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.

Laboratory Tests on Masonry Vaults with Backfill Strengthened at the Extrados

2014 ◽  
Vol 624 ◽  
pp. 510-517 ◽  
Author(s):  
Łukasz Hojdys ◽  
Piotr Krajewski
Keyword(s):  
Carrying Capacity ◽  
Laboratory Tests ◽  
Failure Modes ◽  
Lightweight Concrete ◽  
Load Carrying Capacity ◽  
Lime Mortar ◽  
Clay Bricks ◽  
Load Carrying ◽  
Masonry Vaults ◽  
Strengthening Method

This paper deals with the experimental behavior of two masonry vaults strengthened externally with a composite material. Thickness, internal span and rise of the vaults were 120 mm, 2000 mm and 730 mm, respectively. Masonry was made of solid clay bricks and lime mortar. An alkali-resistant coated glass fiber grid embedded in a cement-based matrix was used as strengthening material. The tensile strength of the glass grid as specified by its manufacturers was about 45kN/m. Both of the tested vaults were strengthened at their extrados. Expanded clay aggregate or lightweight concrete were used as a backfill. The vaults were tested under monotonic vertical loads applied at a quarter span. The main aim of the research presented here was to develop a strengthening method acceptable for vaults with frescoes, to determine the load-carrying capacity and to examine failure modes of the tested specimens. The results of the tests show that observed failure modes depend on the backfill configuration.

Experimental Behavior of Masonry Vaults Strengthened with Thin Extradoxal or Intradoxal Layer of Fiber Reinforced Lime Mortar

2017 ◽  
Vol 747 ◽  
pp. 274-281 ◽  
Author(s):  
Natalino Gattesco ◽  
Ingrid Boem ◽  
Alessandra Gubana ◽  
Davide Menegon ◽  
Norman Bello ◽  
...  
Keyword(s):  
Thin Layer ◽  
Experimental Tests ◽  
Horizontal Load ◽  
Actual Behavior ◽  
Cyclic Tests ◽  
Lime Mortar ◽  
Numerical Investigations ◽  
The Third ◽  
Loading Patterns ◽  
Masonry Vaults

The results of a first experimental research program on masonry vaults strengthened by means of GFRP meshes embedded in a thin layer of lime mortar, are herein presented. The tests were designed to reproduce the pattern of a transversal horizontal load proportional to the vault self-weight. The typical simplified loading patterns generally used for the experimental tests concern concentrated vertical loads at the crown section or at 1/4 of the span, but some numerical investigations evidenced that these configurations are not able to reproduce the actual behavior and the effectiveness of the reinforcement. So a specific rig was designed to apply the horizontal load pattern.Solid brick masonry barrel vaults were considered (thickness 120 mm, arch span 4000 mm, arch rise/radius = 0.75). Three quasi-static cyclic tests were performed: the first concerned an unreinforced vault, the second a vault reinforced at the extrados through the application of a mortar coating reinforced with a GFRP mesh and the third reinforced at the intrados surface with the same technique. The experimental results demonstrated the technique effectiveness and the important increment of ductility of the vaults.

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.

Numerical and experimental evaluation of mechanical performance of the multifunctional energy storage composites

2021 ◽  
pp. 002199832110495
Author(s):  
Yinan Wang ◽  
Fu-Kuo Chang
Keyword(s):  
Energy Storage ◽  
Carbon Fiber ◽  
Composite Laminates ◽  
Failure Modes ◽  
Mechanical Performance ◽  
Fiber Composite ◽  
Mechanical Damage ◽  
Experimental Tests ◽  
Structural Element ◽  
Carbon Fiber Composite

This work presents numerical simulation methods to model the mechanical behavior of the multifunctional energy storage composites (MESCs), which consist of a stack of multiple thin battery layers reinforced with through-the-hole polymer rivets and embedded inside carbon fiber composite laminates. MESC has been demonstrated through earlier experiments on its exceptional behavior as a structural element as well as a battery. However, the inherent complex infrastructure of the MESC design has created significant challenges in simulation and modeling. A novel homogenization technique was adopted to characterize the multi-layer properties of battery material using physics-based constitutive equations combined with nonlinear deformation theories to handle the interface between the battery layers. Second, mechanical damage and failure modes among battery materials, polymer reinforcements, and carbon fiber-polymer interfaces were characterized through appropriate models and experiments. The model of MESCs has been implemented in a commercial finite element code in ABAQUS. A comparison of structural response and failure modes from numerical simulations and experimental tests are presented. The results of the study showed that the predictions of elastic and damage responses of MESCs at various loading conditions agreed well with the experimental data. © 2021

scholarly journals Experimental Research on AFRP Reinforced Recycled Steel Tube Columns Subjected to Axial Compression

2017 ◽  
Vol 26 (6) ◽  
pp. 096369351702600
Author(s):  
Min Hou ◽  
Jiangfeng Dong ◽  
Lang Li ◽  
Shucheng Yuan ◽  
Qingyuan Wang
Keyword(s):  
Carrying Capacity ◽  
Failure Modes ◽  
Basalt Fiber ◽  
Steel Tube ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
The One ◽  
Effective Use

In order to make an effective use of the recycled aggregate concrete (RAC), a total of six steel tube RAC columns and six basalt fiber (BF) reinforced RAC columns, including six columns that were externally strengthened with aramid fiber reinforced polymer (AFRP) sheets, were fabricated and tested. This were to provide a strengthening solution to upgrade the load carrying capacity, ductility and rigidity of the RAC filled steel tube columns. Besides, the recycled coarse aggregate (RCA) replacement ratios for production of RAC was analyzed. The results show that the load carrying capacity and ultimate displacements of the RAC filled ST columns could be improved greatly by adding of basalt fiber, especially for the specimens with 50% and 100% RCA replacement ratio. The similar result was also found for the specimens strengthened with AFRP reinforcement, along with the stiffness of the columns were enhanced obviously. Moreover, the highest improving on the load carrying capacity, stiffness and ultimate displacement was found in the specimens both reinforced by adding of BF and strengthening of AFRP. However, the failure modes of the specimens with BF reinforced RAC gave a higher deformability than the one with AFRP strengthening arrangement.

Prediction model and parametric study on CFRP flat-joggle-flat hybrid (bonded/bolted) joints

2020 ◽  
Vol 54 (26) ◽  
pp. 4025-4034
Author(s):  
Chang Xu ◽  
Wenjing Wang ◽  
Zhiming Liu ◽  
Chen Fu
Keyword(s):  
Prediction Model ◽  
Carrying Capacity ◽  
Failure Modes ◽  
Diameter Ratio ◽  
Load Carrying Capacity ◽  
Bolted Joint ◽  
Hybrid Joint ◽  
Load Carrying ◽  
Bonded Joint ◽  
Adhesively Bonded Joint

As the weakness zone of composite structures, joints are of great concern. Adding fasteners in the bonded joint is another type of jointing, technology used in engineering. In this research, considering a new type of flat-joggle-flat carbon fibre reinforced plastic (CFRP) joint, a prediction model based on the commercial software ABAQUS was proposed to predict the joint load carrying capacity and analyse the joint failure modes. Tensile tests were performed to verify the validity of the model. Furthermore, the orthogonal design was applied to explore the effects of four kinds of factors on the hybrid joints. The results showed that the load-carrying capacity of the hybrid joint improved by 40.5% and 31.9% on average, compared with that of the adhesively bonded joint and the bolted joint, respectively. The carrying capacity for the bonded joint, bolted joint and hybrid joint predicted by the model has error values of 3.5%, 2.7% and 3.1%, respectively, which illustrates good accuracy with the test results. The width-to-diameter ratio appears to have the most substantial effect on the first drop load and the maximum load of the hybrid joint. The failure modes are influenced by the width-to-diameter ratio, edge-to-diameter ratio and stacking sequence.

STUDY ON FATIGUE BEHAVIOR OF STRENGTHENED NON-LOAD-CARRYING CRUCIFORM WELDED JOINTS USING CARBON FIBER SHEETS

2012 ◽  
Vol 12 (01) ◽  
pp. 179-194 ◽  
Author(s):  
TAO CHEN ◽  
QIAN-QIAN YU ◽  
XIANG-LIN GU ◽  
XIAO-LING ZHAO
Keyword(s):  
Stress Concentration ◽  
Carbon Fiber ◽  
Welded Joints ◽  
Failure Modes ◽  
Fatigue Behavior ◽  
Local Stress ◽  
Fatigue Loading ◽  
Cfrp Sheets ◽  
Load Carrying ◽  
Weld Toe

This paper reports an experimental study on the use of carbon fiber-reinforced polymer (CFRP) sheets to strengthen non-load-carrying cruciform welded joints subjected to fatigue loading. Failure modes and corresponding fatigue lives were recorded during tests. Scatter of test results was observed. Thereafter, a series of numerical analyses were performed to study the effects of weld toe radius, the number of CFRP layers and Young's modulus of reinforced materials on local stress concentration at a weld toe. It was found that fatigue life of such welded connections can be enhanced because of the reduction of stress concentration caused by CFRP strengthening. Parametric study indicates that the weld toe radius and the amount of CFRP are the key parameters influencing the stress concentration factors and stress ranges of the joint. Enhancement of modulus for adhesive and CFRP sheets can also be beneficial to the fatigue performance to some extent.

Investigation on the Post-Ultimate Strength Behaviour of Sandwich Plate

2014 ◽  
Author(s):  
Wei Wang ◽  
Weijun Xu ◽  
Xiongliang Yao ◽  
Nana Yang
Keyword(s):  
Ultimate Strength ◽  
Carrying Capacity ◽  
Failure Modes ◽  
Sandwich Plate ◽  
Experimental Results ◽  
Sandwich Plates ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Strength Behavior ◽  
Simulation Results

This paper focuses on the post-ultimate strength behavior of sandwich plates. With widely application of the laminate on the ship and offshore structures, the post-ultimate strength behavior is becoming more important for safety evaluation of structures. Since the post-ultimate strength behavior can reflect the collapse extent of sandwich plate when subjected to extreme loads. A sandwich plate was modeled by FEM, its load-displacement relationship was obtained and its collapse characteristics were analyzed. The load-displacement relationship indicates its post-ultimate strength behavior, which is shown as that the load carrying capacity has a rapidly reduction when the ultimate strength is exceeded, and that the failure modes of the sandwich plate are determined by the parameter of individual layer. The simulation results were validated against experimental results. Conclusions are drawn: the displacement of sandwich plate under axial compression increased slowly before reaching the ultimate strength, once the ultimate strength was exceeded, the loads exerted on the structures sharply decreased with slowly increased displacement until the plate cracked. The simulation results have a good agreement with the experimental results. The mainly failure modes of sandwich plates can be interpreted as delamination between skin & core and core compression fracture, which are typical failure modes in engineering. The stiffness of sandwich structures decreased due to the interlaminar cracking or skin fracture, further the load carrying capacity decreased, which is of significance for guiding the design of sandwich structures.

Reliability analysis of wood I-joists

1993 ◽  
Vol 20 (4) ◽  
pp. 564-573 ◽  
Author(s):  
R. O. Foschi ◽  
F. Z. Yao
Keyword(s):  
Reliability Analysis ◽  
Carrying Capacity ◽  
Failure Modes ◽  
Limit State ◽  
Load Carrying Capacity ◽  
Limit States ◽  
Element Analysis ◽  
Strength Limit ◽  
Reliability Method ◽  
Load Carrying

This paper presents a reliability analysis of wood I-joists for both strength and serviceability limit states. Results are obtained from a finite element analysis coupled with a first-order reliability method. For the strength limit state of load-carrying capacity, multiple failure modes are considered, each involving the interaction of several random variables. Good agreement is achieved between the test results and the theoretical prediction of variability in load-carrying capacity. Finally, a procedure is given to obtain load-sharing adjustment factors applicable to repetitive member systems such as floors and flat roofs. Key words: reliability, limit state design, wood composites, I-joist, structural analysis.

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