Experimental research on load of transversal roof bracing due to geometrical imperfections of truss

The presented paper deals with the stochastic analysis of the ultimate limit states of steel‐concrete building members. The load carrying capacity of steel‐concrete columns, comprising of steel profiles encased in high strength concrete, in compression is analyzed. The first part of the paper lists assumptions for the determination of the theoretical load carrying capacity of the column. Principles of elasticity and plasticity are used to determine stresses in the concrete and steel sections. Statistical characteristics of input material and geometrical imperfections are listed. Results of the theoretical analysis are then compared with results of experimental research. Statistical characteristics of obtained results of the theoretical analysis were verified using statistical characteristics obtained from experimental research. Numerical simulation LHS and Monte Carlo methods, which take into account the influences of variability of input imperfections, were employed. The influence of the utilization of the plastic reserve in the determination of the load carrying capacity of the analysed strut is shown. The influence of the initial geometric imperfections of initial strut curvature on the load carrying capacity is also presented. Santrauka Straipsnyje pateikta plienbetonio pastatu elementu didžiausiu ribiniu būkliu stochastine analize, analizuojama plienbetonio kolonu, sudarytu iš plieniniu profiliuočiu, padengtu didelio stiprio betonu, laikomoji galia gniuždant. Pirmoje straipsnio dalyje išvardytos kolonos teorines laikomosios galios nustatymo prielaidos. Tamprumo ir plastiškumo principai taikyti itempiams betono ir plieno skerspjūviuose nustatyti. Nustatytos medžiagu ir geometriniu defektu statistines charakteristikos, teorines analizes rezultatai palyginti su eksperimentiniu tyrimu rezultatais. Teorines analizes metu gautu rezultatu statistines charakteristikos patikrintos taikant iš eksperimentiniu tyrimu gautus statistinius rodiklius. Pritaikytas skaitinis modeliavimas LHS ir Monte Karlo metodais, kurie ivertina pradiniu defektu kintamumo itaka. Parodyta plastiškumo atsargos naudojimo itaka, nustatant analizuojamojo statramsčio laikomaja galia, pateikta pradinio statramsčio išlinkio pirminiu geometriniu defektu itaka laikomajai galiai.

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Impact of truss girder geometrical imperfections on roof bracing load

MATEC Web of Conferences ◽

10.1051/matecconf/201926209008 ◽

2019 ◽

Vol 262 ◽

pp. 09008

Author(s):

Piątkowski Michał

Keyword(s):

Numerical Analysis ◽

Experimental Research ◽

Test Results ◽

Research Results ◽

Maximum Value ◽

Test Models ◽

Steel Truss ◽

Geometrical Imperfections

The author has presented in this paper his own experimental research on the maximum value and distribution of load in transverse roof bracing caused by a planar truss girder with geometrical imperfections. The tests were performed on 7.0 m long test models of steel truss made of square hollow sections. The tests performed verify standard recommendations concerning adoption of uniformly distributed notional load of transverse roof bracing and confirm the relations indicated in the discussed literature. The experimental research results were cross-checked by relevant numerical analysis. A comparison of notional loads recommended by the standard and literature with test results was performed and conclusions were formulated.

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Secondary Transfer Effect of Contact

Social Psychology ◽

10.1027/1864-9335.40.2.55 ◽

2009 ◽

Vol 40 (2) ◽

pp. 55-65 ◽

Cited By ~ 146

Author(s):

Thomas F. Pettigrew

Keyword(s):

Cognitive Dissonance ◽

Experimental Research ◽

Intergroup Contact ◽

Transfer Effect ◽

Evaluative Conditioning ◽

Transfer Effects ◽

Secondary Transfer ◽

Primary Reduction

This paper reviews the evidence for a secondary transfer effect of intergroup contact. Following a contact’s typical primary reduction in prejudice toward the outgroup involved in the contact, this effect involves a further, secondary reduction in prejudice toward noninvolved outgroups. Employing longitudinal German probability samples, we found that significant secondary transfer effects of intergroup contact exist, but they were limited to specific outgroups that are similar to the contacted outgroup in perceived stereotypes, status or stigma. Since the contact-prejudice link is bidirectional, the effect is inflated when prior prejudice reducing contact is not controlled. The strongest evidence derives from experimental research. Both cognitive (dissonance) and affective (evaluative conditioning) explanations for the effect are offered.

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