in the current engineering practices, buildings are commonly designed for an effective lifetime of 50 years. this lifetime can increase the cost of buildings with short lifetimes and can reduce the safety level of buildings with large lifetimes. in this paper, a “service-life factor” has been defined. applying this factor into the nominal values of live, earthquake, wind, and snow loads, the ef...

in this research, the calculation method of aerodynamic loads on an airplane in all flight situations is presented. in order to find an calculation equation for aerodynamic loads on an airplane in all flight conditions, the f-5 aircraft is selected as a prototype is divided into one hundred small parts longitudinally. therefore, the numerical solutions are taken place in different conditions of...

the plate girders are used in important structural systems. the earlier design of plate girders was restricted to their critical bukling capacity. experimental and theoretical studies show the plate girders with vertical stiffners can carry load over than their critical buckling loads and then in modern design codes is permitted to use post- buckling capacity of them. in this case the out- of- ...

High levels of strength- and stiffness-to-mass ratio can be achieved in slender structures by lengthwise tailoring their cross-sectional areas. During use, a non-prismatic beam element subject to surface forces or loads acting on only part cross-section. Practical examples involve tapered aircraft wings, wind turbine helicopter rotor blades under fluid pressure shear forces; arched beams bridge...

Piezoelectric material has been emerging as a popular building block in MEMS devices owing to its unique mechanical and electrical material properties. However, the reliability of MEMS devices under buckling deformation environments remains elusive and needs to be further explored. Based on the Talreja's tensor valued internal state damage variables as well as the Helmhotlz free energy of piezo...

A semi-analytical approach to the elastic nonlinear stability analysis of rectangular plates is developed. Arbitrary boundary conditions and general out-of-plane and in-plane loads are considered. The geometrically nonlinear formulation for the elastic rectangular plate is derived using the thin plate theory with the nonlinear von Kármán strains and the variational multi-term extended Kantorovi...

it is proposed to use a single base platform in the persian gulf considering its low depth and more appropriate environmental conditions in comparison to north sea and mexico gulf where this kind of platform is very popular. the pile of platform is responsible for transmission of environmental loads resulted from waves, currents, wind and dead loads to foundation of platform. using sacs 5.3 sof...

The finite element method (FEM) can be applied to practically analyze the tall buildings in which the shear walls are used to resist the lateral loads. Accordingly, a variety of displacement and strain-based as well as frame macro elements have been proposed for analysis of the tall buildings. With respect to application of the lower order plane stress elements, analytical problems may arise wi...