Confinement of Full-Scale Masonry Columns with FRCM Systems

2017 ◽  
Vol 747 ◽  
pp. 374-381 ◽  
Author(s):  
Gennaro Maddaloni ◽  
Alessio Cascardi ◽  
Alberto Balsamo ◽  
Marco di Ludovico ◽  
Francesco Micelli ◽  
...  
Keyword(s):  
Axial Strain ◽  
Experimental Tests ◽  
Full Scale ◽  
Experimental Program ◽  
Load Carrying Capacity ◽  
Compression Tests ◽  
Load Carrying ◽  
A New Technique ◽  
Real Scale ◽  
Inorganic Matrix

The effectiveness of FRP systems as a confinement technique to strengthen masonry columns has been widely investigated in the last decades. Recently, a new technique, Fabric Reinforced Cementitious Matrix (FRCM), based on the use of fibrous nets embedded in inorganic matrix, has been developed and investigated as a strengthening solution in masonry buildings. Actually, the number of experimental tests on masonry columns confined by using FRCM systems is very limited, especially for real scale specimens. To fill such gap an experimental program aimed at investigating the behaviour of full scale columns made of limestone masonry blocks confined with different FRCM systems has been carried out. The results of four uniaxial compression tests are illustrated and discussed. The used FRCM systems are made with glass and basalt dry nets embedded in a lime-based mortar. The influence of transverse confinement by using internal reinforcement in forms of pultruded GFRP bars has been also investigated. The mechanical properties of the confined specimens resulted increased in terms of load-carrying capacity and ultimate axial strain.

Experimental and Analytical Investigation of Steel Reinforced Grout (SRG) Strengthened Masonry Panels

2017 ◽  
Vol 747 ◽  
pp. 226-233
Author(s):  
Xuan Wang ◽  
Chi Chiu Lam ◽  
Vai Pan Iu ◽  
Kun Pang Kou
Keyword(s):  
Load Capacity ◽  
Experimental Tests ◽  
Analytical Investigation ◽  
Experimental Program ◽  
Load Carrying Capacity ◽  
Compression Tests ◽  
Clay Brick ◽  
Diagonal Compression ◽  
Load Carrying ◽  
Externally Bonded

This paper illustrates the results of experimental and analytical investigation carried out on masonry panels built by grey clay brick (GCB) from the Lingnan Region, China, reinforced with externally bonded Steel Reinforced Grout (SRG) system. The experimental program involves diagonal compression tests on two unreinforced and two double side reinforced panels. The main outcomes of the experimental tests include load-displacement response, stiffness, load capacity and failure mechanism. The results show that the contribution of the strengthening system to the increase of the load carrying capacity and ductility. Finally, analytical model is proposed and compared with experimental results.

Experimental and numerical investigation on ultimate strength of four-legged latticed columns

2021 ◽  
pp. 136943322110015
Author(s):  
Yinqi Li ◽  
Feng Liu ◽  
Wenming Cheng ◽  
Huasen Liu
Keyword(s):  
Ultimate Strength ◽  
Structural Engineering ◽  
Analytical Techniques ◽  
Experimental Tests ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Compressive Loads ◽  
Initial Geometric Imperfections ◽  
Combined Data ◽  
Loading Eccentricity

Latticed built-up columns are applied more extensively than solid columns in structural engineering because of their excellent load-carrying capacity and light weight. Studies on the bearing capacity of latticed columns, particularly multiple-legged latticed columns, need to be conducted in detail. In this investigation, seven four-legged latticed column specimens of different bar sections, bar distributions and loading eccentricities under compressive loads were subjected to experimental tests. The initial geometric imperfections of the legs and bars were measured and introduced into the FE numerical method. The experimental results were then compared with those of Geometrical and Material Non-Linear Analysis with Imperfection in ABAQUS software. The combined data indicate that the bar section, bar distribution and loading eccentricity significantly influenced the ultimate strength of four-legged latticed columns, producing maximum variations of 105.67%, 65.7% and 48.48%, respectively. This investigation demonstrates the influence of lacing bars and improves the results obtained from FE numerical analytical techniques.

Contact shear stresses in dowel-type joints with expansive kits of timber structures

2016 ◽  
Vol 231 (1) ◽  
pp. 140-149
Author(s):  
Jose G Fueyo ◽  
Manuel Domínguez ◽  
Jose A Cabezas
Keyword(s):  
Experimental Tests ◽  
Element Model ◽  
Shear Stresses ◽  
Load Carrying Capacity ◽  
Timber Structures ◽  
Expansion Process ◽  
Global Response ◽  
Load Carrying ◽  
Overall Performance ◽  
The Relationship

This paper studies the shear stresses appearing in the contact zones of dowel-type joints of timber structures using expansive kits. To achieve this goal, a finite element model capable of determining the effect of using these kits on the global response of the joint has been prepared. For its development, different tools have been used to model the expansion process, the contact between the different parts of the joint, the compression pressures triggered by this contact, the resulting shear stresses caused by friction and, finally, the effect of all these circumstances on the overall performance of the joint, especially on the relationship between the applied load and the related displacement. The design of the model has been checked for correctness using experimental tests. The results obtained show that the use of expansive kits slightly improves the load-carrying capacity of the dowel through the rope effect.

Full-Scale Experiments and Analyses of Cellular Hull Sections in Compression

1996 ◽  
Vol 118 (3) ◽  
pp. 232-237 ◽  
Author(s):  
R. J. Dexter ◽  
J. M. Ricles ◽  
L.-W. Lu ◽  
A. A.-K. Pang ◽  
J. E. Beach
Keyword(s):  
Yield Stress ◽  
Ultimate Load ◽  
High Strength ◽  
Load Carrying Capacity ◽  
Compression Tests ◽  
Plate Buckling ◽  
Critical Stresses ◽  
Collapse Strength ◽  
Load Carrying ◽  
Multiple Cell

Compression tests were conducted on high-strength single-cell and multiple-cell box sections with plate width-to-thickness (b/t) ratios ranging from 48 to 96. Local plate buckling occurred at stresses as low as 5 percent of the yield stress, whereas the ultimate compression stress ranged from 38 to 72 percent of the yield stress. These critical stresses were not significantly affected by the length of the specimen, the number of cells, the boundary conditions, or lateral load. Simple empirical design equations based only on b/t gave estimates of the collapse strength within five percent in all cases. Finite-element analyses were able to predict the significant reserve load-carrying capacity and ductility after ultimate load, which was dependent on the length of the specimen as well as the b/t ratio.

Compensating the flexibility uncertainties of a cable suspended robot using SMC approach

Robotica ◽  
2014 ◽  
Vol 33 (3) ◽  
pp. 578-598 ◽  
Author(s):  
M. H. Korayem ◽  
M. Taherifar ◽  
H. Tourajizadeh
Keyword(s):  
Sliding Mode ◽  
Longitudinal Vibration ◽  
Experimental Tests ◽  
Sliding Mode Controller ◽  
Parametric Uncertainties ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Varying Length ◽  
The Impact ◽  
Positive Effect

SUMMARYA sliding mode controller is designed to compensate for the flexibility uncertainties of a cable robot and improve its tracking performance. Of the most significant sources of these uncertainties are the elasticity of the cables and the flexibility of the joints. A favorable approach to improve the accuracy of the system is first to model the cable and joint flexibilities and then convert the model uncertainties into parametric uncertainties. Parametric uncertainties are the product of imprecise flexibility coefficients and are finally neutralized by a sliding mode controller. The flexibility in cables is modeled by considering the longitudinal vibration of the time-varying length cables. A simulation study is carried out to confirm the presented model and the positive effect of the designed controller. Then the impact of these uncertainties on the dynamic load carrying capacity (DLCC) of the robot is examined and compared for different cases. Finally, experimental tests are conducted on the IUST (Iran University of Science and Technology) cable-suspended robot to validate the presented theories and simulation results.

scholarly journals Response of Skirted Foundations Resting on Dry Medium Dense Sand

2018 ◽  
Vol 4 (6) ◽  
pp. 1193 ◽  
Author(s):  
Lujain Haider ◽  
Haider M. Mekkiyah
Keyword(s):  
Cross Section ◽  
Carrying Capacity ◽  
Considerable Increase ◽  
Experimental Tests ◽  
Load Carrying Capacity ◽  
Dense Sand ◽  
Load Carrying ◽  
Different Diameters ◽  
Large Soil ◽  
Settlement Behaviour

Experimental model tests were carried out to study the response of skirted foundation resting on dry sand.  The experiments were performed in a large soil container (1000  1000 mm in cross section and 800 mm in height).  Skirts with three different lengths (L) varied from 0.5D to 1.5D was attached to the edge of shallow circular foundations having three different diameters (D=60, 90 and 120 mm). Different parameters have been studied; these parameters involve skirt length, foundation size and skirt conditions. Skirts with open end and closed end were used. The relative density was kept constant and equals to 60%. The case of foundation without skirt (L=0) was initially tested and set as a reference for comparison purpose. From the results of experimental tests, it was found that the skirt modifies the load-settlement behaviour, increasing the load carrying capacity and reducing the foundation settlement. The results also indicate that load carrying capacity of skirted foundation increases with increase skirt length as well as foundation size. The results show that using skirt with closed end brought a considerable increase in load carrying capacity than that of open end.

scholarly journals Stability and Load-Carrying Capacity of Thin-Walled FRP Composite Z-Profiles under Eccentric Compression

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2956
Author(s):  
Hubert Debski ◽  
Sylwester Samborski ◽  
Patryk Rozylo ◽  
Pawel Wysmulski
Keyword(s):  
Composite Material ◽  
Carrying Capacity ◽  
Progressive Failure ◽  
Compressive Load ◽  
Experimental Tests ◽  
Numerical Results ◽  
Load Carrying Capacity ◽  
Plastic Composite ◽  
Load Carrying ◽  
Thin Walled

This study investigates the effect of eccentric compressive load on the stability, critical states and load-carrying capacity of thin-walled composite Z-profiles. Short thin-walled columns made of carbon fiber-reinforced plastic composite material fabricated by the autoclave technique are examined. In experimental tests, the thin-walled structures were compressed until a loss of their load-carrying capacity was obtained. The test parameters were measured to describe the structure’s behavior, including the phenomenon of composite material failure. The post-critical load-displacement equilibrium paths and the acoustic emission signal enabling analysis of the composite material condition during the loading process were measured. The scope of the study also included performing numerical simulations by finite element method to solve the problem of non-linear stability and to describe the phenomenon of composite material damage based on the progressive failure model. The obtained numerical results showed a good agreement with the experimental characteristics of real structures. The numerical results are compared with the experimental findings to validate the developed numerical model.

Influence of the assumed effective length factor on the load carrying capacity of steel angles in compression

1995 ◽  
Vol 22 (6) ◽  
pp. 1171-1177
Author(s):  
Murray C. Temple ◽  
Davide M. Petretta ◽  
Catherine Morand
Keyword(s):  
Principal Axis ◽  
Design Procedure ◽  
Effective Length ◽  
Experimental Program ◽  
Load Carrying Capacity ◽  
Effective Length Factor ◽  
Compression Members ◽  
Load Carrying ◽  
Steel Angles ◽  
Compressive Resistance

Single angle compression members are usually attached by one leg only. In Canada it is common practice when designing such members to neglect the end eccentricities, to assume the angle buckles about the minor principal axis, and to assume an effective length factor of 1.0. Clause 13.3.1 of S16.1 is then used to calculate the compressive resistance. An experimental program was undertaken to determine the effect that the assumed effective length factor has on the compressive resistance of such angles. Eighteen specimens were tested in which the angles were slender or of intermediate length. The effective length factor was assumed to be 1.0, 0.9, or 0.5. It was determined that when there is substantial restraint at the ends of the angles the assumed effective length factor has a very significant effect on the compressive resistance of an angle attached by one leg. Key words: angles, axis of bending, buckling, design procedure, effective length factor.

Limit Load Analysis of Cylindrical Vessels Under Internal Pressure and Axial Strain

2011 ◽  
Author(s):  
Xian-Kui Zhu
Keyword(s):  
Internal Pressure ◽  
Carrying Capacity ◽  
Pressure Vessel ◽  
Axial Strain ◽  
Limit State ◽  
Limit Load ◽  
Operating Pressure ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Load Analysis

Strain-based design is a newer technology used in safety design and integrity management of oil and gas pipelines. In a traditional stress-based design, the axial stress is relatively small compared to the hoop stress generated by internal pressure in a line pipe, and the limit state in the pipeline is usually load-controlled. In a strain-based design, however, axial strain can be large and the load-carrying capacity of pipelines could be reduced significantly below an allowed operating pressure, where the limit state is controlled by an axial strain. In this case, the limit load analysis is of great importance. The present paper confirms that the stress, strain and load-carrying capacity of a thin-walled cylindrical pressure vessel with an axial force are equivalent those of a long pressurized pipeline with an axial tensile strain. Elastic stresses and strains in a pressure vessel are then investigated, and the limit stress, limit strain and limit pressure are obtained in terms of the classical Tresca criterion, von Mises criteria, and a newly proposed average shear stress yield criterion. The results of limit load solutions are analyzed and validated using typical experimental data at plastic yield.

Experimental Tests on Strengthened Masonry Vaults

2014 ◽  
Vol 578-579 ◽  
pp. 1396-1399 ◽  
Author(s):  
Łukasz Hojdys ◽  
Piotr Krajewski
Keyword(s):  
Carbon Fiber ◽  
Glass Fiber ◽  
Failure Modes ◽  
Cement Mortar ◽  
Experimental Tests ◽  
Load Carrying Capacity ◽  
Lime Mortar ◽  
Clay Bricks ◽  
Load Carrying ◽  
Masonry Vaults

This paper reports and discusses the results of experiments performed on masonry barrel vaults strengthened externally with a composite material. The vaults characterized by 125-mm thickness, 2000-mm internal span and 730-mm rise, were built of solid clay bricks and lime mortar. As a strengthening glass fiber grids or carbon fiber grids were used. They were embedded in a polymer-cement mortar at the vaults extrados. The main aim of presented research was to determine load-carrying capacity and examine failure modes of tested specimens. The results of performed tests show that observed failure modes depended on reinforcement ratio of strengthening layer. The specimen strengthened with one layer of glass fiber grid failed due to fibers rupture, whereas the vault strengthened with carbon fiber grid failed due to sliding along a mortar joint just above the abutment.

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