in this study, a new method for joining aluminum tubes in subsurface structures using steel converting and aluminum welding are presented and reviewed. but near the weld area is under high thermal cycle and will cause residual stresses in heat affected zone. therefore for assessment of proposed connection from the perspective of residual stress by using the finite element method welding of tube...

the complete 3d nonlinear dynamic problem of extensible, flexible risers conveying fluid is considered. for describing the dynamics of the system, the newtonian derivation procedure is followed. the velocity field inside the pipe formulated using hydrostatic and bernoulli equations. the hydrodynamic effects of external fluids are taken into consideration through the nonlinear drag forces in var...

in saturated soils, heating induces thermal expansion of both grains and the pore fluid. lower thermal expansion coefficient of aggregates results in the increase of pore pressure and reduction of the effective stress besides subsequent volume changes due to the dissipation of pore pressure and heat transfer. dissipation of thermally induced pore pressure with time is a coupled thermo-hydro-mec...

sandwich sheet rolling process is investigated using an analytical method (slab method) and a numerical method (finite element method). the horizontal stress distribution in the layers, the rolling pressure along the contact interface and the neutral point between the roll and the sheet are investigated. then the affects of the parameters such as the friction between the sheet and the roll, she...

shape error due to elastic recovery of formed part in unloading known as springback, is one of the most important problems of tool design in sheet metal forming processes. many researches have been performed for proposing an efficient method to decrease or compensate springback error in sheet forming processes. these methods are usually based on iterative finite element algorithms. in this pape...

in recent years, the application of composite materials in aircraft and space vehicle structural components has become increasingly popular. preventing failure of composite structural systems has been an important issue in engineering design. due to the lack of through-the-thickness reinforcement, structures made from laminated composite materials and adhesively bonded joints are highly suscept...

many procedures suggest for reduction of responses of riser to vortex induced vibrations (viv). natural frequencies of marine risers is an important parameter that can affect the responses of riser to viv. change of riser properties such as top tension and bending stiffness can alter natural frequencies. in this study effects of riser specifications on the responses and fatigue damage of marine...

rectangular waveguide (wr) is one of the earliest types of transmission lines. rectangular waveguide can be produced by hot extrusion process. in this paper, the hot extrusion process of cuzn5 rectangular waveguide was investigated by finite element method (fem). in addition, genetic algorithm method (ga) was used to optimize the die geometry and process conditions to achieve the lowest magnitu...

drying is an important operational step in pistachio processing. there is a decrease in moisture content of pistachio nuts from 56-57% (d.b.) to 5-6% during the drying process. drying conditions affect the quality of dried pistachio nuts, therefore, this calls for an accurate description of the drying trend in the process. in this study finite element formulation and solution of diffusive moist...