scholarly journals Mechanical Behavior of Circular Steel Tubular Beam-Columns Corroded Uniformly in Atmospheric Environment

2020 ◽  
Vol 10 (6) ◽  
pp. 1998
Author(s):  
Zhaoqi Wu ◽  
Yuan Wei ◽  
Xintao Wang ◽  
Chao Huang ◽  
Shao-Fei Jiang
Keyword(s):  
Mechanical Behavior ◽  
Carrying Capacity ◽  
Failure Modes ◽  
Safety Margin ◽  
Atmospheric Environment ◽  
Uniform Corrosion ◽  
Load Carrying Capacity ◽  
Material Degradation ◽  
Circular Steel Tube ◽  
Load Carrying

Circular steel tube members with the absence of anticorrosive protection or coating failure are prone to uniform corrosion, which threatens the reliability and safety of members in the atmospheric environment. To fully study the mechanical behavior of uniformly corroded circular steel tubes, compression test and theoretical analysis were conducted, and two methods considering section reduction and material degradation, respectively, were adopted for the calculation of ultimate load carrying capacities of specimens. The results indicate that uniform corrosion did not change the failure modes of specimens, and all of them belonged to global buckling failure. The load carrying capacities and stiffness of specimens decreased with the increase of corrosion ratio, and the degree of reduction was greater than that of material degradation, showing a linear relationship with the corrosion rate. Under the same corrosion ratio, the specimens with larger eccentricity represented more obvious load carrying capacity and stiffness degradation. The load carrying capacities predicted by both methods were in good agreement with the test results and had a certain safety margin. The conservative degree of calculation results from three specifications followed a descending order of ANSI/AISC 360-16, GB 50017-2017, and EN 1993-1-1. Under the same corrosion ratio, the load carrying capacity variation of specimens between one-sided corrosion and two-sided corrosion was less than 3%.

Investigation of Burst Pressure in T-Joints With Wall-Thinning by Using FEA

2017 ◽  
Author(s):  
Atsushi Yamaguchi
Keyword(s):  
Carrying Capacity ◽  
Safety Margin ◽  
Pressure Vessels ◽  
Burst Pressure ◽  
Load Carrying Capacity ◽  
Working Pressure ◽  
Element Analysis ◽  
T Joints ◽  
Wall Thinning ◽  
Load Carrying

Boilers and pressure vessels are heavily used in numerous industrial plants, and damaged equipment in the plants is often detected by visual inspection or non-destructive inspection techniques. The most common type of damage is wall thinning due to corrosion under insulation (CUI) or flow-accelerated corrosion (FAC), or both. Any damaged equipment must be repaired or replaced as necessary as soon as possible after damage has been detected. Moreover, optimization of the time required to replace damaged equipment by evaluating the load carrying capacity of boilers and pressure vessels with wall thinning is expected by engineers in the chemical industrial field. In the present study, finite element analysis (FEA) is used to evaluate the load carrying capacity in T-joints with wall thinning. Burst pressure is a measure of the load carrying capacity in T-joints with wall thinning. The T-joints subjected to burst testing are carbon steel tubes for pressure service STPG370 (JIS G3454). The burst pressure is investigated by comparing the results of burst testing with the results of FEA. Moreover, the maximum allowable working pressure (MAWP) of T-joints with wall thinning is calculated, and the safety margin for the burst pressure is investigated. The burst pressure in T-joints with wall thinning can be estimated the safety side using FEA regardless of whether the model is a shell model or a solid model. The MAWP is 2.6 MPa and has a safety margin 7.5 for burst pressure. Moreover, the MAWP is assessed the as a safety side, although the evaluation is too conservative for the burst pressure.

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.

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.

Experimental Investigation on Steel-Plate-Masonry Composite Column Compressive Behavior

2011 ◽  
Vol 255-260 ◽  
pp. 591-595 ◽  
Author(s):  
Deng Hu Jing ◽  
Shuang Yin Cao ◽  
Hai Tao Zhou
Keyword(s):  
Carrying Capacity ◽  
Failure Modes ◽  
Steel Plate ◽  
Local Buckling ◽  
Epoxy Adhesive ◽  
Critical Cross Section ◽  
Load Carrying Capacity ◽  
Large Space ◽  
Composite Column ◽  
Load Carrying

The steel-plate-masonry composite structure is an innovative type of structural scheme popular in masonry structures with load-bearing walls removed for a large space. A total of 4 column specimens under static loading were tested to mainly study the failure modes, load-carrying capacity, and strain distribution in the critical cross-section. Results show that the composite columns started an initial failure from local buckling of the steel plate located between binding bolts; the main factors influencing load-carrying capacity included thickness of the steel plate, type of injected material, and initial column eccentricity; the working performance of the composite column with epoxy adhesive was better than that with cement grout; and re-distribution of compressive stress existed in the steel plates of the column. Also, the ratio of service load-carrying capacity to ultimate capacity of the steel-plate-masonry composite column is about 70%.

scholarly journals Shape optimization in exoskeletons and endoskeletons: a biomechanics analysis

2012 ◽  
Vol 9 (77) ◽  
pp. 3480-3489 ◽  
Author(s):  
David Taylor ◽  
Jan-Henning Dirks
Keyword(s):  
Carrying Capacity ◽  
Failure Modes ◽  
Evolutionary Development ◽  
Load Carrying Capacity ◽  
Longitudinal Splitting ◽  
Loading Mode ◽  
Load Carrying ◽  
Sophisticated Model ◽  
Using Data

This paper addresses the question of strength and mechanical failure in exoskeletons and endoskeletons. We developed a new, more sophisticated model to predict failure in bones and other limb segments, modelled as hollow tubes of radius r and thickness t . Five failure modes were considered: transverse fracture; buckling (of three different kinds) and longitudinal splitting. We also considered interactions between failure modes. We tested the hypothesis that evolutionary adaptation tends towards an optimum value of r/t , this being the value which gives the highest strength (i.e. load-carrying capacity) for a given weight. We analysed two examples of arthropod exoskeletons: the crab merus and the locust tibia, using data from the literature and estimating the stresses during typical activities. In both cases, the optimum r/t value for bending was found to be different from that for axial compression. We found that the crab merus experiences similar levels of bending and compression in vivo and that its r/t value represents an ideal compromise to resist these two types of loading. The locust tibia, however, is loaded almost exclusively in bending and was found to be optimized for this loading mode. Vertebrate long bones were found to be far from optimal, having much lower r/t values than predicted, and in this respect our conclusions differ from those of previous workers. We conclude that our theoretical model, though it has some limitations, is useful for investigating evolutionary development of skeletal form in exoskeletons and endoskeletons.

scholarly journals Parallel Glueline of Withdrawal Capacity for Mengkulang Glulam

2021 ◽  
Vol 6 (SI4) ◽  
pp. 223-231
Author(s):  
Rohana Hassan ◽  
Nor Jihan Abd Malek ◽  
Mohd Nizam Shakimon ◽  
Mohd Sapuan Salit
Keyword(s):  
Carrying Capacity ◽  
Failure Modes ◽  
Publishing House ◽  
Glue Line ◽  
Load Carrying Capacity ◽  
Yield Model ◽  
Load Carrying ◽  
International Publishing ◽  
The Difference ◽  
Bolt Diameter

The failure modes and load-carrying capacity of timber connection can be predicted using European Yield Model (EYM). In the load-carrying capacity formula, an unknown parameter for Mengkulang Glulam with the bolt as a fastener, is the withdrawal capacity, Fax,Rk (kN). In this research, the withdrawal capacity tests were conducted with respect to the difference in bolt diameter and glue line existences. The results showed the larger diameter 18 mm parallel with the glue line giving the highest withdrawal capacity and resistance when compared to the same diameter without glue line and 14 mm diameter with and without the glue line. Keywords: Engineered Wood Product (EWP); Structural Material; Withdrawal Capacity; European Yield Model (EYM) eISSN: 2398-4287© 2021. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians/Africans/Arabians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia. DOI: https://doi.org/10.21834/ebpj.v6iSI4.3030

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.

Comparative Research on Mechanical Behavior of Column-Bracing System between Fixed-Ended and Pin-Ended Column Base

2011 ◽  
Vol 250-253 ◽  
pp. 2519-2523
Author(s):  
Jin You Zhao ◽  
Yao Chun Zhang ◽  
Xun Guo
Keyword(s):  
Mechanical Behavior ◽  
Carrying Capacity ◽  
Ultimate Load ◽  
Initial Imperfection ◽  
Load Carrying Capacity ◽  
The Monte Carlo Method ◽  
Load Carrying ◽  
Ultimate Load Carrying Capacity ◽  
Bracing System ◽  
Column Base

In order to investigate the different mechanical behavior of column-bracing system between fixed-ended and pin-ended column base, a large number of column-bracing systems with fixed-ended and pin-ended column base were studied using the ANSYS program, in which random combination of the initial imperfections between columns and braces was well considered by the Monte Carlo method. Based on the above comparative study, probability density function of the bracing force was found through probability statistics and the design bracing force is obtained. The results show that the ultimate load-carrying capacity and the bracing forces of the mid-height horizontal braces of column-bracing systems with pin-ended column base are higher than that of column-bracing systems with fixed-ended column base, and the higher ultimate load-carrying capacity of the former more significantly increases the bracing forces of the mid-height horizontal braces; that the bracing forces of the mid-height horizontal braces in compression or in tension have also randomness because of the randomness of the initial imperfection of both columns and braces.

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