土木工程畢業(yè)設(shè)計(jì)外文翻譯-建筑結(jié)構(gòu)-全文預(yù)覽
【正文】 escending portion (seefig. 2). The portion beyond ultimate defines the postultimate stress capacity of 寧波工程學(xué)院畢業(yè)設(shè)計(jì)（論文） 1 the material which, Typical stressstrain relationship for concrete in pression. as indicated in figure 1, is generally considered to make a major contribution to the maximum loadcarrying capacity of the beam. However, a recent analytical investigation of the behaviour of concrete under concentrations of load has indicated that the postultimate strength deformational response of concrete under pressive states of stress has no apparent effect on the overall behaviour of the structural forms investigated ( [2], [3]). If such behaviour is typical for any structure, then the large pressive strains (in excess of ) measured on the top surface of a reinforced concrete beam at its ultimate limit state (see fig. 1), cannot be attributed to postultimate uniaxial stressstrain characteristics. Furthermore, since the pressive strain at the ultimate strength level of any concrete under uniaxial pression is of the order of (see fig. 2), it would appear that a realistic prediction of the beam response under load cannot be based solely on the ascending portion of the uniaxial stressstrain relationship of concrete. In view of the above, the work described in the following appraises the widely held view that a uniaxial stressstrain relationship consisting of an ascending and a gradually descending portion is essential for the realistic description of the behaviour of a reinforced concrete beam in flexure. Results obtained from beams subjected to flexure under twopoint loading indicate that the large strains exhibited by concrete in the pression zone of the beams are due to a triaxial state of stress rather than the uniaxial postultimate stressstrain characteristics of concrete. It is shown that the assumption that the material itself suffers a pleteand immediate loss of loadcarrying capacity when ultimate strength is exceeded is patible with the observed ductile structural behaviour as indicated by loaddeflexion or momentrotation relationships. 2. EXPERIMENTAL DETAILS . Specimens Three rectangular reinforced concre
環(huán)評(píng)公示相關(guān)推薦
鄂ICP備17016276號(hào)-1