The Effects of Plate-Support Condition on Buckling Strength of Rectangular Perforated Plates under Linearly Varying In-Plane Normal Load
— Mechanical buckling analysis of rectangular plates with central circular cutout is performed in this paper. The finite-element method is used to study the effects of plate-support conditions, aspect ratio, and hole size on the mechanical buckling strength of the perforated plates subjected to linearly varying loading. Results show that increasing the hole size does not necessarily reduce the mechanical buckling strength of the perforated plates. It is also concluded that the clamped boundary condition increases the mechanical buckling strength of the perforated plates more than the simply-supported boundary condition and the free boundary conditions enhance the mechanical buckling strength of the perforated plates more effectively than the fixed boundary conditions. Furthermore, for the bending cases, the critical buckling load of perforated plates with free edges is less than perforated plates with fixed edges.
ANALYSIS OF COMPOSITE WING SPAR WITH CUTOUTS FOR TENSILE LOAD
The use of composites in aircraft structures is steadily increased and now become part of daily life. In construction of multi-cell aircraft wing, cutouts are commonly provided in the wing spars and ribs to facilitate the fuel transfer across cells. While the web of the spar is expected to transfer shear loads under an overall bending load, presence of such discontinuities are of great concern. In particular, wing spars made of fiber reinforced composites, such discontinuities may result in fiber tear and are well known locations of stress concentration. Present work attempts to analyze a carbon fiber composite (CFC) and Glass fiber composite wing spar, with cutouts, under cantilever beam conditions with the tension load applied at one end of the spar to induce a pure bending stress at the cutout, through FE analysis. The data measured extensively during the tests was employed for varying thickness and diameter to identify the stress concentrations, critical failure locations. This study is to establish the need for modeling the whole loading assembly to achieve the results.
Laminar heat or mass transfer in rectangular channels and in cylindrical tubes for fully developed flow: comparison of solutions obtained for various boundary conditions
Abstract A comparison is made of results obtained with various boundary conditions at the wall of the channels. By comparing blood Sherwood numbers for finite wall resistance with those for constant concentration boundary condition only a small variation is found for various points along the blood channel.