Theory and design of optimum FIR compaction filters

The problem of optimum FIR energy compaction filter design for a given number of channels M and a filter order N is considered. The special cases where N相似文献   

Experimental and code based study of beam-column behaviour of equal leg single-angles

This study intends to establish the behaviour of equal leg single-angles under bi-axial bending and compression experimentally and analytically using nonlinear finite element analysis techniques. In the experimental system, 100×100×10 nominally sized equal leg single-angles were tested. The legs of angles were placed in a flange-down position, and their axes were restrained laterally as a simply supported beam. These simply supported beams were loaded with a concentrated vertical load applied at the middle of the length and an axial load parallel to the beam axis until failure was reached. The FEM model of the experimental system was generated with ABAQUS software. Suitable finite element mesh configurations, boundary conditions and nonlinear analysis solution techniques were determined to identify the system behaviour. The test and ABAQUS software results were interpreted using some code specifications and one design procedure.     

Analytical and parametric investigations on lateral torsional buckling of European IPE and IPN beams

Lateral torsional buckling is one of the main failure modes controlling the strength of the slender thin-walled members. A transversely or transversely and axially combined loaded member that is bent with respect to its axis of greatest flexural rigidity may buckle laterally and twist as applied load reaches its critical value unless the beam is provided with a sufficient lateral support. This study intends to present a unique convenient equation that it can be used for calculating critical lateral-torsional buckling load of simply supported European IPE and IPN beams. First, an analytical model is introduced to describe lateraltorsional buckling behavior of beams with monosymmetric cross-section. The analytical model includes first order bending distribution, load height level and monosymmetry property of the section. Then, parametric study is carried out using the analytical solutions in order to establish a simplified equation with dimensionless coefficients. The effect of slenderness and loading positions on lateral-torsional buckling behavior of IPE and IPN beams are studied. The proposed solutions are compared to finite element simulations where thin-walled shell elements and beam elements including warping are used. Good agreement between the analytical, parametric and numerical solutions is demonstrated. It is found out that the lateral-torsional buckling load of European IPE and IPE beams can be determined by presented equation and can be safely used in design procedures.