Study of the Compressive Strength of Aluminum Curved Elements

Currently, the Specification for Aluminum Structures (Aluminum Association, 2010) shows thin-walled aluminum plate sections with radii greater than eight inches have a lower compressive strength capacity than a flat plate with the same width and thickness. This inconsistency with intuition, which suggests any degree of folding a plate should increase its elastic buckling strength, inspired this study. A wide range of curvatures are studied—from a nearly flat plate to semi-circular. To quantify the curvature, a single non-dimensional parameter is used to represent all combinations of width, thickness and radius. Using the finite strip method (CU-FSM), elastic local buckling stresses are investigated. Using the ratio of stress values of curved plates compared to flat plates of the same size, equivalent plate-buckling coefficients are calculated. Using this data, nonlinear regression analyses are performed to develop closed form equations for five different edge support conditions. These equations can be used to calculate the elastic critical buckling stress for any curved aluminum section when the geometric properties (width, thickness, and radius) and the material properties (elastic modulus and Poisson’s ratio) are known. This procedure is illustrated in examples, each showing the applicability of the derived equations to geometries other than those investigated in this study and also providing comparisons with theoretically exact numerical analysis results.

An Analysis Of U.S.- Economic Policy Toward Chile During The Cold War

This examination of U.S. economic policy directed toward Chile centered on the political and economic changes that occurred within Chile between 1960 and 1988. During this time, U.S. economic policy directed toward Chile was crafted by members of the American government uneasy with Cold War concerns with the most important of which being the spread of Communism throughout the globe. By viewing U.S. policy toward Chile through this Cold War lens, this thesis explores the different ways in which economic policy was used to advance the political and economic goals within not only Chile, but also Latin America as a whole. The Cold Warriors that crafted and enacted these economic policies were motivated by a variety of factors, and influenced by events outside of their control. From President John F. Kennedy to Ronald Reagan, American policymakers utilized economic policy as a means to achieve regional goals. This project sheds light on an understudied section of U.S. foreign policy history by exploring the way that economic policy helped achieve Cold War objectives in the Southern Cone.