test. In this simulation, the crack shape becomes trapezoidal after penetration.
Mechanical Engineering, Tokyo University of Science,Suwa, Japan
Mechanical Engineering, Faculty of Science and Technology, Graduate School of Tokyo University of Science, Japan
Mechanical Engineering, Faculty of Science and Technology, Tokyo University of Science, Japan
A study of the effect of the well-known aerodynamic device low profile vortex generators (VGs) on the viscous resistance of the DTMB 5415 ship hull form through the control of the ship boundary layer separation is performed using the finite volume code Ansys CFX. The tetrahedral unstructural grids have been used for meshing the different cases. Different types of VGs have been tested, but the study has forced on two main types of VGs. The effects of VGs on the ship viscous resistance and its components have been investigated for the different cases in this study, and comparisons between the various results have been made.
Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310, UTM , Skudai, Johor, Malaysia
Faculty of Engineering, Alexandria University, Egypt
The underwater glider is used for deep water to observe large areas with minimal use of energy and move through the water by changing the body weight. The glider contained a cylindrical body attached with two wings and a fix tail. The controller has been designed to use a comparator circuit integrate with a pressure sensor to control the depth level. The pressure sensor mounted on the glider used to sense the underwater pressure. For the beginning, this underwater glider is limited to a depth of 0-10 meters.
Universiti Kuala Lumpur, Malaysian Institute of Marine Engineering Technology, Lumut, Perak, Malaysia
UniversitiTeknologi Malaysia, Faculty of Electrical Engineering, Skudai, Johor, Malaysia
Podded propulsion system becomes common installed in ships due to high maneuvering. The purpose of this paper is to discuss performance of both VLCC ships with podded propulsion and rudder. As initial offset data, published ship (SR221A) was used for generating hull form of a podded propulsion ship using Maxsurf software by maintaining the principal dimension: length, breadth, and draft. In order to suit installation of podded house, the stern part was modified. The hydrostatic data of both ships with podded propulsion and rudder are transferred to Ship Resistance and Propulsion Simulation software to determine the running speed by given same power. It was found that running speed produced by a ship using pod propulsion system lower than the speed produced by a ship using rudder.
Department of Aeronautics, Automotive and Ocean Engineering, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, Malaysia
Ocean and Aerospace Engineering Research Institute, Indonesia