scholarly journals Laboratory and Numerical Analysis of Steel Cold-Formed Sigma Beams Retrofitted by Bonded CFRP Tapes

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4339 ◽  
Author(s):  
Ilona Szewczak ◽  
Katarzyna Rzeszut ◽  
Patryk Rozylo ◽  
Sylwester Samborski
Keyword(s):  
Numerical Analysis ◽  
Numerical Models ◽  
Load Capacity ◽  
Steel Structures ◽  
Bottom Flange ◽  
Building Structures ◽  
Inner Surface ◽  
Carbon Fibre Reinforced Polymer ◽  
Thin Walled ◽  
The Impact

In this paper, the retrofitting method of thin-walled, cold-formed sigma beams using bonded carbon fibre reinforced polymer (CFRP) tapes is proposed. The effectiveness of the presented strengthening method is investigated by the means of laboratory tests and numerical analysis conducted on simply supported, single-span beams made of 200 × 70 × 2 profile by “Blachy Pruszyński” subjected to a four-point bending scheme. Special attention is paid to the evaluation of possibility to increase the load capacity with simultaneous limitation of beams displacements by appropriate location of CFRP tapes. For this purpose, three beams were reinforced with CFRP tape placed on the inner surface of the upper flange, three with CFRP tape on the inner surface of the web, three beams with reinforcement located on the inner surface of the bottom flange, and two beams were tested as reference beams without reinforcement. CFRP tape with a width of 50 mm and a thickness of 1.2 mm was used as the reinforcement and was bonded to the beams by SikaDur®-30 adhesive. Precise strain measurement was made using electrofusion strain gauges, and displacement measurement was performed using two Aramis coupled devices in combination with the Tritop machine. Numerical models of the considered beams were developed in the Finite Element Method (FEM) program Abaqus®. Experimental and numerical analysis made it possible to obtain a very high agreement of results. Based on the conducted research, it was proved how important is the impact of the applied reinforcement (CFRP tapes) in thin-walled steel structures, with respect to the classic methods of strengthening steel building structures.

scholarly journals Laboratory and Numerical Analysis of Steel Cold-Formed Sigma Beams Retrofitted by Bonded CFRP Tapes—Extended Research

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4960
Author(s):  
Ilona Szewczak ◽  
Katarzyna Rzeszut ◽  
Patryk Rozylo ◽  
Malgorzata Snela
Keyword(s):  
Laboratory Tests ◽  
Numerical Models ◽  
Main Idea ◽  
Steel Beams ◽  
Bottom Flange ◽  
Large Rotation ◽  
Thin Walled Structures ◽  
Four Point Bending ◽  
Thin Walled ◽  
The Impact

The presented research is a part of a broader study of strengthening methods closely associated with cold-formed sigma steel beams with tapes made of Carbon Fiber Reinforcement Polymer/Plastic (CFRP). The presented results are a continuation and extension of the tests described in previous work by the authors and refer to high-slenderness thin-walled steel sigma beams subjected to a significant large rotation. The main idea of this expanded study was to identify the effectiveness of CFRP tapes with respect to different locations, namely at a bottom-tensioned or upper-compressed flange. Six beams with a cross-section of an Σ140 × 70 × 2.5 profile by “Blachy Pruszyński” and made of S350GD steel with a span of L = 270 cm were tested in the four-point bending scheme. Two beams, taken as reference, were tested without reinforcement. The remaining beams were reinforced with the use of a 50-mm wide and 1.2-mm thick Sika CarboDur S512 CFRP tape, with two beams reinforced by placing the tape on the upper flange and two with tape located on the bottom flange. The CFRP tape was bonded directly to the beams (by SikaDur®-30 adhesive). Laboratory tests were aimed at determining the impact of the use of composite tapes on the limitation of displacements and deformations of thin-walled structures. In order to perform a precise measurement of displacement, which is, in the case of beams subjected to large rotations, a very difficult issue in itself, the Tritop system and two coupled lenses of the Aramis system were used. Electrofusion strain gauges were used to measure the deformation. In the next step, numerical models of the analyzed beams were developed in the Abaqus program. Good compliance of the results of laboratory tests and numerical analyses was achieved. The obtained results confirm the beneficial effect of the use of tapes (CFRP) on the reduction in displacements and deformations of steel cold-formed elements.

scholarly journals Test-supported numerical analysis for evaluation of the load capacity of thin-walled corrugated profiles

2017 ◽  
Vol 65 (6) ◽  
pp. 791-798
Author(s):  
A. Piekarczuk
Keyword(s):  
Numerical Analysis ◽  
Cold Rolling ◽  
Quantitative Evaluation ◽  
Comparative Evaluation ◽  
Load Capacity ◽  
Computational Method ◽  
Building Structures ◽  
Internal Forces ◽  
Thin Walled ◽  
Natural Scale

Abstract The paper concentrates on a quantitative evaluation of the load capacity of thin-walled, curved steel profiles used as arched roofs in building structures. Corrugation of a profile surface formed by cold rolling changes its load capacity as compared to thin-walled profiles. The paper presents a comparative evaluation of the influence of a sample profile corrugation on its ability to transfer internal forces. The results of the study are presented as limit curves describing load capacity at simultaneous bending and compression. The analysis was conducted using a numerical computational method supported by a study of elements in natural scale. The paper presents a methodology of test-supported calculations and guidelines for practical use by designers.

Mechanical Properties Prediction for Cold-formed Steel Angle Connection with Various Flange Cleat Thickness

2015 ◽  
Vol 74 (4) ◽  
Author(s):  
Yeong Huei Lee ◽  
Cher Siang Tan ◽  
Shahrin Mohammad ◽  
Yee Ling Lee
Keyword(s):  
Mechanical Properties ◽  
Numerical Models ◽  
Steel Structures ◽  
Rotational Stiffness ◽  
Steel Angle ◽  
Cold Formed Steel ◽  
Mechanical Properties Prediction ◽  
Thin Walled ◽  
Angle Connection ◽  
Hot Rolled

Connection is an important element in structural steelwork construction. Eurocode does not provide adequate design information for mechanical properties prediction of top-seat flange cleat connection, especially for thin-walled cold-formed steel structures. Adopting hot-rolled design with neglecting thin-walled behaviour could lead to unsafe or uneconomic design. This research aims to provide accurate mechanical properties prediction for bolted top-seat flange cleat connection in cold-formed steel structures. The scope of work focuses on the effect of various thickness of the flange cleat to the rotational stiffness and strength behaviour of a beam-to-column connection. Experimentally verified and validated finite element modelling technique is applied in the parametric investigation. Two categories of flange cleat thickness, ranged from 2 mm to 40 mm are studied. From the developed numerical models, it is observed that Eurocode has overestimated the initial rotational stiffness prediction, calculated with component method. The over-estimation would influence the overall stiffness of structures and force distribution within the components. As a conclusion, a set of newly proposed accurate predictions for initial rotational stiffness and strength of cold-formed steel top-seat flange cleat connection, with the influence of the thickness of flange cleat is presented.

scholarly journals Study on Calculation of Bearing Capacity of Axially Loaded CFRP-Strengthened Cold-Formed Thin-Walled Lipped Channel Steel Columns

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Yanan Sun ◽  
Pengfei Li ◽  
Guojin Qin
Keyword(s):  
Carbon Fiber ◽  
Bearing Capacity ◽  
Load Capacity ◽  
Slenderness Ratio ◽  
Steel Structures ◽  
Fiber Reinforced ◽  
Bonding Agents ◽  
Steel Column ◽  
Thin Walled ◽  
Carbon Fiber Reinforced

With the development of carbon fiber reinforced composites and the continuous improvement of the properties of bonding agents, scholars recommended using carbon fiber reinforced plastics (CFRP) to enhance cold-formed thin-walled C-shaped steel structures. It can provide a fast and effective way to strengthen and repair damaged steel structures. However, discussion on the bearing capacity calculation of cold-formed thin-walled C-section steel column strengthened by CFRP was limited. Also, the relevant influencing factors (the number of CFRP reinforcement layers), the orientation of CFRP (horizontal, vertical), and the location of CFRP reinforcement (web + flanges + lips, web + flanges, web, and flanges) were overlooked in calculating the bearing capacity of cold-formed thin-walled C-section steel column strengthened by CFRP. Then, the calculation result of the load capacity will be inaccurate. This work, therefore, studied the effects of CFRP reinforcement layers, CFRP direction, and CFRP reinforcement position on the ultimate load of CFRP-strengthened cold-formed thin-walled C-section steel column. A three-dimensional (3D) finite element model of cold-formed thin-walled steel strengthened by CFRP was established to discuss the bearing capacity under axial compression. Furthermore, a method for calculating the bearing capacity of the CFRP-strengthened cold-formed thin-walled C-section steel column was proposed based on the direct strength methods (DSM). The results indicate that not only the slenderness ratio, section size, and length of members but also the number of CFRP reinforcement layers and orientation of CFRP have an impact on the calculation of bearing capacity. The equation modified in this work has excellent accuracy and adaptability. Predicting the bearing capacity of reinforced members is necessary to give full play to the performance of CFRP accurately. Thus, the methods proposed can provide a reference value for practical engineering.

scholarly journals Influence of boundary conditions in FEM model on structural behaviour of thin-walled steel beams strengthened by CFRP tapes

2020 ◽  
Vol 19 (2) ◽  
pp. 073-086
Author(s):  
Katarzyna Rzeszut ◽  
Ilona Szewczak ◽  
Patryk Rozylo
Keyword(s):  
Boundary Conditions ◽  
Laboratory Tests ◽  
Numerical Models ◽  
Load Capacity ◽  
Steel Beams ◽  
Structural Behaviour ◽  
Fem Model ◽  
Mesh Density ◽  
Newton Raphson ◽  
Thin Walled

The main aim of the study is verification and validation of FEM numerical model of beams made of thin-walled steel profiles retrofitted by CFRP tapes Sika CarboDur S. Validation is are carried out based on own laboratory tests conducted on “Blachy Pruszyński” S-type beams. The CFRP tape are bonded to the beam at compressed or tensioned flange. The most important part of this study is focused on investigation of boundary conditions influence in FEM model developed in Abaqus program. Moreover the numerical models are also tested in terms of different mesh density and types of finite elements. Numerical analyses are carried out using Newton-Raphson iterative method to solve non-linear equilibrium equation. In the paper special attention is paid to the evaluation of the possibility to increase the load capacity of the beams by appropriate localisation of CFRP tape.

Numerical Analysis of the Influence of the Parameter of Ductility of Reinforcing Steel on the Behaviour of Narrow Three-Span Reinforced Concrete Slabs from the Point of View of Experimental Investigations

2015 ◽  
Vol 769 ◽  
pp. 133-138
Author(s):  
Mirosław Wieczorek
Keyword(s):  
Reinforced Concrete ◽  
Numerical Analysis ◽  
Laboratory Tests ◽  
Numerical Models ◽  
Material Model ◽  
Point Of View ◽  
Experimental Investigations ◽  
Concrete Slabs ◽  
Building Structures ◽  
Reinforced Concrete Slabs

In the time of exploitation of building structures frequently situations do occur, in which due to failures they are exposed to much higher loads than originally predicted. The subject matter of the performed investigations and a numerical analysis are models of four narrow reinforced concrete slabs with the dimensions 7140×500×190 mm. The paper presents the results of the numerical analysis, the aim of which was to reflect and to provide detailed information about phenomena occurring in the course of laboratory tests. Numerical models were constructed according to the system ANSYS, applying volumetric elements SOLID65 and bars LINK8. In order to determine the relation σ-ε of steel an isotropic model of strengthening in the system ANSYS was used, constructed by Misses. The behaviour of concrete was represented by the material model Concrete. The parameters applied in the material models had been obtained in laboratory tests of the material. The paper quotes the results of calculations compared with the results obtained in laboratory tests.

scholarly journals Fem and Experimental Analysis of Thin-Walled Composite Elements Under Compression

2017 ◽  
Vol 22 (2) ◽  
pp. 393-402 ◽  
Author(s):  
P. Różyło ◽  
P. Wysmulski ◽  
K. Falkowicz
Keyword(s):  
Numerical Analysis ◽  
Cross Section ◽  
Numerical Models ◽  
Fem Analysis ◽  
Geometrical Parameters ◽  
Loss Of Stability ◽  
Composite Columns ◽  
Thin Walled Structures ◽  
Operating Stability ◽  
Thin Walled

Abstract Thin-walled steel elements in the form of openwork columns with variable geometrical parameters of holes were studied. The samples of thin-walled composite columns were modelled numerically. They were subjected to axial compression to examine their behavior in the critical and post-critical state. The numerical models were articulately supported on the upper and lower edges of the cross-section of the profiles. The numerical analysis was conducted only with respect to the non-linear stability of the structure. The FEM analysis was performed until the material achieved its yield stress. This was done to force the loss of stability by the structures. The numerical analysis was performed using the ABAQUS® software. The numerical analysis was performed only for the elastic range to ensure the operating stability of the tested thin-walled structures.

scholarly journals Experimental and Numerical Evaluation of Clinch Connections of Thin-Walled Building Structures

2020 ◽  
Vol 12 (14) ◽  
pp. 5691
Author(s):  
Jakub Flodr ◽  
Petr Lehner ◽  
Martin Krejsa
Keyword(s):  
Numerical Model ◽  
Energy Intensity ◽  
Reliability Assessment ◽  
Steel Structures ◽  
High Energy ◽  
Basic Material ◽  
Building Structures ◽  
The Press ◽  
Thin Walled ◽  
Computational Procedures

The high energy intensity of industry and the importance of natural resources are currently much-discussed topics. Light steel structures made from thin-walled cold-formed (TWCF) profiles play an important role in this discussion because their increased use has significantly reduced the consumption of conventional structural steel. New, more efficient technologies for connections of the TWCF structures, such as punch riveting and clinching, are being developed, which are advantageous in terms of cost and time. An innovative way to obtain the physical properties of a clinch joint and instructions for a detailed reliability assessment of this type of connection is described in this article. The resulting behaviour of the numerical model based on the tensile test of the basic material and suitable boundary conditions was validated by a physical experiment. The computational procedures presented in the article will facilitate the design of steel structures in the field of global static analysis of TWCF light steel structures because the described methods can be generalised and applied in commonly available commercial software. Two variants of the model were prepared and evaluated—with and without slippage in the press jaws. Comparison of the numerical model and experimental results shows compliance.

scholarly journals Improving Blast Performance of Reinforced Concrete Panels Using Sacrificial Cladding with Hybrid-Multi Cell Tubes

Modelling ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 149-165
Author(s):  
Mahmoud Abada ◽  
Ahmed Ibrahim ◽  
S.J. Jung
Keyword(s):  
Reinforced Concrete ◽  
Numerical Models ◽  
Plate Thickness ◽  
Core Layer ◽  
Engineering Structures ◽  
Finite Element Program ◽  
Explicit Finite Element ◽  
Element Program ◽  
Thin Walled ◽  
The Impact

The utilization of sacrificial layers to strengthen civilian structures against terrorist attacks is of great interest to engineering experts in structural retrofitting. The sacrificial cladding structures are designed to be attached to the façade of structures to absorb the impact of the explosion through the facing plate and the core layer progressive plastic deformation. Therefore, blast load striking the non-sacrificial structure could be attenuated. The idea of this study is to construct a sacrificial cladding structure from multicellular hybrid tubes to protect the prominent bearing members of civil engineering structures from blast hazard. The hybrid multi-cell tubes utilized in this study were out of staking composite layers (CFRP) around thin-walled tubes; single, double, and quadruple (AL) thin-walled tubes formed a hybrid single cell tube (H-SCT), a hybrid double cell tube (H-DCT), and a hybrid quadruple cell tube (H-QCT). An unprotected reinforced concrete (RC) panel under the impact of close-range free air blast detonation was selected to highlight the effectiveness of fortifying structural elements with sacrificial cladding layers. To investigate the proposed problem, Eulerian–Lagrangian coupled analyses were conducted using the explicit finite element program (Autodyn/ANSYS). The numerical models’ accuracy was validated with available blast testing data reported in the literature. Numerical simulations showed a decent agreement with the field blast test. The proposed cladding structures with different core topologies were applied to the unprotected RC slabs as an effective technique for blast loading mitigation. Mid-span deflection and damage patterns of the RC panels were used to evaluate the blast behavior of the structures. Cladding structure achieved a desired protection for the RC panel as the mid-span deflection decreased by 62%, 78%, and 87% for H-SCT, H-DCT, and H-QCT cores, respectively, compared to the unprotected panels. Additionally, the influence of the skin plate thickness on the behavior of the cladding structure was investigated.

scholarly journals PROBABILISTIC ANALYSIS OF THERMAL PERFORMANCE OF THE WALL FROM LIGHT-GAUGE THIN-WALLED STEEL STRUCTURES

2017 ◽  
Vol 1 (48) ◽  
pp. 144-155
Author(s):  
S. F. Pichugin ◽  
V. O. Semko ◽  
M. V. Leshсhenko
Keyword(s):  
Heat Transfer ◽  
Steel Structures ◽  
Failure Criteria ◽  
Technical Failure ◽  
Thermal Reliability ◽  
Transfer Resistance ◽  
Thin Walled Structures ◽  
Wall Panels ◽  
Inner Surface ◽  
Thin Walled

The article is devoted to determining of the thermal reliability rates of CFS wall panels based on three thermo-technical failure criteria - reduced heat transfer resistance, exceeding the values of the temperature difference between the reduced temperature of the inner surface of structure and internal air temperature above the permissible temperature values by the sanitary requirements and criteria of reduction of local values of the inner surface temperature to the temperature of vapor-liquid condensation. With increasing coefficient of variation of thermal conductivity from 2.28% to 20%, the probability of refusal of wall panels of light steel thin-walled structures, under the criterion of the specified heat transfer resistance, is increasing from 9,85´10-7 to 0,015 respectively.

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