Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266315
Title: Dynamic inelastic response and failure of structural elements.
Author: Li, Qingming.
Awarding Body: University of Liverpool
Current Institution: University of Liverpool
Date of Award: 1997
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Abstract:
The dynamic shear response and failure of structural elements under transverse impact loads are studied in the present work. The dynamic shear response is one of the important response modes in structural elements under transverse impact loads, which may lead to various shear failures depending on the loading rates and intensities. Transverse shear localization phenomena, which are represented by a shear hinge, have been observed in several structural elements when subjected to transverse dynamic loading and are studied in this thesis. The features of a stationary shear hinge are illustrated using a rigid, perfectly plastic simplification. The dimensions of a shear hinge for several structural elements are estimated both theoretically and numerically. It is shown that there exists a fixed shear hinge length for a given two-dimensional structural element. The length of a shear hinge is determined by its bending and shearing properties which can be obtained from a quasi-static analysis. When the shear hinge length has been determined, the conventional rigid-plastic method can be used to calculate the shear strain and shear strain rate within the shear hinge during the shear response phase. These theoretical results are employed to model Menkes and Opat' s beam problem to find two possible failure mechanisms, i.e., ductile shear failure and adiabatic shear failure and the associated transition conditions. A double-shear beam(DSB) subjected to a transverse projectile impact is studied experimentally and numerically in order to provide a more fundamental understanding on the features of structural failure in a localised shear zone. Both ductile tensile failure and adiabatic shear banding failure are found in the shear notch section. An analytical model and FEM simulation are developed to predict the DSB response and failures. The theoretical background of the strain energy density failure criterion is discussed and verified in this problem. Among the failure criteria examined in the current study, the strain energy density failure criterion is observed to give reasonable predictions for the failure initiation.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.266315  DOI: Not available
Keywords: Structural engineering Structural engineering
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