Current Issue : July - September Volume : 2018 Issue Number : 3 Articles : 6 Articles
This paper presents a numerical study of reduced beamsection (RBS) beams with vertical and horizontal stiffeners. For RBS beams,\nit is speculated that strength deterioration will be caused by lateral buckling and local buckling. Supplemental lateral bracing (SLB)\ncan prevent lateral buckling but not prevent local buckling in the RBS portion. In the previous research, the effect of vertical or\nhorizontal stiffeners in RBS portion was shown to restrain local buckling of the RBS portion. But RBS with vertical stiffeners causes\nstress concentration at flange, and strength of RBS with horizontal stiffeners is lower than RBS with vertical stiffeners. In this paper,\nvarious patterns of placing stiffeners at the RBS portion are presented. The effect of vertical stiffeners and horizontal stiffeners\narranged at the RBS portion is discussed based on length. It is confirmed that, without placing supplemental lateral bracing (SLB),\nvertical and horizontal stiffeners can delay the occurrence of local buckling and prevent stress concentration.Moreover, the strength\ncan be sustained above 0.8...
Projects in the construction industry are becoming increasingly large and complex, with construction technologies, methods,\nand the like developing rapidly. Various different types of information are generated by construction projects. Especially,\na construction phase requires the input of many resources and generates a diverse set of information. While a variety of IT\ntechniques are being deployed for information management during the construction phase, measures to create databases of\nsuch information and to link these various different types of information together are still insufficient. As such, this study aims\nto suggest a construction information database system based on BIM technology to enable the comprehensive management of\nsite information generated during the construction phase. This study analyzed the information generated from construction\nsites and proposed a categorization system for structuring the generated information, along with a database model for storing\nsuch structured information. Through such efforts, it was confirmed that such a database system can be used for accumulating\nand using construction information; it is believed that, in the future, the continual accumulation and management of\nconstruction information will allow for corporate-level accumulation of knowledge as opposed to the individual accumulation\nof know-how....
Under the condition of drying and wetting circulation, ordinary concrete, modified concrete containing fly ash, and doubleadmixture\nconcrete containing fly ash and polypropylene fiber were corroded in the solution of Na2SO4 and (NH4)2SO4.The sulfate\nconcentration of the solution was designed to be 1000 g/L. The compressive strength and splitting tensile strength of the concrete\nwere tested after different number of drying and wetting cycles (0, 2, 4, 6, 8, and 10). The results indicate that the strength of concrete\nincreases in the early stages of corrosion and decreases gradually later. The admixture significantly improves the resistance to sulfate\nerosion of the modified concrete, while polypropylene fiber plays a less important role on anticorrosion properties. When suffered\n10 times of drying and wetting cycle, the compressive strength and splitting tensile strength of modified concrete increase by 28% and\n19%, respectively. Based on the test results, the service life of the modified concrete corroded by sulfate was predicted....
The purpose of this paper is to provide a comprehensive report on the state of the art on\nthe technologies used in the modeling of energy storage systems by latent heat in buildings, and\ndraw lines on perspectives on the technology evolution in this sector. In the first part, the emphasis\nis put mainly on the two main lines of research: experimental and numerical. In the second part,\nthe main trends of research in this sector have been followed. An anatomical operation of more than\n100 documents (published between 2006 and 2016), on the behavior of storage systems integrating\nPhase Change Materials (PCM), covering a large number of configurations treatment and their\napplications in thermal comfort of buildings area, has shown that the information published in this\ntopic are very diverse and enormous, but in many cases are insufficient. The results show that, with\nsuitable design, the PCM can contribute to the reduction of costs and achieve energy reductions in\nbuildings, guaranteeing a comfortable interior environment. The evaluation of this multitude of\ndocuments gave the following remark: The effectiveness of any proposed approach to a numerical\nstudy is a concept with ambiguities, depending upon the method used, its precision, the problem to\nbe modeled, the convergence criteria and the input parameters choice. The diversity of experimental\nconditions and the variety of results revealed that the published works are not directly comparable....
There are two different types of cruciform members used in practice. Flanged cruciform sections are typically fabricated from two\nhot-rolled WT sections welded to the web of a standard hot-rolled I section, whereas plain cruciform sections are typically\nfabricated from two symmetric rectangular plates welded in the form of a cross. Cruciform members that are subjected to\ncombined compression and bending are typically limited by torsional buckling unlike conventional compression members (such\nas W-shapes) that are typically limited by flexural (Euler) buckling about their local weak axis of bending. Detailed guidance on the\nanalysis of flanged and plain cruciform members is scarce in literature. Hence, this paper presents numerical studies on the\nstrength capacities of both flanged and plain cruciform members that are subjected to combined compression and bending effects.\nAnalysis results show the ability of flanged and plain cruciform to resist lateral-torsional buckling over longer unbraced lengths,\nallowing development of efficient plastic resistance...
It has been widely recognized that the constitutive model plays an essential role in engineering application of high ductile fiberreinforced\nconcrete (HDC). In this research, uniaxial compressive tests were conducted on nine groups of HDC specimens with\ndifferent mixture ratios and one group of mortar matrix specimens as comparison, discussing the effect of fiber content, watercement\nratio, fly ash content, and sand-binder ratio. According to the characteristics of stress-strain curve of HDC under uniaxial\ncompression, a damage constitutive model was proposed by introducing two damage threshold parameters and then was\ncompared with other existing models. Results indicated that the damage model curves suggested in this paper were best consistent\nwith experimental curves and substantially demonstrate the damage evolution process as well as the cracking resistance effect of\nfiber bridging stress....
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