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Steel-coped beams are used in industrial structures to accommodate a cluster of water mains, fire hydrants, power cables and telecommunication wires. The coped regions restrict the ultimate capacity and cause unfavorable failure modes. The current study investigates the structural assessment of the coped section in offshore topsides while their use enhances operational safety for drilling and production. The structural evaluation is done through 2D digital image correlation (DIC) experiments to quantify the influence of various cope geometries. The DIC technique illustrated the strain and deformation measurements under different loading conditions for different coped geometry. The primary failure mode observed in local web buckling is characterized by noticeable lateral displacement and the development of buckling lines over the coped web. Studies showed the influence of the cope depth on the load-carrying capacity and buckling processes for different cope geometries. The results of the DIC analysis are strongly aligned with experimental data and finite element numerical results, suggesting this technique to the structural assessment of coped section. [ABSTRACT FROM AUTHOR]

In this paper, the vibration and buckling behavior of a functionally graded piezoelectric porous cylindrical microshell under thermo-electro-mechanical loads are explored on the basis of modified couple stress theory and higher-order shear deformation theory. First, the model of a functionally graded piezoelectric porous cylindrical microshell composed of piezoelectric materials with gradient change in the thickness direction was described. Second, the governing equations of the microshell were derived by Hamilton's principle and Maxwell equation. Third, the modal frequency and buckling equations of the microshell with simply supported ends were obtained on the basis of harmonic trigonometric functions. Finally, the effects of parameters on the modal frequency and buckling behavior were carried out by case studies. The results show that the modal frequency of the microshell can be adjusted by changing the porosity volume fraction, power index, applied voltage, axial load and geometric dimensions. It is also found that the vibration of the microshell is suppressed by positive voltage and axial compression but is strengthened by negative voltage and axial tension, and the material length scale parameter increases stiffness. In addition, the effects of applied voltage and axial load on the buckling behavior are larger than those of temperature. Results can be used to guide the design and application of piezoelectric devices. [ABSTRACT FROM AUTHOR]