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.
Numerical analysis and geometric optimization of perforated thin plates subjected to tension or buckling
Thin perforated plates when employed in naval, marine and offshore structures are used as a way of access or to reduce the total weight of the structure. If these perforated plates are tensioned, regions of stress concentration are generated. If these panels are subject to a compressive load, the buckling phenomenon can occur. The objective of this paper was to perform a geometric optimization based on the Constructal Design method for these structural elements. The computational models were developed in the ANSYS software. The results indicated optimal geometries 2700 % and 74 % superior for tension and buckling applications, respectively.
New approach to vision-based BGA package inspection
Ball grid array (BGA) techniques have developed very fast due to the advantages of more I/O ports, small size, and so on. In this paper, a vision-based algorithm for BGA package inspection is proposed to accurately estimate center and diameters of solder-balls of BGA packages, so that defects of BGA packages, such as missing or extra balls, oversize or undersize balls, over-height or under-height balls, and pitch can be detected for ensuring the quality of BGA packages.