Microstructural analysis of plates with large strains as a result of central localised blast loading

The defonnation response and subsequent tearing of built in plates subjected to central impulsive loading has been investigated experimentally in the past. Theoretical predictions of the structural response have also been made and compared to these experiments. In this thesis, a new method is developed whereby the strains within the defonned plates were measured using micrographs of the grain structure of the plate. The aim of the thesis was to gain a fuller understanding of the internal defonnation of blast loaded plate so as to enable more accurate theoretical predictions of plate defonnation and tearing. The dimensions of the grains of the plate material both in the virgin state and after defonnation were measured by image analysis of scanning electron micrographs. These measurements were processed and averaged at various points within the structure. This enabled the strain distribution throughout the defonned plate to be analysed. Tensile tests were undertaken in order to calibrate this method of strain measurement. The tests were arrested during the loading, after the specimen had undergone a known amount of strain. The strain measured from the microstructure was then compared to the strain measured during the tensile tests. The method was found to give a satisfactory measurement of the strain in the tensile tests.

Grantor dc:publisher.institution

Department of Mechanical Engineering

Year dc:date.issued

1999

Author dc:creator

• Smith, Michael Philip

Advisor dc:contributor.advisor

• Nurick, Gerald N

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/11427/9600

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/9600