scholarly journals PROBABILITY‐BASED DESIGN OF SPUN CONCRETE BEAM‐COLUMNS

2010 ◽  
Vol 16 (4) ◽  
pp. 451-461 ◽  
Author(s):  
Antanas Kudzys ◽  
Romualdas Kliukas

The attention of engineers is turned to the application of precast spun concrete columns reinforced by high‐strength steel bars for office and administrative buildings. The paper discusses a possibility of using the reliability index approach to designing beam‐columns of building frames and analyses resistance criteria for beam‐columns of annular cross sections as compression members with bending moments and bending members with compressive forces. First and second order effects of beam‐columns are considered. The article also presents time‐dependent resistance safety margin and its stationary equivalent and investigates the unsophisticated applied models for probability‐based design of frame beam‐columns. The design of a beam‐column of the braced frames is illustrated providing a numerical example. Santrauka Atkreiptas inžinieriu demesys i didžiastiprio plieno strypais armuotu sijiniu kolonu iš centrifuguotojo betono naudojima istaigu ir administraciniuose pastatuose. Aptarta galimybe projektuojant pastato remo sijines kolonas taikyti patikimumo indekso būda. Analizuojamas sijiniu kolonu kaip lenkiamai gniuždomu ir gniuždomai lenkiamu žiedinio skerspjūvio ele‐mentu atspario kriterijus. Nagrinejamos sijiniu kolonu pirmosios ir antrosios eiles iražos. Pateiktas laike kintantis ribines saugos atsparis ir jo stacionarusis ekvivalentas. Tyrinejamas nesudetingas taikomasis modelis remo sijiniu kolonu ti‐kimybiniam projektavimui. Skaitiniu pavyzdžiu iliustruojamas stabilizuojamu remu sijines kolonos projektavimas.

2010 ◽  
Vol 16 (2) ◽  
pp. 189-196 ◽  
Author(s):  
Romualdas Kliukas ◽  
Antanas Kudzys ◽  
Romualdas Vadlūga

The expediency of reinforcing precast spun concrete members of annular cross sections reinforced by high‐strength steel bars is discussed. Test materials, mechanical properties, production and testing procedures of plain and rein‐forced spun concrete specimens are presented. The quasi‐ductile strength and strain features of concentrically and eccentrically loaded specimens are considered. The modelling of a bearing capacity of beam‐columns of annular cross sections is based on the concepts of bending with a concentrical force and compression with a bending moment. The comparison of modelling and test data of spun concrete beam‐columns is analysed. Santrauka Aptariamas didžiastipriais plieniniais strypais armuotu gamykliniu žiedinio skerspjūvio elementu iš centrifuguotojo betono tinkamumas. Pateiktos grynojo ir armuotojo centrifuguotojo betono bandiniu medžiagos, mechanines savybes, gamybos ir bandymo tvarka. Nagrinejamos centriškai ir ekscentriškai apkrautu bandiniu tartum stamantraus stiprumo ir deformaciju ypatybes. Žiedinio skerspjūvio sijiniu kolonu laikomajai galiai modeliuoti taikomos gniuždomojo lenkimo ir lenkiamojo gniuždymo sampratos. Analizuojami sijiniu kolonu iš centrifuguotojo betono modeliavimo ir bandymo duomenys.


2018 ◽  
Vol 33 (3-4) ◽  
pp. 138-149 ◽  
Author(s):  
Marco Bonopera ◽  
Kuo-Chun Chang ◽  
Chun-Chung Chen ◽  
Tzu-Kang Lin ◽  
Nerio Tullini

This article compares two nondestructive static methods used for the axial load assessment in prismatic beam-columns of space trusses. Examples include the struts and ties or the tension chords and diagonal braces of steel pipe racks or roof trusses. The first method requires knowledge of the beam-column’s flexural rigidity under investigation, whereas the second requires knowledge of the corresponding Euler buckling load. In both procedures, short-term flexural displacements must be measured at the given cross sections along the beam-column under examination and subjected to an additional transverse load. The proposed methods were verified by numerical and laboratory tests on beams of a small-scale space truss prototype made from aluminum alloy and rigid connections. In general, if the higher second-order effects are induced during testing and the corresponding total displacements are accurately measured, it would be easy to obtain tensile and compressive force estimations.


2009 ◽  
Vol 15 (3) ◽  
pp. 289-297 ◽  
Author(s):  
Antanas Kudzys ◽  
Romualdas Kliukas

The expediency of using precast spun concrete columns of annular cross‐sections reinforced by high‐strength steel bars is discussed. Test material properties, efficiency factors and resisting compressive stresses of plain and reinforced spun concretes are presented. Modelling a bearing capacity of eccentrically loaded members of annular cross‐sections is based on the concepts of compression with a bending moment and bending with a concentrical force. The comparison of test and modelling data of concentrically and eccentrically loaded members is analysed. The expediency to use in design practice the approaches of current methods of partial safety factors design (PSFD) legitimated in Europe and load and resistance factors design (LRFD) suggested in the USA and other countries is considered and illustrated by a numerical example. Santrauka Aptariamas didžiastiprio plieno strypais armuotų žiedinio skerspjūvio centrifuguotojo betono kolonų naudotinumas. Pateiktos armuotojo ir nearmuotojo centrifuguotojo betono medžiagų savybės, efektyvumo veiksniai ir laikomieji gniuždymo įtempiai. Ekscentriškai gniuždomų žiedinio skerspjūvio elementų laikomajai galiai modeliuoti taikomos lenkiamojo gniuždymo ir gniuždomojo lenkimo sampratos. Analizuojamas centriškai ir ekscentriškai apkrautų elementų eksperimentinių ir modeliavimo duomenų sugretinimas, nagrinėjamas Europos, JAV ir kitų šalių projektavimo praktikoje įteisintų ir paplitusių dalinių veiksnių ir apkrovų bei atsparių veiksnių metodų taikymo tikslingumas, kurį rodo skaitmeninis pavyzdys.


2022 ◽  
pp. 136943322110651
Author(s):  
Mizan Ahmed ◽  
Qing Quan Liang ◽  
Ahmed Hamoda

Circular concrete-filled double-skin steel tubular (CFDST) columns with external stainless-steel are high-performance composite columns that have potential applications in civil construction including the construction of offshore structures, bridge piers, and transmission towers. Reflecting the limited research performed on investigating their mechanical performance, this study develops a computationally efficient fiber model to simulate the responses of short and slender beam-columns accounting for the influences of material and geometric nonlinearities. Accurate material laws of stainless steel, carbon steel, and confined concrete are implemented in the mathematical modeling scheme developed. A new solution algorithm based on the Regula-Falsi method is developed to maintain the equilibrium condition. The independent test results of short and slender CFDST beam-column are utilized to validate the accuracy of the theoretical solutions. The influences of various column parameters are studied on the load-axial strain [Formula: see text] curves, load-lateral deflection [Formula: see text] curves, column strength curves, and interaction curves of CFDST columns. Design formulas are suggested for designing short and beam-columns and validated against the numerical results. The computational model is found to be capable of simulating the responses of CFDST short and slender columns reasonably well. Parametric studies show that the consideration of the concrete confinement is important for the accuracy of the prediction of their mechanical responses. Furthermore, high-strength concrete can be utilized to enhance their load-carrying capacity particularly for short and intermediate slender beam-columns. The strengths of CFDST columns computed by the suggested design model are in good agreement with the test and numerical results.


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