http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Deep-beams with indirect supports: numerical modelling and experimental assessment
Mário Pimentel,Paulo Cachim,Joaquim Figueiras 사단법인 한국계산역학회 2008 Computers and Concrete, An International Journal Vol.5 No.2
An experimental and numerical research was conducted to gain a deeper insight on the structural behaviour of deep-beams with indirect supports and to assess the size effects in the ultimate state behaviour. The experimental campaign focused on the influence of the reinforcement tie distribution height on the compression check of the support region and on the benefits of using unbonded prestressing steel. Three reduced scale specimens were tested and used to validate the results obtained with a nonlinear finite element model. As a good agreement could be found between the numerical and the experimental results, the numerical model was then further used to perform simulations in large scale deep-beams, with dimensions similar to the ones to be adopted in a practical case. Two sources of size effects were identified from the simulation results. Both sources are related to the concrete quasi-brittle behaviour and are responsible for increasing failure brittleness with increasing structural size. While in the laboratory models failure occurred both in the experimental tests as well as in the numerical simulations after reinforcement yielding, the numerically analysed large scale models exhibited shear failures with reinforcement still operating in the elastic range.
Moisés R. Cesário,Daniel A. Macedo,Rosane M. P. B. Oliveira,Patrícia M. Pimentel,Roberto L. Moreira,Dulce M. A. Melo 한양대학교 세라믹연구소 2011 Journal of Ceramic Processing Research Vol.12 No.1
Strontium-doped lanthanum manganite (La1−xSrxMnO3) is a commonly used cathode in solid oxide fuel cells. In this study,La0.80Sr0.20MnO3 powder was prepared by the modified Pechini’s method using gelatin as the polymerizing agent. The polymeric resin obtained was characterized by thermogravimetric analysis and the powder calcined at 900 oC for 4 h has been characterized by X-ray diffraction, scanning electron microscopy and infrared spectroscopy. The La0.80Sr0.20MnO3 phase exhibited rhombohedral symmetry. The infrared reflectance spectrum was dominated by a conduction mechanism besides the signature of less pronounced phonon features, characteristics of the crystal lattice. The present results indicated that the gelatin has been an efficient directional element to be used in La0.80Sr0.20MnO3 synthesis, and it is a low cost material, non toxic and makes the polymeric precursor synthesis less complicated.