Thesis (doktor-ingenieur)--Sächsische technische hochschule, Dresden. / "Ueber einige von diesen versuchen wurde von herrn prof. Schwinning in einem vortrag auf der sitzung des kerbschlagausschusses des Deutschen verbandes für die materialprüfungen der technik am. 6. märz 1925 bereits kurz berichtet [Mitt. nr. 75 des D. v. m.]." "Literatur-verzeichnis": p. 98-99.

Thesis (doktor-ingenieur)--Sächsische technische hochschule, Dresden. / "Ueber einige von diesen versuchen wurde von herrn prof. Schwinning in einem vortrag auf der sitzung des kerbschlagausschusses des Deutschen verbandes für die materialprüfungen der technik am. 6. märz 1925 bereits kurz berichtet [Mitt. nr. 75 des D. v. m.]." "Literatur-verzeichnis": p. 98-99.

Dynamic wind tunnel tests were made on plunging rectangular cylinders with various depth to width ratios (b/h) and the results were compared with predictions based on the quasi-steady approach. To restrain the models to plunging oscillation they were attached, top and bottom, to transverse shafts guided by hydrostatic air bearings. An electromagnetic eddy current damping device was developed to obtain accurately calibrated viscous damping. Dynamic displacements were measured with a variable coupling electromagnetic transducer designed specifically for this apparatus. Direct force measurements were made for the square cylinder to obtain the lateral force variation with angle of attack in the Reynolds number range of the dynamic tests. The velocity-amplitude curves for those cylinders which oscillated are presented. The curves for b/h = 1.00 agreed with the predictions of the quasi-steady approach, and could be reduced onto one curve by using the ratios of applied damping. The longer rectangles did not prove to be amenable to analysis by the quasi-steady approach, and appeared to be strongly influenced by the instantaneous wake geometry. Rectangular cylinders of b/h over 4.00 did not plunge. Hot wire measurements showed that the Strouhal frequency was present in the wake of the plunging cylinder, occurring simultaneously with the plunging frequency. / Applied Science, Faculty of / Mechanical Engineering, Department of / Graduate

A simple method is presented, suitable for the repetitive testing necessary to investigate fully the bond characteristics in the anchorage zones of pretensioned pre-stressed members. Conditions in one anchorage zone of a member are simulated, the central zone of constant stress being replaced by a rigid steel frame. Loads in the wire on either side of the specimen are measured by load cells incorporating strain gauges. The experimental series comprised thirty specimens, of which five were prestressed with bright wire. Seventeen specimens were prestressed with rusted wire and the remainder were cast with rusted wire under zero prestress. The results show the superior anchorage characteristics of rusted wire over bright wire and the exponential nature of the load pickup of the wire in the anchorage zone. A relation is suggested between end pull in at the free end and ultimate load anchored. A short description of an investigation of the relaxation behaviour of prestress wires is appended to the thesis. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

Tension tests have been performed on LiF single crystals. The results of strain rate change tests are not wholly consistent with current theories of deformation processes. The number of mobile dislocations appears to depend sensitively on the stress prevailing during straining. A short investigation of the effect of removing surface layers during deformation was undertaken. The surfaces of chemically polished LiF single crystals are not sites of strong work-hardening. The effects of magnesium-rich surface layers on the mechanical properties of LiF have been studied. The yield stress, critical tensile stress, and work-hardening slope increase linearly with layer thickness, while the strain to fracture decreases rapidly with increasing layer thickness. The results of tension tests, supplemented by metallographic evidence, indicate that the yield stress and the critical tensile stress are not determined by surface source operation. / Applied Science, Faculty of / Materials Engineering, Department of / Graduate

published_or_final_version / Mechanical Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / Civil Engineering / Master / Master of Science in Engineering

published_or_final_version / Civil Engineering / Master / Master of Science in Engineering

Digitized by Kansas Correctional Industries

Digitized by Kansas Correctional Industries