Offshore wind-turbine support structures are largely made of steel since monopiles have accounted for the majority installations in last decade. As turbines become bigger, led to an exponential increase material and installation costs. From this point view, use concrete future has been initiated. In study, concrete–steel composite piles investigated. A pre-tensioned high strength pile was place...

The large amplitude steady state forced motion of a simply supported beam with ends restrained to remain a fixed distance apart is represented by a series of linear normal modes. The validity of the assumption of single mode response is examined by investigating the stability of the unforced modes when a single mode is forced. The equations include the effects of an initial axial load and numer...

retrofitting structures is an important issue. structural weakness may be due to changes in design codes or defects in implementation. adding structural floors to the existing structures may also lead to the need for strengthening and retrofitting. retrofitting is possible before the earthquake or may take place as rehabilitation of damaged members after earthquake. elements such as columns in ...

In this paper the effect of random geometric imperfections on the critical load of isotropic, thin-walled, cylindrical shells under axial compression with rectangular cutouts is presented. Second moment characteristics of geometric imperfections are estimated by data of available measurements, a simulation procedure based on the Karhunen-Loéve expansion is applied for generating realizations of...

The interaction between Euler buckling and Brazier instability in an orthotropic cylindrical tube was investigated. A simple closed-form interaction curve was obtained by using the principle of minimum potential energy including the 3D extended Brazier’s 2D type cross-section ovalization and the potential energy of axial compression. The interaction curve consists of an Euler buckling load and ...

Though asymmetric loading between the medial and lateral compartments of total knee replacements may contribute to implant loosening and failure, the in vivo contact force distribution during dynamic daily activities remains unknown. This study reports in vivo medial and lateral contact forces experienced by a well-aligned knee implant for a variety of activities. In vivo implant motion and tot...

Torsional dynamic analysis of carbon nanotubes under the effect of longitudinal magnetic field is carried out in the present study. Torque effect of an axial magnetic field on a carbon nanotube has been defined using Maxwell’s relation. Nonlocal governing equation and boundary conditions for carbon nanotubes are obtained by using Hamilton’s minimum energy principle. Eringen’s nonlocal stress gr...

The main objective of the paper is to demonstrate the computer simulation and energy absorption of tapered tubes under impact load. The study of the impact load includes axial compression, bending and torsion. In general, one could rely on the use of finite element analysis to determine the energy absorption capacity of the energy absorbers. This tool is helpful and accuracy. The parametric var...