Non-linear analysis on steel transmission tower using beam-column method

For reflecting the actual working of the tower transmission, requirements about analysis model and review during processes used in the design must be determined and clearly assessed.The non-elastic analysis will directly overcome the disadvantages of methods that were based on linear elastic analysis above-mentioned. Main advantage of this method which based on direct analysis of nonlinear geometric effects and nonlinear materials is: (i) without using coefficientof computed length because nonlinear geometric effects are integrated directly; (ii) the interaction due to plastic flow and gradual instability as per increasing load is taken into account; (iii) to provide results of internal forces of the entire structure with consideration over the internal force redistribution as true status of the system; (iv) to predict the stiffness of the structures transmission tower with a more accuracy; (v) to figure out the nonlinear behavior of the system, order and modes of failure of structures and structural systems, as well as ultimate bearing capacity of the system; (vi)to apply suitably and reasonably all kind of frame structures including unbracing frame, bracing frame and mixed frames.In this paper, following problems have been solved: Beam-column method using stability function with plastic hinged in both ends in order to describe the nonlinear behavior of structural steel transmission tower, then a nonlinear algorithm for analyzing the system subjected to static load was created. A practicable Fortran program for analyzing nonlinear system rigid frame, bracing frames, steel frames and power supply towers was established. After then, the reliability of the developed program has been evaluated and compared to that ofSAP2000 results. Finally, developed programs was used to design electricity transmission towers

Nonlinear geometric analysis of steel frames by beam-column method.

Nonlineargeometricismentionof geometric errorof structureatthe pointincreasing forceandthe nonlinearmaterialismentionof a change material. Nonlineargeometricanalysis byusingbeam-column method andnonlinearmaterialsthat includingplastichinge oftheendingelementsfor simulationtheworkingoftheelementsas wellastheentirethe trusses systemunderthe effect ofexternal forces. Beam-column includingthe effects ofcompressionandbendingthat describesthecombininganalysis of thedeviationof the beamgeometryandstability issuesoftheload-bearingcolumn. The articleusesadvanced analyticalmethods to analyzethe relationship betweenforceanddisplacementofthe trusses systemthroughquadratic curvewhich includingthecombination of effects, Analysisthe relationship between theforce-displacement ateachincreasingforcepoint andthe point reaching structure’slimit. Using thestabilityof beam-column methodenablesto reduce the declarationofelement,reduceanalysis timeand reduce the problem of computer memorycach

Effects of Titanium Powder Concentrations on Material Removal Rate and Surface Roughness of H13 Steel in Electrical Discharge Machining with Graphite Electrode

Electrical discharge machining (EDM) has been widely used in both tool and mould industries. Enhancing productivity and workpiece surface roughness is the concern of many researchers. In this research, the effects of titanium powder concentrations on surface roughness (Ra) and material removal rate (MRR) in a machining operation on Powder Mixed EDM (PMEDM) is investigated. Two types of material : H13 hot work steel and the graphite Gr) electrode tool which have found widespread applications in EDM are under investigation. With the method of experimental evaluation with fixed processing parameters and variable concentrations of titanium powder, the results showed that concentrations of powder have great influence on the surface roughness and material removal rate in PMEDM

Nguồn lực và động lực phát triển trong nền kinh tế thị trường định hướng Xã hội Chủ nghĩa ở Việt Nam

291 tr. ; 21 c