An analytic solution to a particular boundary value problem in linear elasticity is presented. The problem considered is that of a circular disc, in plane strain or generalized plane stress, which is loaded quite generally at the perimeter by a set of self equilibrating forces. The disc has a radial crack extending completely from the centre to the perimeter. Three particular load cases are considered: the disc is loaded by uniform radial tension; the disc is pulled by two diametrical concentrated loads with line of action perpendicular to the crack; the disc is pulled by two concentrated forces acting at the mouth of the crack. In each case the stress intensity factor is evaluated and contours of the isochromatics are presented in dimensionless form. The results agree with those derived by other workers but the method presented here is more general, more efficient, and extends the previous results for finite bodies containing cracks. The three load cases have also been applied to the disc when the tip of the crack has been removed by the presence of a concentric hole. New results are presented for the stress concentration factors for a full range of geometric parameters. Finally it is shown how the second and third of the load cases may be used for controlled laboratory tests in the study of fracture and fracture toughness of brittle materials. / Applied Science, Faculty of / Mechanical Engineering, Department of / Graduate

No description available.

In the past riveting was commonly used for connecting steel structures, such as bridges. These fasteners usually develop a low and unreliable level of pretension such that the joints are assumed to behave like bearing type connections. Under cyclic loading, and depending on the stress concentration around the fastener holes, fatigue failure can occur at nominal stresses significantly lower than in members with no stress concentration. The current design standards account for this by calculating the stress range on the net section and using fatigue category B and D to assess the fatigue life for bolted and riveted details respectively. The net area used for the calculation of the stress range is based on the procedure proposed by Cochrane (the s2/4g rule), which is adequate shear type failure. Tests have shown, however, that the Cochrane approach does not apply for fatigue failure since rupture does not take place in a ductile shear mode. An investigation into the effect of connection size and hole pattern on the fatigue resistance of built-up I section to gusset plate connections was carried out. A design equation that considers the connection size and hole layout on the stress concentration factor is proposed. An appropriate fatigue category for these members is also recommended. / Structural Engineering

No description available.

No description available.

Thesis (M.S.)--Ohio University, August, 1993. / Title from PDF t.p.

Thesis (Dr. techn. Wiss.): Kgl. Technischen Hochschule zu Müchen, 1912. / eContent provider-neutral record in process. Description based on print version record.

The positions of high stress concentration in a bicycle frame structure made in composite materials and a way to strengthen them were investigated via SolidWorks and ANSYS, 3D picture plotting software, and numerical simulation software, respectively. The capability of productivity will be improved indirectly due to the shortening of the time in the process of customers¡¦ order, research, development and mass production. In experiment, prepreg tape (TOHO UT500 carbon fiber/AD. Group matrix) which were produced by AD. Group were made into laminates by hot-pressing machine. The material constants of the laminate and the stress-strain diagram were obtained according to the stander of ASTM D3039. The received material constants are E11 =151.55 GPa and E22 = 7.654 GPa, respectively. In simulation, the experimental data E11 and E22 were used in the numerical analysis, and obtained the stress and deformation fields of the bicycle frame structure and the front fork were plotted based on the standards provided by AD. Group. Reinforcements were made according to the positions of stress concentration in the diagrams. The results of improvements of the front fork after reinforcement include¡G the deformation of normal rigidity was improved to 9.45mm from 12.89mm, and the lateral deformation was significantly improved to 0.97mm from 13mm. Other improvements of the frame structure after reinforcement contain the deformation: dual-side rigidity was improved to 6.6mm from 11.7mm, and the deformation of single-side rigidity was improved to 12.5mm. The rigidity of the head lug was 0.46mm and there is no need to reinforce it because it was meets requirements. Keywords: Numerical analysis, bicycle frame, prepreg, stress concentration.

published_or_final_version / Mechanical Engineering / Master / Master of Philosophy

Thesis (M. Eng.)--Carleton University, 1988. / Also available in electronic format on the Internet.