Experimental Testing of Slender Load-Bearing Masonry Walls with Realistic Support Conditions

2021 ◽  
Author(s):  
Clayton Edward James Pettit ◽  
Erum Mohsin ◽  
Carlos Cruz-Noguez ◽  
Alaa E Elwi
Keyword(s):  
Flexural Rigidity ◽  
Experimental Testing ◽  
Design Parameters ◽  
Masonry Walls ◽  
Bending Moments ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Moment Distribution ◽  
Support Conditions ◽  
The Moment

Slender, load-bearing masonry walls with slenderness ratios (h/t) greater than 30 are required to be designed as pinned-pinned elements as per North American provisions for masonry, CSA S304-14 (2019) and TMS 402-16 (2016). This provision neglects the contribution of the reactive stiffness of the foundation to the strength of the wall and its effect on the redistribution of bending moments along its height. Eight full-scale masonry walls built with different degrees of base stiffness and tested under an eccentric axial load. Results from the tests showed an increased load-bearing capacity and decreased deflections with increased rotational base stiffness. Experimental data was used to determine key design parameters including the effective flexural rigidity and the moment distribution along the height of the walls. Comparing values of effective flexural rigidity determined from experimental results to code provisions, it was found both codes tend to underestimate the effective flexural rigidity of the walls.

Analytical modeling of masonry load-bearing walls

2003 ◽  
Vol 30 (5) ◽  
pp. 795-806 ◽  
Author(s):  
Yi Liu ◽  
J L Dawe
Keyword(s):  
Flexural Rigidity ◽  
Computer Application ◽  
Masonry Walls ◽  
Load Bearing ◽  
Analytical Technique ◽  
Reinforced Masonry ◽  
Material Stiffness ◽  
The Moment ◽  
Magnification Effect

An analytical technique was developed and encoded for computer application to study the behaviour of concrete masonry load-bearing walls under various loading conditions. Both geometrical and material nonlinearities to account for the moment magnification effect and the degradation of material stiffness are included in the development. Effects of vertical reinforcing steel, masonry tensile cracking, and compressive crushing are included directly in the moment–curvature relationship, which is used in the determination of element stiffnesses at successive load increments. A parametric study was conducted following verification of the analytical model by comparing results with experimental test data. Effective flexural rigidity (EIeff) values at failure were obtained analytically and compared with values suggested in the Canadian masonry code CSA-S304.1-M94. It was concluded that CSA-S304.1-M94 tends to underestimate EIeff values for reinforced walls and thus leads to a conservative design over a range of parameters. Based on approximately 500 computer model tests, a lower bound bilinear limit for the effective rigidity of reinforced masonry walls was established. This limit is believed to provide an accurate and realistic estimate of EIeff.Key words: walls, load bearing, masonry, analytical, nonlinear, rigidity, stress–strain, moment–curvature.

Nonlinear structural analysis of a masonry wall

2021 ◽  
Author(s):  
Guangli Du ◽  
Thomas Cornelius ◽  
Joergen Nielsen ◽  
Lars Zenke Hansen
Keyword(s):  
Bearing Capacity ◽  
Material Properties ◽  
Slenderness Ratio ◽  
Masonry Wall ◽  
Masonry Walls ◽  
Vertical Load ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Support Conditions ◽  
Theoretical Developments

<p>Structural modelling of a masonry wall is challenging due to material properties, eccentricity of the vertical load, slenderness ratio etc. In recent theoretical developments for design of masonry walls, a new “Phi” method to determine the eccentricity is adopted in Eurocode 6. However, the comparisons between this method and the conventional “Ritter” method shows that for certain prerequisites it would result in substantial different load-bearing capacity. Hence, in order to investigate how support conditions influence the load bearing capacity of the wall, this study performs a nonlinear numerical analysis of a wall for several load cases in ABAQUS and the result is verified with an independently developed calculation tool using MATLAB. The results show that the top rotation plays a significant role for the load bearing capacity of the masonry wall supported by slabs at both ends. It is difficult to estimate the eccentricities without a rigorous calculation.</p>

scholarly journals Bending Stiffness, Load-Bearing Capacity and Flexural Rigidity of Slender Hybrid Wood-Based Beams

Forests ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 703 ◽  
Author(s):  
Barbara Šubic ◽  
Gorazd Fajdiga ◽  
Jože Lopatič
Keyword(s):  
Bearing Capacity ◽  
Flexural Rigidity ◽  
Bending Stiffness ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Reinforced Polymer ◽  
Glass Fibre Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Hybrid Beams ◽  
Fibre Reinforced Polymer

Modern architecture suggests the use of opened spaces with large transparent envelope surfaces. Therefore, windows of long widths and large heights are needed. In order to withstand the wind loads, such wooden windows can be reinforced with stiffer materials, such as aluminium (Al), glass-fibre reinforced polymer (GFRP), and carbon-fibre reinforced polymer (CFRP). The bending stiffness, load-bearing capacity, and flexural rigidity of hybrid beams, reinforced with aluminium, were compared through experimental analysis, using a four-point bending tests method, with those of reference wooden beams. The largest increases in bending stiffness (29%–39%), load-bearing capacity (33%–45%), and flexural rigidity (43%–50%) were observed in the case of the hybrid beams, with the highest percentage of reinforcements (12.9%—six reinforcements in their tensile and six reinforcements in their compressive zone). The results of the experiments confirmed the high potential of using hybrid beams to produce large wooden windows, for different wind zones, worldwide.

Composite action in masonry walls under vertical in-plane loading: experimental results compared with predictions

2015 ◽  
Vol 42 (7) ◽  
pp. 449-462
Author(s):  
A.T. Vermeltfoort ◽  
D.R.W. Martens
Keyword(s):  
Bearing Capacity ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Compressive Force ◽  
Reinforced Concrete Beams ◽  
Elastic Behavior ◽  
Masonry Walls ◽  
Load Bearing Capacity ◽  
Cracking Behavior ◽  
Load Bearing

The results of five experimental test series on masonry walls supported by reinforced concrete beams or slabs are reported and compared to theoretical predictions of the load bearing capacity. The experiments were performed on deep masonry beams built with respectively calcium silicate and clay brick. Investigated parameters were: position of the supports, concrete beam-masonry interface, concrete beam stiffness, type of loading, and height of masonry wall and concrete beam. Based on literature, the method proposed by Davies and Ahmed as well as the method according to Eurocode 6 were used to estimate the load bearing capacity of the tested masonry walls supported by concrete beams. The method of Davies and Ahmed allows for the determination of the stresses and stress resultants in the masonry. The analysis shows that near the support an inclined compressive force acts at the bed joint, which means that a shear-compression stress state exists in the bed joint. Strength evaluation has been carried out using the Mann-Müller criterion that is adopted in Eurocode 6. Based on the test results, it may be concluded that both methods yield conservative values of the load bearing capacity, as could be expected. Before cracking a linear elastic behavior was observed, while after cracking a strut-and-tie model may be applied. To develop more accurate design models, it is recommended to investigate the post-cracking behavior in more detail.

Study on failure mechanism and end construction influences of double rectangular tube assembled buckling-restrained brace

2016 ◽  
Vol 20 (10) ◽  
pp. 1572-1585 ◽  
Author(s):  
Zi-qin Jiang ◽  
Yan-lin Guo ◽  
Ai-Lin Zhang ◽  
Chao Dou ◽  
Cai-Xia Zhang
Keyword(s):  
Bearing Capacity ◽  
Rational Design ◽  
Failure Modes ◽  
High Strength ◽  
Design Parameters ◽  
Local Pressure ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Buckling Restrained Brace ◽  
Rectangular Tube

The double rectangular tube assembled buckling-restrained brace is a new type of buckling energy consumption buckling-restrained brace. Because of its external restraining members, which are bound by high-strength bolts, its mechanical mechanism is more complicated and its failure modes are more varied. In this study, the double rectangular tube assembled buckling-restrained brace composition and three types of end constructions are introduced in detail. The influences of different design parameters on the performance of double rectangular tube assembled buckling-restrained brace are studied by numerical analysis methods; the possible failure modes and the influence of the end strengthening construction of double rectangular tube assembled buckling-restrained brace are also investigated, and a number of suggestions are proposed to improve this design. This study shows that the pinned double rectangular tube assembled buckling-restrained brace has four types of typical failure modes, namely, overall buckling failure, external end local pressure-bearing failure, bending failure of the extended strengthened core region and bolt threading failure. Rational design can prevent a buckling-restrained brace from losing its load-bearing capacity. In addition, compared with the end strengthening scheme with an external hoop, the end strengthening scheme with a strengthened bench can improve the load-bearing capacity of the double rectangular tube assembled buckling-restrained brace more effectively, and a reasonable design can also save materials.

Experimental Study on Residual Load Bearing Capacity of SRC Eccentric Columns after Exposure to Fire

2010 ◽  
Vol 163-167 ◽  
pp. 2240-2246 ◽  
Author(s):  
Jun Hua Li ◽  
Yue Feng Tang ◽  
Ming Zhe Liu
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Ultimate Strength ◽  
Room Temperature ◽  
Ultimate Load ◽  
Flexural Rigidity ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Steel Reinforced Concrete

This paper provided three test data pertaining to the mechanical properties of steel reinforced concrete (SRC) eccentric columns after exposure to fire and one comparative test data pertaining to the mechanical properties of steel reinforced concrete columns at room temperature. The influence of eccentricity on failure mode, distortion performance and ultimate load bearing capacity are mainly studied. Test results show that the failure modes of steel reinforced concrete eccentric columns after exposure to fire are similar to that at room temperature. Strain along the section height at mid-span section of eccentric columns before loaded to 90% ultimate load bearing capacity is linearly distributed and well agree with the plane section supposition. After exposure to fire, the flexural rigidity and load bearing capacity of specimens are all declined compared with that at normal temperature. In various loading stages from the initial loading to 80% ultimate strength, the ratio of flexural rigidity of SRC eccentric columns after exposure to fire and at normal temperature is ranged from 0.30 to 0.59. With the same concrete strength and heating condition, the ultimate strength of specimens decreases with the increasing of eccentricity. The ultimate bearing capacity of all specimens at normal room temperature is calculated on the method proposed by Chinese regulation JGJ 138-2001. The compared results of experimental values and calculating values show that the residual load bearing capacity of SRC eccentric columns after exposure to fire is about 69% to 81% of that at room temperature.

Load Bearing Capacity of Oil Film Bearing Research

2010 ◽  
Vol 42 ◽  
pp. 255-258
Author(s):  
Hong Chao Fan ◽  
Jing Lin Tong ◽  
Xin Hua Yi ◽  
Jin Bao He ◽  
Jian Xi Yang
Keyword(s):  
Bearing Capacity ◽  
Design Method ◽  
Structural Characteristics ◽  
Load Capacity ◽  
Parameters Optimization ◽  
Design Parameters ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Oil Film ◽  
Application Requirements

The oil film have many excellences such as bigger load bearing capacity, longer life, wider velocity range, lower friction etc. The traditional design method is experience test. Even the design parameters could meet the application requirements, but they can not exert the best performance of the oil film bearing. The relationship between load bearing capacity and materials, lubricants, design parameters and structural characteristics of oil film bearing was analysed. To improve the load capacity and run at the optimal state, the objective function was built to optimize the main parameters. Optimization results showed that the load bearing capacity has been greatly improved.

Improvement of load-bearing capacity of arched support using rolled steel reinforcement in mines

2021 ◽  
pp. 58-62
Author(s):  
M. A. Baikenzhin ◽  
Zh. M. Asanova
Keyword(s):  
Bearing Capacity ◽  
Bending Moments ◽  
Rolled Steel ◽  
Load Bearing Capacity ◽  
Specific Content ◽  
Significant Saving ◽  
Load Bearing ◽  
Operation Conditions ◽  
Mine Support ◽  
Loadbearing Capacity

The economic efficiency of coal mining at the reduced cost is directly related with maintenance of operation conditions in temporary roadways. This article proposes a method of increasing the loadbearing capacity of the three-link arched support made of a special rolled profile (SRP) by increasing the stiffness moments of arched support sections subjected to the greatest bending moments. It is determined to be necessary to install the same size SPR in the support sections exposed to the greatest bending moments. Mathematical modeling of the reinforcement shows that the sufficient length of SRP segments is 30 cm. The calculations show that SRP 27 is replaceable by SRP 17 with the same size inserts, which allows saving of 10 kg of steel per each meter of the arched support. The proposed method of increasing the load-bearing capacity of the support will reduce the specific content of steel in the mine support manufacture and, thereby, will enable significant saving of material and labor resources. The studies conducted to substantiate the proposed solution include: determination of bending moments and normal forces in the three-link steel arched support by the computer-aided procedure of VNIMI (All Union Research Institute of Mining Geomechanics and Mine Surveying) for the specific existing conditions, with the subsequent choice of the required size of the support; stress–strain analysis of rock mass and mine support in ANSYS environment; economic calculation of the proposed solution effectiveness. The implemented researches give grounds to believe that the proposed variant of increasing the loadbearing capacity of the support made of the rolled steel profile can significantly improve stability of mine roadways. It is possible to strengthen the support without reducing the metal content in cases of expected deformation of the support under the influence of the confining pressure, when the other methods of maintenance-free support in roadways are ineffective or require a lot of time, materials and labor.

EXPERIMENTAL STUDY ON BUCKLING RESISTANCE TECHNIQUE OF STEEL MEMBERS STRENGTHENED USING FRP

2012 ◽  
Vol 12 (01) ◽  
pp. 153-178 ◽  
Author(s):  
PENG FENG ◽  
SAWULET BEKEY ◽  
YAN-HUA ZHANG ◽  
LIE-PING YE ◽  
YU BAI
Keyword(s):  
Bearing Capacity ◽  
Slenderness Ratio ◽  
Compressive Loading ◽  
Maximum Load ◽  
Design Parameters ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Steel Members ◽  
Buckling Resistance ◽  
Frp Strengthening

Fiber-reinforced polymer (FRP) strengthening technique to improve buckling resistance of steel members is presented in concept and experimental demonstration. The conceptual design of this method is introduced through the preliminary experiments on three specimens. Then, another 14 specimens are tested under axially compressive loading, by which the compressive behavior and the strengthening effects are investigated considering different design parameters and configuration, including the slenderness ratio, the confinement detail, the filled materials and the end connection. The strengthening effects are analyzed by the comparison of both theoretical and test results, which show that the overall buckling failure of steel members can be prevented by FRP strengthening and the ultimate loading capacity and deformation capacity of steel members are enhanced considerably. The maximum load-bearing capacity of strengthened members is 2.86 times of the nonstrengthened ones, and the failure maintains a ductile behavior. In addition, the load-bearing capacity of the members strengthened in this way is compared with the Euler loads of the original steel member and the composite member.

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