Tilting plane tests for the ultimate shear capacity evaluation of perforated dry joint masonry panels. Part I: Experimental tests

2021 ◽  
Vol 238 ◽  
pp. 112124
Author(s):  
Nicola Grillanda ◽  
Andrea Chiozzi ◽  
Gabriele Milani ◽  
Antonio Tralli
2021 ◽  
Vol 228 ◽  
pp. 111460
Author(s):  
Nicola Grillanda ◽  
Andrea Chiozzi ◽  
Gabriele Milani ◽  
Antonio Tralli

2020 ◽  
Vol 21 (5) ◽  
pp. 1777-1793
Author(s):  
Beatrice Belletti ◽  
Jesús Rodríguez ◽  
Carmen Andrade ◽  
Lorenzo Franceschini ◽  
Javier Sánchez Montero ◽  
...  

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Donia Salman ◽  
Rabab Allouzi ◽  
Nasim Shatarat

PurposeThe main goal is to investigate the effect of size and location of opening and column size on the punching shear strength. Openings are often needed in order to install mechanical and electrical services. This process takes away part of the concrete volume which is responsible for resisting the shear forces and any unbalanced moment. Furthermore, the application of rectangular columns in flat slabs is commonly used in practice as they provide lateral stiffness to the building. They are also utilised in garages and multi-storey buildings where these elongated cross-sectional columns reduce the effective span length between adjacent columns.Design/methodology/approachThis research is a numerical-based investigation that is calibrated based on a thirteen previously tested and numerically calibrated slab specimens with no openings. A parametric study is conducted in this study to consider the effect of other parameters, which are the size and location of opening and the rectangularity ratio of column in order to evaluate their effect on the punching shear capacity. A total of 156 models are developed to study these factors. Additionally, the predicted shear carrying capacity of the simulated slabs is calculated using the ACI318–19 and Eurocode (EC2-04) equation.FindingsThe presence of openings reduced the punching shear capacity. The small opening's location and orientation have almost no effect except for one slab. For slabs of large openings, the presence of openings reduced the punching capacity. The punching capacity is higher when the openings are farther from the column. The numerically obtained results of slabs with rectangular columns show lower punching capacity compared to slabs of squared columns with the same length of the punching shear control perimeter. The punching capacity for all slabs is predicted by ACI318–19 and Eurocode (EC2-04) and it is found that Eurocode (EC2-04) provided a closer estimation.Originality/valueThe slabs considered for calibration were reinforced with four different punching shear reinforcement configurations, namely; ordinary closed rectangular stirrups, rectangular spiral stirrups, advanced rectangular spiral stirrups and circular spiral. Generally, there has been limited research on concrete flat slabs with openings in comparison with other subjects related to structural engineering (Guan, 2009) and no research on punching shear with openings of slabs reinforced with these reinforcement schemes. The available research focussed on the effects of openings on the flexural behaviour of reinforced concrete slabs includes Casadei et al. (2003), Banu et al. (2012) and Elsayed et al. (2009). In addition, experimental tests that examined slabs supported on rectangular columns are very limited.


2019 ◽  
Author(s):  
Mohammad Mehdi Alinia ◽  
Arash Saeidpour ◽  
Mozhdeh Amani

Curved panels are widely used in different structures from fuselage of planes to curved bridge girders. An accurate understanding of buckling and postbuckling behavior of curved panels under different loadings is essential for efficient structural design. The shear buckling and postbuckling behavior of laterally pressured thin curved panels under gradually increasing in-plane shear forces is investigated. The magnitude of the lateral forces, the radius of curvature and the aspect ratio of panels are considered in the parametric studies. A classic theoretical formulation of curved panels buckling load is reexamined and compared to experimental results. The results showed that inward pressure eliminates the snap-through phenomenon and the softening stage in the response of shallow curved panels. However, the buckling characteristics are not significantly affected in the moderately curved panels under small pressures. In addition, the magnitude of inward pressures that would affect the shear buckling and postbuckling behavior of panels depends on their radius of curvature. The ultimate shear capacity of a highly curved panel is considerably reduced due to the increasing presence of inward pressures. The failure mode of highly curved panels are associated with the occurrence of unstable buckling; and as a result, the released strain energy prevents the occurrence of hardening stages.


Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6103
Author(s):  
Zheng-Nan Jing ◽  
Rong-Gui Liu ◽  
Gui-Hua Xie ◽  
Dan Liu

Deep T-section beams have been widely used in engineering structures due to their high bearing capacity, high construction efficiency and economic benefits, while the current beam design theory can hardly interpret reasonably the mechanical behaviors of deep beams. The performance features of the deep T-beam were investigated, involving in strain distribution and principal stress trace using experimental tests. Different near surface mounted (NSM) reinforcement schemes were proposed for deep T-beams aiming at improving the shear capacity. The results show that the behaviors of deep T-beams dissatisfy the assumption of plane cross-section, and the ‘strut-and-tie’ model is applicable in such structures. The reinforcement systems can significantly relieve the strain concentration, mid-span deflection and crack width in deep T-beams, consequently improving the shear capacity range from 45 to 65%. The scheme is preferential for the reinforcement of deep T-beams when the applied angles, positions and lengths of CFRP bars are optimized based on the ‘strut-and-tie’ model.


Author(s):  
Pramod Rai ◽  
Kitjapat Phuvoravan

This research investigated the shear strengthening technique of Reinforced Concrete (RC) deep beams using a V-shaped external rod system. Shear behavior, the stress in an external rod, and the shear capacity at the diagonal shear failure of a strengthened beam were focused mainly. Experimental tests of control and two strengthened beams were carried out to observe the effect of the external rod on shear behavior of RC deep beam. A theoretical approach to compute the stress in the external rod and the nominal strength of the strengthened beam in the diagonal shear failure were examined based on the experimental test results and verified using Finite Element Method (FEM) in ABAQUS. The computed nominal shear strength of the strengthened beam was 10% higher than the experimental test. The strengthening technique shifted the brittle shear failure to ductile shear failure and improved the performance of RC deep beam.


2016 ◽  
Vol 11 (1) ◽  
pp. 70-76
Author(s):  
Raitis Lacis

This paper presents results of the laboratory tests of timber-concrete structural connectors applicable (but not limited to) road/pedestrian bridges. The tested elements are discrete circular hollow section connectors installed in the pre-drilled slots of a glulam. Symmetrical push-out tests are conducted for two groups of connectors: 1) with wood core not removed; no interlayer between wood and concrete; 2) concrete in-fill core instead of the wood core; waterproofing membrane interlayer between concrete and timber elements. Main structural parameters of the connectors are established including ultimate shear capacity and slip modulus. Relationship between the connector’s stiffness and ultimate shear capacity is established and failure mechanisms are briefly discussed.


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