Thesis (M.S.)--Missouri University of Science and Technology, 2010. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed July 26, 2010) Includes bibliographical references (p. 58-59).

Thesis (Ph.D.)--Aberdeen University, 1989. / Title from web page (viewed on Mar. 4, 2010). Includes bibliographical references.

Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references (leaves 107-108). Also available on the Internet.

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: Case Studies, Steel, Fire. Includes bibliographical references (p.146-147).

Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references (leaves 107-108). Also available on the Internet.

Thesis (Ph. D.)--Lehigh University, 2000. / Includes vita. Includes bibliographical references (leaves 124-128).

The contribution of the clamping force in the technique used in this study to stretch-bend low carbon steel samples was investigated to support the subsequent changes in the microstructure and properties of the formed material with regard to parent material. Although plastic deformation by cold working is known to induce texture or preferred orientation to the grains of a formed material while decreasing its ductility and increasing the strength, as well as inducing residual stress, it is not known how the different directions (rolling, transverse and oblique/45°) of the sheet steel will respond to this stretch bending technique. The first part of the research work involved a thorough literature review on sheet metal forming processes and their effect on the formed material with interest on the above mentioned directions of the sheet. It became clear from the literature overview that cold working of a material will induce strain-hardening which varies with the magnitude of cold work, resulting in changes in the strength and ductility of the material. Besides, when plastic deformation is not uniform (e.g., tensile and compressive) throughout the entire cross section of the formed part, residual stresses remain in the material with the grains been elongated along the direction of the maximum strain. The main parameters that were considered and controlled in this study are as follows: strain experienced / stress induced into the form sample, the sample direction, the stroke length and the clamping torque, the generated radius of curvature. The chapters that follow the literature review, deal with the set-up of the different equipment used in this study, the specimen preparation as well as the recording, the calculation and interpretation of the results. It was found that the stress magnitude that generated the different radii of curvature (120 mm, 150 mm and 185 mm) was between 1 percent & 13 percent higher than the parent material’s yield strength with the lower stress been associated to the smaller radius of curvature and the higher stress to the higher radius. The stress induced into the sample during forming was not only proportional to the stroke length but also to the distance between the punch’s tip and the sample and the sample to the die’s nadir. The clamping torque adopted was restricted to the manual capacity of the operator who used a preset torque wrench to fasten the plate sample into the jig. Plate samples of low carbon steel were cut to angles of 0°, 45°, and 90° to the rolling direction of the sheet material and stretch-bent on a single-action mechanical press to 120 mm, 150 mm, and 185 mm radii of curvature. The preliminary results indicate that stretch-bent samples had increased hardness to the parent plate, in particular below the surface layers up to around 1.1 mm depth. Since there is a well established relationship between hardness, yield and tensile strengths for steel, the yield and tensile strengths of the formed material were estimated using the Nobre et al [34] incremental relation, which relates the linearity between relative increments of hardness and yield strength. Changes were not noticeable at the microstructural level of the formed samples. Meanwhile, samples from which higher plastic deformation stress values were calculated were not those absorbing higher impact energy when Charpy specimen cut from plate and stretch-bent samples were tested. The maximum relieved residual stress in the parent material was predominantly compressive and represents in magnitude approximately 12 percent (average for the three directions) of its original yield strength. In the stretch-bent samples, the relieved residual stress was compressive in the outer curved section with a magnitude about 50 percent of the parent material yield strength and tensile in the inner curved section with a magnitude approximately 25 percent of the parent material yield strength.

M.Ing. / Design parameters for ferritic type stainless steel structural members do not exist and is needed. This study attempts to find design parameters for ferritic type stainless steel compression elements. The ferritic type stainless steel under consideration in this study is Type 3CR12 corrosion resisting steel, which is a modified Type 409 stainless steel. The purpose of this study was to determine the limiting web width-to-thickness and flange width-to-thickness ratios for the prevention of local buckling in axially loaded hotrolled Type 3CR12 corrosion resisting steel columns. Experimental data was obtained in an ongoing study on the limiting width-to-thickness ratios for elements in compression. No conclusion on this aspect can be reached at this stage of the investigation

This research into the properties of a 5"x5"x16lb W.F., A 36 Steel, rolled structural member was undertaken to determine the following: i - Yield stress distribution over the cross section of the member as determined by coupon tests. ii - Development of strain over the cross section of the member, as measured by electric strain gauges, when subjected to a) Axial loading, b) Bending Moment. iii - The effect of previous loading of a member as a column into the region of yielding on its subsequent behaviour as a beam loaded to failure. The following results were obtained: i - Yield stress, particularly the upper yield stress was not uniform over the cross section. ii - The strain distribution in the plastic range was not uniform and varied from cross section to cross section and even at closely adjacent points on the same cross section. iii - Failure of the member, due to inadequate lateral support when loaded as a column, occurred before complete yielding was achieved. The effect of this previous loading on the subsequent behaviour of the member as a beam loaded to failure was inconclusive. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

This is an experimental study of the plastic yielding of steel columns. It consists of tests of four specimens; two tension coupons, a 12-inch stub column and a 21-inch stub column. The tension tests were used to determine the physical properties of the material while the stub columns demonstrated the effects of residual stress upon the initiation of yielding and the propagation of the yielding. The test procedure used in both the tension tests and the compression tests was the same. The specimen was loaded in increments up to a load just, below the yield point. Beyond that point the specimen was strained at a constant rate in order to neutralize the effects of creep. This test procedure required that all the data for each set of readings be adjusted to give the strain at any gauge on the specimen at the same instant of time. This was done by considering the differences between consecutive sets of readings and adjusting all strains to the strain at the gauge showing the greatest change during the set. This was done by means of a computor [sic] program. During the tests of the stub columns local buckling of the flanges and web was restrained by a system of bars and bracing frames. The system used in the test of the 21-inch stub column proved to be particularly successful. Data was collected from strain gauges in the tension tests and strain and dial gauges in the compression test. The dial gauges in the compression test provided confirmation that the strain gauges accurately represented the state of strain in the specimens and also rotation of the upper end of the stub columns during the tests. There are several general conclusions which, it must be emphasized, are based upon a small number of tests. The yield stress of the tension specimens was greater than of the compression specimens. Yielding initiates at several independent foci rather than propagating from one single point. Yielding, once commenced, generally continued without stopping well into the strain hardened region. Therefore, there are both unyielded material and strain hardened material in the specimen at the same time. The initiation and progress of plastic deformations in the specimen are greatly affected by even small local irregularities. The effect of residual stresses upon the initiation of yielding is not uniform. The strain hardening modulus of the specimens used has been found to be only about one-half of that expected. Wide variation of this property is common. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate