Rotter, J. Michael

Chen, Jian-Fei

Batikha, Mustafa

Damascus University

2010-10-18T14:33:46Z

2010-10-18T14:33:46Z

2008

Steel silos are widely used as long-term or short-term containers for the storage of granular solids, of which a huge range are stored, from flour to iron ore pellets, coals, cement, crushed rocks, plastic pellets, chemical materials, sand, and concrete aggregates. The radius to thickness ratio for silos is in the range of 200 to 3000, so they fall into the category of thin shells, for which failure by buckling is the main concern and requires special attention in design. The primary aim of this thesis is to investigate the possible application of Fibre Reinforced Polymer (FRP) as a new repair and strengthening technique to increase the buckling capacity of thin metallic cylindrical shells. Extensive research has been conducted on the use of fibre reinforced polymer (FRP) composites to strengthen concrete, masonry and timber structures as well as metallic beams. However, all these studies were concerned with failure of the structure by material breakdown, rather than stability. As a result, this thesis marks a major departure in the potential exploitation of FRP in civil engineering structures. Many analyses of cylindrical shells are presented in the thesis. These are all focussed on strengthening the shell against different failure modes. Two loading conditions were explored: uniform internal pressure accompanied by axial load near a base boundary, and axial loads with geometric imperfections. For the latter, local imperfections are usually critical, and two categories of imperfection were studied in detail: an inward axisymmetric imperfection and a local dent imperfection. For the first loading condition, which leads to elephant’s foot buckling, an analytical method was used to derive general equations governing the linear elastic behaviour of a cylindrical shell that has been strengthened with FRP subject to internal pressure and axial compression. It was used to identify optimal application of the FRP. All the later studies were conducted using nonlinear finite element analysis (using the ABAQUS program) to obtain extensive predictions of many conditions causing shell buckling and the strengthening effect of well-placed FRP. In all the cases studied in this thesis, it was shown that a small quantity of FRP composite, applied within a small zone, can provide a significant enhancement of the resistance to buckling failure of a thin metal cylinder. These calculations demonstrate that this new technique is of considerable practical value. However, it is clear that not all the relevant questions have been fully answered, so the author poses appropriate questions and makes suggestions for future work.

http://hdl.handle.net/1842/3994

en

The University of Edinburgh

Batikha M, Chen JF and Rotter JM (2007). “FRP strengthening of metallic cylindrical shells against elephant‘s foot buckling.” Proc. of the Conference on Advanced Composites in Construction, ACIC 07, 2-4 April, Bath, UK, 157-164.

Batikha M, Chen JF and Rotter JM (2007). “Numerical modelling of shells repaired using FRP.” Proc. of the 3rd International Conference on Steel and Composites Structures, ICSCS 07, 30 July-1 August, Manchester, UK, 1065-1069.

Batikha M, Chen JF, Rotter JM (2007). “Elastic buckling of FRP-strengthened cylinders with axisymmetric imperfections”. Proc., Asia-Pacific Conference on FRP in Structures, APFIS 2007, 12-14 December, Hong Kong, 1011-1016.

Batikha M, Chen JF, Rotter JM (2008). “Strengthening metallic shells with FRP against buckling”. Proc. of the 4th International Conference on FRP Composites in Civil Engineering, CICE 2008, 22-24 July, Zurich, Switzerland, accepted.

stengthening

buckling

cylinder

shells

metal

Fibre Reinforced Polymer

Strengthening of thin metallic cylindrical shells using fibre reinforced polymers

Thesis or Dissertation

Doctoral

PhD Doctor of Philosophy