Stochastic and Statistical Analysis of Structural Resistance and Material
Kolawole Abejide; Jubril Kaurra Mohammed; A. Lawan; Olugbenga Samuel Abejide
Abstract
This study presents the structural reliability of rolled steel beams on offshore platforms exposed to corrosion during their design period and beyond. The rate of corrosion of the rolled steel beam was determined using a standard expression for extreme marine environment. Limit equations were used to ...
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This study presents the structural reliability of rolled steel beams on offshore platforms exposed to corrosion during their design period and beyond. The rate of corrosion of the rolled steel beam was determined using a standard expression for extreme marine environment. Limit equations were used to evaluate the shear performance, deflection, and resistance moment of the rolled steel beams during their design period. The exposure to corrosion was evaluated using the First Order Reliability Method (FORM) in MATLAB with FERUM Version 4.0 (Finite Element Reliability Using Matlab). An increasing decline in the shear, resistance moment, and deflection was observed as the cross sectional area decreased due to corrosion, which is consistent with experimental data. However, it was also noted that the design formulation is robust enough to exceed the design life prediction in the code.
Probabilistic Design Approaches
A. Mustapha; Olugbenga Abejide
Abstract
The profound changes in engineering over the last few decades were reflected by ideas of uncertainty recognized in engineering today. Civil engineering structures like steel transmission poles are to be designed for loads created by environmental actions such as wind, snow and earthquake, but these actions ...
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The profound changes in engineering over the last few decades were reflected by ideas of uncertainty recognized in engineering today. Civil engineering structures like steel transmission poles are to be designed for loads created by environmental actions such as wind, snow and earthquake, but these actions are exceptionally uncertain in their manifestations as one is required to quantify the risks and benefits involved. The subject of structural reliability offers a rational framework to quantify uncertainties mathematically. This study presents a probabilistic assessment of the strength of steel poles in service, the resistance of the steel poles, ultimate strength of steel, section modulus, cross sectional dimensions of the poles, distance at which the load acts on the pole and the magnitude of the load acting on the pole are treated as random variables, which can be significantly influenced by time and location. The study has been carried out to determine the structural safety levels of electric distribution steel poles under uncertain loadings using First Order Reliability Method (FORM) in MATLAB with FERUM Version 4.0. The reliability analyses in MATLAB gave lower values of reliability index, (1.4802E+00) and probability of failure (6.9407E-02) for moment failure mode, while higher values of (2.339E+01 and 5.1245E+01) were obtained respectively for deflection and shear failures, with negligible values of 0.100E-10. The effect of variation of parameters like thickness, diameters and length of steel poles were also studied, which indicates that the thickness, diameters and length significantly affects the strength of steel poles.
