Influence of imperfections on the out-of-plane flexural strength of post-tensioned masonry walls

2013 ◽  
Vol 41 ◽  
pp. 942-949 ◽  
Author(s):  
Jennifer R. Bean Popehn ◽  
Arturo E. Schultz
2017 ◽  
Vol 136 ◽  
pp. 245-260 ◽  
Author(s):  
Reza Hassanli ◽  
Mohamed A. ElGawady ◽  
Julie E. Mills

Author(s):  
Elena Ferretti ◽  
Giovanni Pascale

The purpose of this study is to improve the performance of walls under out-of-plane loads, particularly when subjected to the hammering action of the floors. The idea behind the paper is to provide the masonry walls with a device that behaves like a buttress, without having to build a traditional buttress. The solution presented here consists of a mechanical coupling between the three-dimensional net of steel ribbons of the CAM system and the CFRP strips. Since the steel ribbons of the CAM system have a pre-tension, the mechanical coupling allows the steel ribbons to establish a semi-rigid transverse link between the CFRP strips bonded on two opposite sides of a wall. Therefore, two vertical CFRP strips tied by the steel ribbons behave like the flanges of an I-beam and the flexural strength of the ideal I-beam counteracts the out-of-plane displacements of the wall. The experimental results showed that the combined technique inherits the strong points of both constituent techniques: the delamination load is comparable to that of the specimens reinforced with the CFRP strips and the overall behavior is ductile as for the specimens reinforced with the CAM system. They also allowed us to design a more performing combined technique.


2016 ◽  
Vol 857 ◽  
pp. 267-272
Author(s):  
Samih Abbas ◽  
K.P. Saji

Moderate to strong earthquakes can cause considerable damage to masonry walls which are primary structural elements for decades. In previous earthquakes, a large number of masonry walls failed due to insufficient shear strength with excessive in-plane deformation, or due to insufficient out-of- plane bending capacity of the walls in the perpendicular direction. Typically, out-of- plane failure is far more prevalent and happens earlier than in-plane failure in most past earthquakes. Thus their arises the need to strengthen this masonry walls. Generally, the compressive forces that masonry walls bear vary at different storey’s vary , therefore, walls at lower storey’s can only be applied with relatively smaller prestress due to already higher compression stresses produced by self-weight and floor dead load. Many strengthening methodsSuch as using NSM-CFRP, post tensioning, shortcreting etc. are excellent methods of strengthening masonry walls. In this the performance of post tensioned and reinforced masonry walls is analyzed. Ungrouted, partially grouted, and fully grouted Post Tensioned [PT] Masonry Walls exhibit different behavior and failure mechanisms. For this an analytical model based on an experimental study is prepared and their results are compared with ABAQUS.


2021 ◽  
Vol 243 ◽  
pp. 112683
Author(s):  
Jamiu A. Dauda ◽  
Luis C. Silva ◽  
Paulo B. Lourenço ◽  
Ornella Iuorio

2021 ◽  
Vol 8 (1) ◽  
pp. 130-136
Author(s):  
Roberto Spagnuolo

Abstract The stability check of masonry structures is a debated problem in Italy that poses serious problems for its extensive use. Indeed, the danger of out of plane collapse of masonry walls, which is one of the more challenging to evaluate, is traditionally addressed not using finite element models (FEM). The power of FEM is not properly used and some simplified method are preferred. In this paper the use of the thrust surface is suggested. This concept allows to to evaluate the eccentricity of the membrane stresses using the FEM method. For this purpose a sophisticated, layered, finite element with a no-tension material is used. To model a no-tension material we used the smeared crack method as it is not mesh-dependent and it is well known since the early ’80 in an ASCE Report [1]. The described element has been implemented by the author in the program Nòlian by Softing.


Sign in / Sign up

Export Citation Format

Share Document