Moment-resisting frames have extensive usage in earthquake-prone areas and high ability in energy dissipation.After the earthquake in Northridge 1994,Kobe 1995 fixed connections of steel structures have shown poor performance and generally they were caught brittle fracture of beam flange weld to the column.In order to remedy to avoid similar situations in future earthquakes,researchers introduc...

crack identification is a very important issue in mechanical systems, because it is a damage that if develops may cause catastrophic failure. in the first part of this research, modal analysis of a multi-cracked variable cross-section beam is done using finite element method. then, the obtained results are validated usingthe results of experimental modal analysis tests. in the next part, a nove...

Crack identification is a very important issue in mechanical systems, because it is a damage that if develops may cause catastrophic failure. In the first part of this research, modal analysis of a multi-cracked variable cross-section beam is done using finite element method. Then, the obtained results are validated usingthe results of experimental modal analysis tests. In the next part, a nove...

The scattering characteristic of paraxial gaussian beam from two dimensional dielectric rough surfaces is studied in this paper. The modification of the Kirchhoff approximation theory for rough surface scattering by an incident gaussian beam instead of a plane wave are developed based on conventional Kirchhoff scattering theory and plane wave spectrum expansion method. The coherent and incohere...

By using the OTR angular distribution property [1], it is possible to extract the energy and the angular dispersion of several kinds of beam [2]. Recently, Le Sage et al. [3] succeeded in producing a transverse phase-space mapping of a 100 MeV electron beam by coupling an interferometric measurement and a ’’mask’’ technique. We present the first OTR time resolved angular distribution measuremen...

The system is intended to determine the beam profile at the DESY-FLASH undulator section as well as measuring beam losses with high spatial resolution. The measurement setup is based on wire scanners, optical fibers which are symmetrically mounted around the beam line over the full length (30 m) of the undulator section, a signal conditioning unit and a data acquisition system. The optical fibe...

Abstract: An elastic stiffness matrix was derived in the case of distortion of a restrained thinwalled I-section beam using the minimum total stationary elastic energy condition (Przemieniecki J S 1968 Theory of Matrix Structural Analysis, McGraw-Hill, NY). The function describing the angle of distortion was adopted form the solution of differential equation in the case of restrained distortion...