Post Local Buckling Behavior and Ultimate Capacity of H–section Beam
Abstract This paper presents a study on the ultimate capacity (maximum strength and plastic deformation capacity) of a thin–walled H–section beam. An experimental study is adopted by subjecting beams under cyclic loading to a large range of deformations with large depth–thickness ratios, which are over or close to the limit value of the current standards. The objectives of the present paper are to reveal the post local buckling behavior and to propose a handy method to evaluate the ultimate capacity. Instead of the commonly used parameter of width and depth–thickness ratio, the normalized thickness ratio WF developed in this study based on the author's previous studies can be regarded as the major parameter to evaluate the ultimate capacity. The relationship between WF and ultimate capacity is examined. The improved criteria for assessing the maximum strength and plastic deformation capacity of an H–section beam is proposed using normalized thickness ratio WF and is shown to be in good agreement with the experiment results.
INTERACTIVE BUCKLING BEHAVIOR AND ULTIMATE LOAD OF I-SECTION STEEL COLUMNS
The paper is intended to present a numerical and experimental study on the local-overall interactive buckling behavior and ultimate load of I-section steel columns. The numerical method, named the finite strip plasticity coefficient increment initial stress method, is proposed to trace up the interactive buckling ultimate load-carrying capacity of thin-walled plate structures involved in elastic-plastic and large deflection. The detailed solution procedures based on the amended Newton-Raphson iteration technique are presented. The structure discretization degree is reduced by the finite strip method and the computing quantity of elastic plasticity is significantly decreased by means of the section plasticity coefficient concept. Parameters such as column slenderness, web and flange plate width-thickness ratio, welded residual stress, and load eccentricity are considered in this paper. The experimental results of 11 welded I-section steel columns with relatively large plate width-thickness ratio have been found to agree reasonably with the numerical predictions. The results have shown that the column failure brought about by local buckling, overall buckling, or local-overall interactive buckling, and the local buckling of component plates does not mean a complete loss of the load-carrying capacity of the column at once.
Complex thoracic vascular injury repair using deep hypothermia and circulatory arrest.
A 61-year-old man with a penetrating injury to the innominate artery, left common carotid artery, and left subclavian artery at their origins from the aortic arch with associated injuries to both innominate veins and an innominate artery to vein fistula after a single stab wound is described. The patient was managed successfully using cardiopulmonary bypass together with deep hypothermia and circulatory arrest. Presentation and management are discussed.