NOPR Collection:

Behaviour of slurry infiltrated fibrous concrete (SIFCON) simply supported two-way slabs in flexure

2005-10-01T00:00:00Z

Title: Behaviour of slurry infiltrated fibrous concrete (SIFCON) simply supported two-way slabs in flexure Authors: Rao, H Sudarsana; Ramana, N V Abstract: Slurry infiltrated fibre concrete (SIFCON) is one of the recently developed construction material. SIFCON could be considered as a special type of fibre concrete with high fibre content. The matrix consists of cement slurry or flowing cement mortar. This composite material has already been used for structures subjected to blast loading, repair of pre-stressed concrete beams and safe vaults¹. This paper presents the information on behaviour of two-way slabs in flexure. Flexure and cyclic load tests have been conducted and compared with fibre reinforced concrete (FRC) and plain concrete slabs. Both strength and deflection characteristics have been studied. The results of the experimental investigation indicate that with 12% fibre by volume of matrix slabs possess excellent performance among other slabs in all respects. Page(s): 427-433

Interference effects on wind pressures on low-rise and high-rise square structures in side-by-side arrangement

2005-10-01T00:00:00Z

Title: Interference effects on wind pressures on low-rise and high-rise square structures in side-by-side arrangement Authors: Lakshminarasimhan, J; Gowda, B H Lakshmana; Sivannarayana, Ch Abstract: In this paper, the effects of interference on three-dimensional bluff bodies with square cross-section placed in side-by-side arrangement for a low-rise body and a high-rise body have been investigated experimentally. The extent of interference effects are brought out by varying the spacing between the bodies. The pressure distributions on the surfaces of the bodies are measured to bring out the severity of interference due to another body adjacent to it. The bodies are exposed to an air stream with a velocity profile satisfying the 1/7^th power law. It is seen that the pressure distribution on rear side and interference side is greatly affected for low-rise body when interfered by a high-rise body in close proximity. Page(s): 398-410

Flow analysis in a model can-type gas turbine combustor

2005-10-01T00:00:00Z

Title: Flow analysis in a model can-type gas turbine combustor Authors: Jain, Abhishek; Chaudhary, Sidharth; Singh, S N; Rai, Lajpat Abstract: Flow analysis has been carried out in a model can-type gas turbine combustor using a commercial computational fluid dynamics (CFD) code. The code has been validated against the experimental results quoted in the literature and part of the present study. The comparison has shown that CFD code can be effectively used to carry out parametric investigations on the complete combustor model for the combustor design. Page(s): 389-397

Long crack growth mechanisms in Ti-6Al-4V alloy

2005-10-01T00:00:00Z

Title: Long crack growth mechanisms in Ti-6Al-4V alloy Authors: Goswami, T Abstract: A transition mechanism of long crack growth from structure sensitive (Regime I) to insensitive region (Regime II) was investigated at (i) room temperature under high humidity conditions, and (ii) elevated temperatures for Ti-6AI-4V alloy and other materials. Constant amplitude tests were conducted using several stress ratios (R = 0.05, 0.1, 0.4 and 0.7) for the high humidity tests and 0.1 for room and elevated temperature tests. Conventionally forged Ti-6AI-4V alloy disks, processed to the solution treated and over-aged condition, were studied for both programs. An increase in stress ratio and temperature lowered the transitional stress intensity factor range where Regime I transitioned to Regime II. Higher stress ratios (R = 0.7) accelerated the fatigue crack growth rates many times the crack growth rates obtained at lower stress ratios (R = 0.05). However, higher temperatures (345°C) influenced the crack growth rates only marginally. The mechanisms controlling elevated temperature fatigue crack growth in Ti-6AI-4V were by the secondary crack formation, striations and some cavity features on the fracture surface. The damage was localized on the α platelets, where a type dislocations found with the Burgers vectors (a/2)<11 0> g = 1010 near (10 0). Page(s): 367-375