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

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.

Mechanika ◽  
2019 ◽  
Vol 25 (6) ◽  
pp. 426-433 ◽  
Author(s):  
Tao LAN

In this paper, load-carrying and deformation capacity of tension lap splices that have both welds and bolts acting in the same shear plane are studied using numerical method. The failure criterion of bolts and welds are given based on the finite element calculation and compared with existing experiment results, it shows that the established numerical model is correct and reliable. The strength of longitudinal welds and the bearing capacity of the high-strength bolts before slipping can be fully used in the combined joints, the bolts and welds fail almost simultaneously. The deformation of welds in combined connections is less uniform than its’ deformation in welded joints as the welds fails, and it causes the deformation of welds as failure is larger in combined connections than in welded connections. The deformation capacity of the combined joint are slightly increased contrasted with bolts joint and welds joint because of the interplay of bolts and welds acting in the same shear plane. The strengths of welds and bolts performed in combined connections can reach 0.95 and the deformation of combined connection is increased at least 1.10 times as the welds connection or the bolts connection.


2010 ◽  
Vol 163-167 ◽  
pp. 433-438
Author(s):  
Xian Lei Cao ◽  
Ji Ping Hao ◽  
Chun Lei Fan

To obtain a better understanding of the behavior and load-carrying capacity of Q460 high-strength single-angle compression members bolted by one leg, using static loading way to 48 angles carried out experimental study. The experiments show test specimens produce biaxial bending, most small slenderness ratio members are controlled by local buckling, and slender specimens are controlled by overall buckling. In addition to these factors in model experiment, influences of residual stresses on ultimate load-carrying capacity were analyzed by finite element numerical simulation analysis, the results show the residual stresses affect the ultimate load-carrying capacity of angles by about 5% or less. Comparison of the load-carrying capacity of experimental and theoretical results indicate the difference of experimental and finite element values ranges from -9.99% to +9.76%, American Design of Latticed Steel Transmission Structure (ASCE10-1997) and Chinese Code for Design of Steel Structures (GB50017-2003) underestimate separately the experimental load-carrying capacity by about 2.34%~33.93% and 1.18%~63.3%, and the agreement is somewhat good between experimental program and the finite element analysis. Based on model experiment and simulated experiment, the formula of stability coefficient of single-angle compression members was established. It provides basic data for spreading Q460 high-strength single-angles members attached by one leg.


In recent years the utilization of cold formed steel has been redoubled. This is because high strength to weight ratio of the cold formed steel. The thicknesses cold formed steel members usually range from 0.3 mm to 6.35 mm. The most used cold formed sections are C and Z sections. These sections can be used as secondary beams (purlins) for roof covering, side girts, decks, and panels. Scope of this present study is to investigate the effect on load carrying capacity of cold formed channel sections provided with flange stiffeners. In this project, eighteen numbers of channel sections were analysed by keeping the height to thickness ratio (h/t) as constant and by varying flange width to thickness ratio (b/t) using Ansys 14.0. The h/t ratio and b/t ratio considered are 50 and 25, 35, 45 respectively. The thickness and span of all specimens were kept as 2 mm and 1500 mm respectively. Simply supported boundary condition and two points loading was adopted for both the numerical and experimental analysis. Three numbers of channel sections were fabricated and tested experimentally to check the consistency of results with numerical analysis. The ultimate load and deformed shape of three specimens were obtained from experimental results are compared with the analytical results acquired from Ansys 14.0


2000 ◽  
Vol 122 (4) ◽  
pp. 243-252 ◽  
Author(s):  
So̸ren R. Hauch ◽  
Yong Bai

In this paper, the bending moment capacity for metallic pipes has been investigated to provide criteria for optimizing the cost effectiveness in pipeline seabed intervention design. An analytical solution for the ultimate load-carrying capacity of pipes subjected to combined pressure, longitudinal force, and bending has been derived and thoroughly compared against results obtained by the finite element method. The derived equations can be used for high-strength materials with isotropic as well as anisotropic stress/strain characteristics, and may be applied for pipelines, risers, and piping if safety factors are calibrated in accordance with appropriate target safety levels. [S0892-7219(00)00504-5]


2020 ◽  
Vol 38 (5A) ◽  
pp. 669-680
Author(s):  
Ghazwan K. Mohammed ◽  
Kaiss F. Sarsam ◽  
Ikbal N. Gorgis

The study deals with the effect of using Slurry infiltrated fiber concrete (SIFCON) with the reinforced concrete beams to explore its enhancement to the flexural capacity. The experimental work consists of the casting of six beams, two beams were fully cast by conventional concrete (CC) and SIFCON, as references. While the remaining was made by contributing a layer of SIFCON diverse in-depth and position, towards complete the overall depths of the built-up beam with conventional concrete CC. Also, an investigation was done through the control specimens testing about the mechanical properties of SIFCON. The results showed a stiffer behavior with a significant increase in load-carrying capacity when SIFCON used in tension zones. Otherwise high ductility and energy dissipation appeared when SIFCON placed in compression zones with a slight increment in ultimate load. The high volumetric ratio of steel fibers enabled SIFCON to magnificent tensile properties.


2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Rajinder Ghai ◽  
Prem Pal Bansal ◽  
Maneek Kumar

There is a common phenomenon of shear failure in RCC beams, especially in old buildings and bridges. Any possible strengthening of such beams is needed to be explored that could strengthen and make them fit for serviceable conditions. The present research has been made to determine the performance of predamaged beams strengthened with three-layered wire mesh polymer-modified ferrocement (PMF) with 15% styrene-butadiene-rubber latex (SBR) polymer. Forty-eight shear-designed and shear-deficient real-size beams were used in this experimental work. Ultimate shear load-carrying capacity of control beams was found at two different shear-span (a/d) ratios 1 and 3. The sets of remaining beams were loaded with different predetermined damage levels of 45%, 75%, and 95% of the ultimate load values and then strengthened with 20 mm thick PMF. The strengthened beams were then again tested for ultimate load-carrying capacity by conducting the shear load test at a/d = 1 and 3. As a result, the PMF-strengthened beams showed restoration and enhancement of ultimate shear load-carrying capacity by 5.90% to 12.03%. The ductility of strengthened beams was improved, and hence, the corresponding deflections were prolonged. On the other hand, the cracking pattern of PMF-strengthened beams was also improved remarkably.


Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3468
Author(s):  
Zbigniew Kolakowski ◽  
Andrzej Teter

The phenomena that occur during compression of hybrid thin-walled columns with open cross-sections in the elastic range are discussed. Nonlinear buckling problems were solved within Koiter’s approximation theory. A multimodal approach was assumed to investigate an effect of symmetrical and anti-symmetrical buckling modes on the ultimate load-carrying capacity. Detailed simulations were carried out for freely supported columns with a C-section and a top-hat type section of medium lengths. The columns under analysis were made of two layers of isotropic materials characterized by various mechanical properties. The results attained were verified with the finite element method (FEM). The boundary conditions applied in the FEM allowed us to confirm the eigensolutions obtained within Koiter’s theory with very high accuracy. Nonlinear solutions comply within these two approaches for low and medium overloads. To trace the correctness of the solutions, the Riks algorithm, which allows for investigating unsteady paths, was used in the FEM. The results for the ultimate load-carrying capacity obtained within the FEM are higher than those attained with Koiter’s approximation method, but the leap takes place on the identical equilibrium path as the one determined from Koiter’s theory.


2018 ◽  
Vol 22 (7) ◽  
pp. 1554-1565 ◽  
Author(s):  
Jianwei Tu ◽  
Kui Gao ◽  
Lang He ◽  
Xinping Li

At present, extensive studies have been conducted relative to the topic of fiber-reinforced polymer(FRP)- reinforced concrete (RC) flexural members, and many design methods have also been introduced. There have, however, been few studies conducted on the topic of FRP-RC compression members. In light of this, eight glass-fiber-reinforced polymer (GFRP)-RC square columns (200×200×600 mm) were tested in order to investigate their axial compression performance. These columns were reinforced with GFRP longitudinal reinforcement and confined GFRP stirrup. These experiments investigated the effects of the longitudinal reinforcement ratio, stirrup configuration (spirals versus hoops) and spacing on the load-carrying capacity and failure modes of GFRP-RC rectangular columns. The test results indicate that the load-carrying capacity of longitudinal GFRP bars accounted for 3%-7% of the ultimate load-carrying capacity of the columns. The ultimate load-carrying capacity of RC columns confined with GFRP spirals increased by 0.8%-1.6% with higher ductility, compared to GFRP hoops. Reducing the stirrup spacing may prevent the buckling failure of the longitudinal bars and increase the ductility and load-carrying capacity of the GFRP-RC columns. It has been found that setting the GFRP compressive strength to 35% of the GFRP maximum tensile strength yields a reasonable estimate of ultimate load-carrying capacity of GFRP-RC columns.


2003 ◽  
Vol 1845 (1) ◽  
pp. 191-199 ◽  
Author(s):  
Ondrej Kalny ◽  
Robert J. Peterman ◽  
Guillermo Ramirez ◽  
C. S. Cai ◽  
Dave Meggers

Stiffness and ultimate load-carrying capacities of glass fiber-reinforced polymer honeycomb sandwich panels used in bridge applications were evaluated. Eleven full-scale panels with cross-section depths ranging from 6 to 31.5 in. (152 to 800 mm) have been tested to date. The effect of width-to-depth ratio on unit stiffness was found to be insignificant for panels with a width-to-depth ratio between 1 and 5. The effect of this ratio on the ultimate flexural capacity is uncertain because of the erratic nature of core-face bond failures. A simple analytical formula for bending and shear stiffness, based on material properties and geometry of transformed sections, was found to predict service-load deflections within 15% accuracy. Although some factors influencing the ultimate load-carrying capacity were clearly identified in this study, a reliable analytical prediction of the ultimate flexural capacity was not attained. This is because failures occur in the bond material between the outer faces and core, and there are significant variations in bond properties at this point due to the wet lay-up process, even for theoretically identical specimens. The use of external wrap layers may be used to shift the ultimate point of failure from the bond (resin) material to the glass fibers. Wrap serves to strengthen the relatively weak core–face interface and is believed to bring more consistency in determining the ultimate load-carrying capacity.


2021 ◽  
Vol 28 (1) ◽  
pp. 71-83
Author(s):  
Mazin Abdulrahman ◽  
Shakir Salih ◽  
Rusul Abduljabbar

In this research, an experimental study is conducted to investigate the behavior and strength of high strength reinforced concrete corbels externally bonded with CFRP fabric sheets and Plates with different patterns taking into account the effect of adopted variables in enhancing the ultimate strength; the effect of shear span to effective depth (a/d), configuration, type and amount of bonding. Eleven high strength reinforced corbels were cast and tested under vertical loads. Test results showed there was an improvement in the behavior and load carrying capacity of all strengthened corbels. An increasing in the ultimate strength of strengthened corbel by inclined CFRP strips reached to (92.1%) while the increasing reached to (84.21%) for using one horizontal CFRP Plates compared to un-strengthened reference specimen. Also, it can be conducted that the increase of (a/d) ratio from (0.6 to 0.8) resulted in decreasing by 21.05% in ultimate load capacity of corbels and from (0.4 to 0.6) by 31.25% and 58.69% in cracking and ultimate loads respectively Using CFRP .


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