Equivalent Flat Plate Models of Composite Floors

Author(s):  
T. Zheng ◽  
T. Ji
1974 ◽  
Vol 100 (3) ◽  
pp. 513-531
Author(s):  
C. Trevor Harnden
Keyword(s):  

2016 ◽  
Vol 79 ◽  
pp. 16-29 ◽  
Author(s):  
É.L. Oliveira ◽  
N.M.M. Maia ◽  
A.G. Marto ◽  
R.G.A. da Silva ◽  
F.J. Afonso ◽  
...  

Author(s):  
Phyo Myat Kyaw ◽  
Osawa Naoki ◽  
Gadallah Ramy ◽  
Tanaka Satoyuki

Abstract Welding is an effective method for joining metallic structures which are very common in the construction of ships and offshore platforms. However, welded joints are prone to fatigue failure under cyclic loading due to the associated high residual stresses. In order to assess the fatigue crack propagation (FCP) accurately, precise evaluation of stress intensity factors (SIFs) is a key parameter. The residual stress distribution on the crack face of welded joints is usually non-uniform and also depends on boundary conditions. Therefore, an efficient technique is required to calculate SIFs for welded joints under non-uniform stress distribution. In this study, SIFs of semi-circular surface cracked welded joints are calculated by using the influence function method (IFM). The IFM has been introduced as an efficient method to evaluate SIFs under arbitrary stress distribution. The influence coefficient databases (ICDB) are developed for welded joints and flat plate models using IFM in this study. As the crack face traction (CFT) integral is employed in this developed influence coefficients (IC), the SIFs given by IFM are more accurate compared to the previously established solutions without CFT-integral. The ICDB and SIFs evaluated by using welded joint and flat plate models are compared and discussed. This study reveals the difference between ICDB of flat plates and welded joints, and estimation error of calculated SIFs for welded joints by using flat plate ICDB.


Author(s):  
Giridhara Babu Yepuri ◽  
Felix Jesuraj ◽  
Suresh Batchu ◽  
Kesavan Venkataraman

The experimental investigation of adiabatic film cooling effectiveness is carried out on a flat plates with 4:1 scaled up hole geometries, similar to that of typical turbine nozzle guide vane film cooling holes. Under this study, three flat plate models are considered with the two rows of holes having circular, fan and laidback fan shapes arranged in a staggered manner. These flat plate models are generated using solid works design software and fabricated using low thermal conductivity nylon based material using RPT technique. The mass flow results indicated the average nominal coefficient of discharge for the cooling holes as 0.71, for all these three models based on the inlet hole area and length of the holes. The laterally averaged adiabatic film cooling effectiveness is found along the stream wise direction at a density ratio of 1.62 by varying the blowing ratio in the range of 0.5 to 2.5. The surface temperatures of the test models are captured using the infrared camera, to evaluate the film cooling effectiveness. The experimentally evaluated results shows that, there is no increase in cooling effectiveness for the blowing ratio of 2.0 to 2.5 in the stream wise direction up to the X/d of 25 and there is a marginal increase above the X/d of 25 in the cases of these type of two row circular and Fan shaped hole models. Where as in the Laidback fan shaped hole model, the increase in cooling effectiveness is found significant up to the blowing ratio of 2.5 in the considered range. From the comparative results of adiabatic film cooling effectiveness of these three models, the laidback fan shaped hole model shows the higher film cooling effectiveness than the circular and fan shaped holes model at all the considered blowing ratios.


Author(s):  
J. J. Johnson ◽  
P. I. King ◽  
J. P. Clark ◽  
A. T. Lethander ◽  
N. A. Posada

The following experimental work described here entails the investigation by infrared thermography (IRT) of full-scale flat plates intended to model the pressure side (PS) of a modern fully-cooled turbine inlet vane called the High-Impact Technologies (HIT) Research Turbine Vane (RTV). The imaging system is used to make detailed full-coverage, two-dimensional, steady-state measurements of flat plate surface temperature. The PS has a total of 282 film cooling holes including three rows of showerhead holes near the leading edge and a handful of rows downstream depending on the design. The flat plates precisely match the material, thickness, and cooling hole sizes on the RTV, however they are not intended to match the external pressure field or the characteristics of internal cooling beneath the airfoil surface. Surface temperature relative to individual trial freestream gas temperatures is reported for an uncooled plate, a plate with the baseline RTV cooling scheme, and for four different hole types on a plate with a 3D-optimized cooling array designed for the RTV in previous work using genetic algorithms and computational fluid dynamics (CFD). The four different cooling hole shapes tested on the downstream rows of the optimized array plates include cylindrical holes, fan-shaped holes, Vehr holes, and a new cooling hole called a mini-trench shaped (MTS) hole. Experimentation on flat plate models using infrared thermography provides large amounts of valuable data, is inexpensive and highly repeatable relative to large rotating blowdown rigs. The results provide key insights into the differences between full-PS film cooling performance on the plate versus the 3D RTV and suggests to designers the best cooling hole shape for the next build of the RTV which will soon be tested in a full-scale blowdown rig instrumented with heat flux gauges. Overall, results clearly corroborate how cooling was redistributed and improved over the PS of the RTV in the original computational design effort and suggest that certain hole shapes are best suited for certain locations on the flat plate models.


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