حيدر زهير عبد الامير زيني

Stepped or non-prismatic beams are widely used in many engineering applications and the calculation of their natural frequency is one of the most important problem. Several methods were used to calculate the natural frequency of stepped beam. In this work, the Rayleigh methods (Classical and Modified) and finite element method using ANSYS software were used for calculating the natural frequency of Hollow stepped cantilever beam with circular and square cross section area

Analytical and numerical approaches for calculating the static deflection of functionally graded beam under mechanical load

Experimental investigation has been carried out to study the effect of induced vibration of a simply supported on the heat transfer process in the simultaneously developing of hydrodynamic and thermal boundary layer region of a concentric vertical annulus with uniformly heated outer cylinder and rotating solid inner cylinder. The experimental setup consists of an annulus which has a radius ratio of 0.365 and outer cylinder with a heated length 1.2 m subjected to the constant heat flux. The investigation covers Reynolds number (Re) range from 514 to 1991, Taylor number (Ta) values are 10.44 104 & 82.23 104, heat flux varied from 468 W/m2 to 920 W/m2 and frequency (Fr) values are 32 & 77 Hz. Results showed for all frequency values which that the local Nusselt number values increase as the heat flux increases when the value of frequency near the natural frequency and the value of surface radiation decrease. Correlation equations have been deduced to calculate the rate of heat transfer, represented by the average Nusselt number (Num) as a function of (Ta), (Ra) and (Fr). A comparison has been made between the present work and the previous works for temperature and local Nusselt number variations and it has given a good agreement.

In this work, functionally graded Materials (FGMs) were created by centrifugal force mixing polyester resin with silicon dioxide (SiO2) to create five layers, each having a thickness of 1.2 mm. Tensile composite specimens with varying volume fractions (0, 10, 15, 20, 25, and 30)% are taken before the fabrication of the FGMs specimens, and their modulus of elasticity is subsequently computed. The fourth specimen was made using the exponential equation to describe the property distribution throughout the thickness of the three-points specimen, whereas the other three specimens were made using the power law equation when the power law index (β) was (0.5, 1, and 5). Flexural modulus of the functionally graded composite (FGMs) loaded from the neat polyester, raised by 37.1% for (β=0.5). When compared to pristine polyester, the flexural modulus improved by 33.3% for (β=1). The increase in (β=5)'s flexural modulus was (27.78%). The flexural modulus improved by 24.5% with exponential FGMs.Good correlations are observed, with the greatest absolute discrepancy between the numerical and experimental outcomes being 14.6% when the power law index (β) is at (0.5).The results of the experimental flexural test were verified using Design Modeler (ANSYS Workbench R2 2021).

In the current research, the static deflection of the pre-twisted beam has been calculated experimentally and numerically using finite element approach (ANSYS workbench 2020R1) and under the effects of different twist angles, different lengths, four boundary conditions of edges support of the beam. The beam was manufactured from PETG filament material by a 3D printer at room temperature. The obtained results showed reasonable acceptance between the experimental and numerical pre-twisted beam deflection. The numerical maximum deflection of the pre-twisted beam decreased with the increase of twisted angle of the beam for clamped-simply and simply-simply edges support. While it was irregularly various for clamped-clamped edge support with a minimum value of the maximum deflection occurred at the twist angle 135o. The maximum deflection of the pre-twisted beam is disappeared gradually at the twist angles greater than 270o for claimed-free edge support. In addition, the maximum deflection of the pre-twisted beam increased due to the beam length increment.