טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentElmalich Dvir
SubjectAnalysis of Masonry Arches Strengthened with Composite
Materials
DepartmentDepartment of Civil and Environmental Engineering
Supervisor Professor Oded Rabinovitch
Full Thesis text - in Hebrew Full thesis text - Hebrew Version


Abstract

The research deals with the behavior of masonry arches strengthened with composite materials. A literature survey that opens with experimental studies that reveal the response of the strengthened structure and the unique phenomena involved is presented. These works highlight the contribution of the strengthening system and the role of the localized effects in its response. A survey of the existing theoretical studies shows that the main focus is on the global effects. The thesis aims to describe the global and the local nonlinear response of the strengthened masonry arch. The first step of the research focuses on a strengthened monolithic and elastic arch. A high-order linear elastic analytical model applicable to concrete chimneys, pipelines, silos, etc., is presented in two equivalent forms. The capabilities of the model are presented via a numerical study of the contribution of the strengthening system, especially in cases a hinge is formed, and the development of stress concentrations near the irregular points. To overcome the numerical difficulties due to the scale differences between the existing and the supplemental components, the second step formulates a unique finite element for the strengthened arch. The finite elements solution is compared with the solution of the strong form and through evaluation of the strain energy. The model is applied to a pseudo-nonlinear analysis of a masonry arch with an iterative simulation of the cracking. The study shows that a segmented strengthening system applied to the tensed face of the arch provides an alternative load bearing mechanism. On the other hand, it is involved with stress concentrations near the irregular points. The third step of the research formulates a unique nonlinear finite element model as a platform for the nonlinear analysis of masonry structures. The nonlinear response of masonry arches strengthened with composite materials is then studied, revealing different trends in the non linear response. A comparison with experimental results taken from the literature highlights some of the capabilities of the model and designates directions of additional improvement. The analysis reveals the capabilities of the strengthening system in to controlling the cracking at the joints. Yet, it also highlights the effect of debonding of the strengthening system. In conclusion, the research sets a basis for the analysis of strengthened curved masonry structures, highlights critical aspects of their response, and provides a platform for future augmentation to include geometrical nonlinearities, dynamic effects, and fracture mechanics assessment of the debonding process.