Wyniki wyszukiwania - BazTech

1

Experimental study on the cyclic behavior of perforated CFRP strengthened steel shear walls

Sahebjam A., Showkati H.

Archives of Civil and Mechanical Engineering

|

2016

|

Vol. 16, no. 3

365--379

EN

In this study, the behavior of perforated carbon fiber reinforced polymer–steel composite shear walls under a quasi-static cyclic loading was investigated. Four single-story and single-bay specimens were manufactured with an aspect ratio of 1.33: a simple perforated steel shear wall as a reference model and three perforated composite shear walls. The composite specimens differed in their fiber directions. All specimens had a regular staggered pattern of circular openings. Parametric studies on the stiffness, load-carrying capacity, and ductility were carried out using hysteresis curves. As a detailed new study the strain on the infill panel and buckling waves were also monitored. All the fiber directions were found to considerably affect the stress distribution and tension field direction. While, hysteresis curves indicated that orienting the fibers along the tension field considerably affected the curves and the above parameters, but the effect of fiber orientations in the horizontal and vertical was negligible.

2

Elastic stiffness of reverse channel joint web components under bolt tension

Jafarian M., Wang Y. C.

Archives of Civil and Mechanical Engineering

|

2016

|

Vol. 16, no. 4

961--981

EN

Reverse channel joint is a convenient method to make connection between steel beam and steel tubular column (with or without concrete infill). This paper presents analytical solutions for evaluating the elastic stiffness of reverse channel joint web component under bolt tension. The design parameters that affect the reverse channel web elastic stiffness include bolt position, edge distance, number of bolt rows, pitch between the bolts, depth of the reverse channel's flange, and type of the reverse channel. Starting from the load-deflection solution of an infinitely long plate with simply supported edges under lateral point load, this paper makes a number of simplifying assumptions to deal with the various issues of using practical reverse channel webs. These issues include finite length of reverse channel, rotational restraint from the reverse channel flanges, realistic reverse channel profile and more than one row of bolts. This paper presents validation for each simplification by comparing the analytical solutions with numerical simulation results using the general finite element software ABAQUS. Accuracy of the final formulations was checked against available experimental results, some of which were carried out by the authors. For comparison, extensive numerical simulations were carried out to cover all possible ranges of practical design parameters, which included number of bolt rows, bolt positions (pitch, gauge, end/edge distances), reverse channel type (cut from square tube with equal flange/web thickness, cut from rolled channels with thicker flange/thinner web) and reverse channel dimensions (length, web width, flange width, thickness). In all cases, the proposed analytical solution was shown to give sufficiently accurate results.

3

Structural and mechanical properties of ZnTe in the zincblende phase

Soykan C., Ozdemir Kart S., Cagin T.

Archives of Materials Science and Engineering

|

2010

|

Vol. 46, nr 2

115-119

EN

Purpose: The aim of this work investigate to the structural and mechanical properties of ZnTe in the B3 structure, using the ab initio method based on Density Functional Theory (DFT). Design/methodology/approach: The Vienna ab initio Simulation Package (VASP) has been used to perform the electronic structure calculations. The projector-augmented wave formalism (PAW) implemented in this package leads to very accurate result comparable to other all-electron methods. The electronic exchange and correlation functions are treated within DFT by using generalized gradient approximation. Findings: The lattice parameter, bulk modulus, it's pressure derivative and the elastic stiffness coefficients are calculated. Our results for the structural parameters and the elastic constants at the equilibrium phase are in good agreement with the available experimental and other theoretical studies. We have also investigated the pressure dependence of mechanical properties for ZnTe in the structure of B3 to see this effect. Research limitations/implications: These compounds are convenient for many technological applications because of they have direct energy band gaps and property of light emitters at room temperature. Practical implications: These compounds used to many technological applications, such as solid state laser devices, photovoltaic devices, solar cells, remote control systems, thin films, transistors, THz emitter, detector and imaging systems etc. Originality/value: In this work, determination of structural and mechanical properties of ZnTe in the B3 structure at high pressures will lead to new technological applications of these materials.