scholarly journals Experimental Investigation and Load Capacity of Slender Cold-Formed Lipped Channel Sections with Holes in Compression

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Xingyou Yao
Keyword(s):  
Parametric Study ◽  
Load Capacity ◽  
Fe Model ◽  
Building Structures ◽  
Test Results ◽  
Compression Tests ◽  
Axial Strength ◽  
Comparison Results ◽  
Study Results ◽  
Global Buckling

The use of cold-formed steel (CFS) channels with circular or rectangular web holes is becoming increasingly popular in building structures. However, such holes can result in sections becoming more susceptible to buckle and display lower load-carrying capacities. This paper presents a total of 42 axial compression tests of CFS lipped channel slender columns with and without circular and rectangular web holes, including different hole sizes and cross sections. The test results show that the axial members with a small ratio of width to thickness were governed by global buckling, while the members with a large ratio of width to thickness were controlled by the interaction of local, distortional, and global buckling. The axial strength decreased maximum by 20.48% and 22.98% for the member with circular holes and rectangular holes, compared to a member without a web hole. Then, a nonlinear elastoplastic finite element model (FEM) was developed, and the analysis results showed good agreement with the test results. The validated FE model was used to conduct a parametric study involving 36 FEMs to investigate the effects of column slenderness, dimension of the hole, and the number of holes on the axial strength of such channels. Furthermore, the formulas to predict the global buckling coefficient and the effective area were modified for such sections with holes by using the verified FEM. Finally, the tests and parametric study results were compared against the design strengths calculated in accordance with the developed method. The comparison results show that the proposed design method closely predicts the axial capacity of CFS channels with circular or rectangular web holes.

scholarly journals Distortional buckling behavior and design method of cold-formed steel lipped channel with rectangular holes under axial compression

2021 ◽  
Vol 18 (5) ◽  
pp. 6239-6261
Author(s):  
Yanli Guo ◽  
◽  
Xingyou Yao ◽  
Keyword(s):  
Parametric Study ◽  
Design Method ◽  
Fe Model ◽  
Building Structures ◽  
Test Results ◽  
Distortional Buckling ◽  
Comparison Results ◽  
Study Results ◽  
Load Carrying ◽  
Cold Formed Steel

<abstract> <p>The use of cold-formed steel (CFS) channel sections with rectangular holes in the web is becoming gradually popular in building structures. However, such holes can result in sections becoming more susceptible to be distortional buckling and display lower load-carrying capacities. This paper presents a total of 44 axially-compressed tests of CFS lipped channel columns with and without rectangular web holes including different hole sizes and cross-sections. The test results show that the specimens were controlled by distortional buckling or interaction of local buckling and distortional buckling. The load-carrying capacities of specimens with rectangular holes were lower than that of specimens without hole. The load-carrying capacities of specimens were gradually decreased with the increasing of dimensions of holes. Then a nonlinear elasto-plastic finite element model (FEM) was developed and the analysis results showed good agreement with the test results. The validated FE model was used to conduct a parametric study involving 16 FEM to investigate the effects of the section, the dimension of the hole, and the number of holes on the ultimate strength of such channels. Furthermore, the formulas to predict the distortional buckling coefficient were developed for the section with holes by using the verified FEM. Finally, the tests and parametric study results were compared against the distortional buckling design strengths calculated in accordance with the developed method. The comparison results show that the proposed design method closely predict the load carrying capacity of CFS channel sections with rectangular web holes.</p> </abstract>

scholarly journals Behavior of an Advanced Bolted Shear Connector in Prefabricated Steel-Concrete Composite Beams

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2958 ◽  
Author(s):  
Jun Chen ◽  
Wei Wang ◽  
Fa-Xing Ding ◽  
Ping Xiang ◽  
Yu-Jie Yu ◽  
...  
Keyword(s):  
Composite Structures ◽  
Concrete Slab ◽  
Concrete Strength ◽  
High Strength ◽  
Fe Model ◽  
Building Structures ◽  
Shear Connector ◽  
Test Results ◽  
Shear Connectors ◽  
Bolt Pretension

The high-strength bolt shear connector in prefabricated concrete slab has advantages in applications as it reduces time during the construction of steel-concrete composite building structures and bridges. In this research, an innovative and advanced bolt shear connector in steel-concrete composite structures is proposed. To investigate the fundamental mechanical behavior and the damage form, 22 static push-off tests were conducted with consideration of different bolt dimensions, the reserved hole constraint condition, and the dimension of slab holes. A finite element (FE) model was established and verified by using test results, and then the model was utilized to investigate the influence of concrete strength, bolt dimension, yield strength, bolt pretension, as well as length-to-diameter ratio of high strength bolts on the performances of shear connectors. On the basis of FE simulation and test results, new design formulas for the calculation of shear resistance behavior were proposed, and comparisons were made with current standards, including AISC, EN 1994-1-1, GB 50017-2017, and relevant references, to check the calculation efficiency. It is confirmed that the proposed equation is in better agreement with the experimental results.

A Method for Calculating Cracking Moment of FRP Reinforced Concrete Beam

2021 ◽  
Vol 896 ◽  
pp. 141-147
Author(s):  
Duy Nguyen Phan
Keyword(s):  
Reinforced Concrete ◽  
Modulus Of Elasticity ◽  
Parametric Study ◽  
Concrete Beams ◽  
Reinforced Concrete Beam ◽  
Reinforcement Ratio ◽  
Reinforced Concrete Beams ◽  
Comparison Results ◽  
Study Results ◽  
Frp Reinforcement

This paper presents an analytical method for calculating the cracking moment of concrete beams reinforced with fiber reinforced polymer (FRP) bars, which considers the non-linear behavior of concrete in the tension zone and the contribution of FRP reinforcement. Theoretical cracking moments obtained by the proposed method were verified with the experimental results and the theoretical results calculated according to ACI 440.1R-15. The comparison results show good agreement between theoretical and experimental data. A parametric study on the effect of longitudinal FRP reinforcement ratio and elastic modulus of FRP on the cracking moment of FRP reinforced concrete beams also were done by using the proposed method. The parametric study results show that both longitudinal reinforcement and modulus of elasticity of FRP significantly affect the cracking moment of FRP reinforced concrete beams. Moreover, parametric study results also clarify the weakness of ACI 440.1R-15 in determining the cracking moment of concrete beams reinforced with a large amount of FRP reinforcement ratio and with high modulus of elasticity of FRP.

Development of Simple Design-Oriented Procedure for Predicting the Collision Damage of FPSO Caisson Protection Structures

2010 ◽  
Author(s):  
Sang-Rai Cho ◽  
Jang-Hyun Jeong ◽  
Paul A. Frieze
Keyword(s):  
Structural Design ◽  
Parametric Study ◽  
Design Stage ◽  
Test Results ◽  
Simple Analytical Expression ◽  
Study Results ◽  
Commercial Package ◽  
Non Linear ◽  
Modification Factor ◽  
Protection Structures

Protection structures for FPSO caissons are required to be strong enough not to contact caisson pipes even when the protection structure is damaged by impact by attendant vessels. In the present structural design process, non-linear commercial packages are employed for the collision analyses. However, non-linear collision analyses using commercial packages are still time-consuming and expensive to operate especially at the initial design stage. In this study, validation of the adopted commercial package was firstly performed using collision test results on unstiffened tubulars. Then, a rigorous parametric study was conducted on simple protection structures by changing the collision velocity and the scantling of the protection structure. A simple analytical expression was derived assuming that the kinetic energy of the striking vessel is dissipated by plastic elongation of tubulars and rotation of plastic hinges. Using the parametric study results, an equation for the modification factor was obtained by which the effects of local denting and dynamic behavior can be considered. The developed procedure was also substantiated using numerically predicted extent of damages of an actual protection structure.

Characterization of Alkali-Treated Banana Fiber and its Effects as Web Reinforcement on the Axial Load Capacity of Concrete

2020 ◽  
Vol 853 ◽  
pp. 126-130
Author(s):  
Aiman A. Kamal ◽  
Manny Anthony M. Taguba ◽  
Anne Mica G. Marasigan ◽  
Rhobin M. Samonte ◽  
Aldrin N. Bata ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Parametric Study ◽  
Load Capacity ◽  
Construction Materials ◽  
The Philippines ◽  
Agricultural Wastes ◽  
Banana Fiber ◽  
Study Results ◽  
Web Reinforcement

The Philippines is an agricultural country due to its location in the tropics. Because of this nature, the agriculture sector tends to produce a huge amount of waste that if not disposed properly could pose a threat to the society and to the environment. Studies have been performed on the possibilities of incorporating agricultural wastes to various construction materials as a form of waste diversion. In order to address the problem with agricultural wastes as well as to improve the property of construction materials, a study on alkali-treated banana fiber as web reinforcement in concrete was done. In this study, a characterization of alkali-treated banana fiber was done in order to assess the characteristics of a possible reinforcement for concrete by tensile strength test on the fiber. The applicability of the treated fiber was then examined as a web reinforcement in concrete in terms of its load capacity. The parametric study was conducted to investigate the effect on the compressive strength of varying bundle diameter (4 mm, 8 mm, 12 mm, 16 mm) while holding the spacing of mesh at 20 mm and also the effect of varying mesh spacing (10 mm, 15 mm, 20 mm and 25 mm) while holding the diameter at 16 mm. Test results show that the 4 mm diameter of treated banana fiber yielded the highest tensile strength at 314 N compared to only 197 N of the untreated banana fiber. The parametric study results the diameter of banana fiber indicate that the increase in diameter also results in the increase in load capacity. With respect to spacing, the smaller the value of spacing results in higher load capacity.

Experimental and finite element study of optimal designed steel corrugated web beams

2021 ◽  
pp. 136943322098609
Author(s):  
Ferhat Erdal ◽  
Osman Tunca ◽  
Serkan Tas ◽  
Ramazan Ozcelik
Keyword(s):  
Load Capacity ◽  
Fe Model ◽  
Test Results ◽  
Long Span ◽  
Corrugated Web ◽  
Steel Sections ◽  
Experimental Process ◽  
Firefly Optimization ◽  
Concentrated Loading ◽  
Corrugated Steel Web

The structural performance of standard steel sections in long-span constructions gradually deteriorates due to wider and slighter webs that tend to buckle. This is the characteristic problem of plane webs. Corrugated steel web plates allow a considerable reduction of weight and increasing the web capacity of the beam. The experimental test results of optimal designed corrugated web beams, fortifying thin-walled steel girders without stiffeners, under load conditions, have been compared with the 3-D plane strains finite elements ( FE) model in this paper. The span of fabricated corrugated web beams ( CWB) is chosen as 5 m. These optimally designed CWB are exposed to a single concentrated loading, two-point loading, and partially distributed loading, respectively. The design methods for CWB are firefly optimization and hunting search algorithms. The implementation of design constraints is based on the EUROCODE, DIN, and DAST-Ri. 015 code provisions. The load-displacement curves, the residual load capacity, and the failure form of eighteen tested corrugated web beams are inquired in depth along the experimental process. The structural analysis software ANSYS is used for the simulation of the experimental study, the verification of all test results, and the investigation of the behavior of failure forms.

scholarly journals An experimental study on the structural performance of reinforced concrete low-rise building columns subjected to axial loading

2020 ◽  
Vol 14 (1) ◽  
pp. 103-111
Author(s):  
Pham Xuan Dat ◽  
Nguyen Anh Vu
Keyword(s):  
Reinforced Concrete ◽  
Axial Load ◽  
Load Capacity ◽  
Axial Loading ◽  
Structural Performance ◽  
Building Structures ◽  
Test Results ◽  
Structural Elements ◽  
Axial Load Capacity ◽  
Geometrical Dimensions

It has been commonly recognized by the international research and practice community that the presence of both outer and inner stirrups may significantly enhance the axial load capacity of reinforced concrete (RC) columns. However, there is limited testing evidence to support this conclusion that has been published nationally. This paper reports an experimental programme to study the effectiveness of stirrup detailing on the structural performance of columns having small sectional dimensions that are common in low-rise building structures. Nine column specimens with the same geometrical dimensions of 220 mm x 220 mm x 880 mm in three batches were detailed with different stirrup categories, have been gradually axially loaded to failure. The test data have revealed that although the presence of stirrups can generally enhance the axial load capacity of the column specimens, the enhancing levels are much dependent to the shapes of the stirrups. Selected interesting aspects of the test results have also been discussed, which set a concrete base for recommendations for design and detailing of such vertical structural elements. Keywords: experimental investigation; low-rise building columns; axial load capacity; stirrups.

scholarly journals Assessment of Lacrimal Duct Patency in Patients Undergoing Endoscopic Medial Maxillectomy

2021 ◽  
Vol 10 (2) ◽  
pp. 245
Author(s):  
Andrzej Sieśkiewicz ◽  
Tomasz Łysoń ◽  
Marek Rogowski ◽  
Marek Bielecki ◽  
Ewa Gindzienska-Sieskiewicz ◽  
...  
Keyword(s):  
Assessment Method ◽  
Test Results ◽  
Functional Disorders ◽  
Lacrimal Duct ◽  
Assessment Tests ◽  
Number Of Patients ◽  
Study Results ◽  
Assessment Techniques ◽  
Medial Maxillectomy ◽  
Comparison Of The Results

Purpose: The risk of epiphora after medial maxillectomy with lacrimal duct transection is difficult to assess. The data available in the literature are inconclusive due to various operating techniques used by the authors of medical publications, different additional procedures aimed at improving tear drainage after maxillectomy, and a variety of lacrimal duct patency assessment techniques. The aim of our work was to assess the anatomical and functional patency of lacrimal ducts after medial maxillectomy without performing additional procedures to improve tear drainage as well as comparison of the results obtained with different assessment tests. Materials and methods: 21 patients who underwent medial maxillectomy in the years 2016–2019 were assessed for discomfort and epiphora based on patients’ own reports and basic clinical examination, lacrimal duct rinse test, the Munk score, and a modified endoscopic Jones I test. Results: Gradually increasing the sensitivity of the assessment method resulted in an increase in the number of patients with potential tear drainage disorders, starting from 0% in the rinsing test, 4.8% self-reported tearing complaints, 14.3% Munk score, and 19% modified endoscopic Jones I test. Conclusions: The study results revealed that a small fraction of patients tend to report epiphora as a consequence of medial maxillectomy themselves. Subtle functional disorders, which are not particularly bothersome to patients, are more common. More sensitive lacrimal duct patency tests reveal more cases of tear drainage disorders. The results of studies assessing the incidence of epiphora after medial maxillectomy appear to depend on the type of test used.

scholarly journals Confinement effects for rubberised concrete in tubular steel cross-sections under combined loading

2021 ◽  
Vol 21 (2) ◽  
Author(s):  
A. Mujdeci ◽  
D. V. Bompa ◽  
A. Y. Elghazouli
Keyword(s):  
Axial Compression ◽  
Cross Section ◽  
Cross Sections ◽  
Image Correlation ◽  
Combined Loading ◽  
Test Results ◽  
Compression Tests ◽  
Confinement Effects ◽  
Rubber Content ◽  
Dependent Modification

AbstractThis paper describes an experimental investigation into confinement effects provided by circular tubular sections to rubberised concrete materials under combined loading. The tests include specimens with 0%, 30% and 60% rubber replacement of mineral aggregates by volume. After describing the experimental arrangements and specimen details, the results of bending and eccentric compression tests are presented, together with complementary axial compression tests on stub-column samples. Tests on hollow steel specimens are also included for comparison purposes. Particular focus is given to assessing the confinement effects in the infill concrete as well as their influence on the axial–bending cross-section strength interaction. The results show that whilst the capacity is reduced with the increase in the rubber replacement ratio, an enhanced confinement action is obtained for high rubber content concrete compared with conventional materials. Test measurements by means of digital image correlation techniques show that the confinement in axial compression and the neutral axis position under combined loading depend on the rubber content. Analytical procedures for determining the capacity of rubberised concrete infilled cross-sections are also considered based on the test results as well as those from a collated database and then compared with available recommendations. Rubber content-dependent modification factors are proposed to provide more realistic representations of the axial and flexural cross-section capacities. The test results and observations are used, in conjunction with a number of analytical assessments, to highlight the main parameters influencing the behaviour and to propose simplified expressions for determining the cross-section strength under combined compression and bending.

scholarly journals Behavior of Offshore Pile in Calcareous Sand—Case Study

2021 ◽  
Vol 9 (8) ◽  
pp. 839
Author(s):  
Tarek N. Salem ◽  
Nadia M. Elkhawas ◽  
Ahmed M. Elnady
Keyword(s):  
Load Capacity ◽  
High Stress ◽  
Embedment Depth ◽  
Shear Stresses ◽  
Northern Coast ◽  
Compression Tests ◽  
Calcareous Sand ◽  
Element Analysis ◽  
Mixing Ratios

The erosion of limestone and calcarenite ridges that existed parallel to the Mediterranean shoreline forms the calcareous sand (CS) formation at the surface layer of Egypt's northern coast. The CS is often combined with broken shells which are considered geotechnically problematic due to their possible crushability and relatively high compressibility. In this research, CS samples collected from a site along the northern coast of Egypt are studied to better understand its behavior under normal and shear stresses. Reconstituted CS specimens with different ratios of broken shells (BS) are also investigated to study the effect of BS ratios on the soil mixture strength behavior. The strength is evaluated using laboratory direct-shear and one-dimensional compression tests (oedometer test). The CS specimens are not exposed to significant crushability even under relatively high-stress levels. In addition, a 3D finite element analysis (FEA) is presented in this paper to study the degradation offshore pile capacity in CS having different percentages of BS. The stress–strain results using oedometer tests are compared with a numerical model, and it gave identical matching for most cases. The effects of pile diameter and embedment depth parameters are then studied for the case study on the northern coast. Three different mixing ratios of CS and BS have been used, CS + 10% BS, CS + 30% BS, and CS + 50% BS, which resulted in a decrease of the ultimate vertical compression pile load capacity by 8.8%, 15%, and 16%, respectively.

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