The modern basic civil engineering concept is to design simplistic structures, by using innovative brand new manufacturing and assemblage concepts. As a result of this concept, arch type steel plates are used like the corrugated coatings. The main purpose of this work is to describe the Roll Form Machine (RFM) technology as used for the structures, especially for the roofs. Cold formed arch type steel structures may be fast and simple. These types of structures were used for temporary buildings in the US Army. Nowadays, this technology becomes popular and gets in consideration for civil life. However, the design concept of this technology does not have a theoretical model, and the calculations are evaluated according to the United States Standards. The uniaxial compressive behaviors of corrugated arch type steel members are observed, experimentally within this work.

In today’s construction industry, the economic conditions are at the forefront, and fast-to-implement cheap solutions have become widespread. This has been evidenced by RFM (Roll Forming Machine) technology, especially in the light of the steel construction sector. With the machine called RFM, steel or aluminum sheet / sheet sections are inserted in a self-tapping fashion to produce k-span elements. The vault construction systems formed by means of joining and clamping the elements produced have become very common thanks to this technology. As an example, a k-span manufactured with this technology and produced in the United States of America is shown in Figure

k-span: super span model 600 a) corrugated b) without corrugation and the effective cross-section area in all models

For the construction of the k-span in the design, light steel sheets are transported to the building site via RFM truck for application on site. First, panels are manufactured and cut to get the required spacing. These panels are then given an accurate shape to form the designed arch, and brought together to form the structure. In the case of restricted data obtained from the literature, all calculations are made according to the relevant American Standards. However, this situation brings with it a number of limitations, especially since the different loads considered in European specifications are ignored. Furthermore, there is a lack of a suitable theoretical model for such lightweight steel elements, and the folding formations that occur during panels that can be bent into a belt include uncertainties [

Once the RFM has taken to the site on a track, the construction process can be carried out by a small group of trained personnel. The Figure

RFM machine

Panels are cut at the site, squeezed together with the sewing machine, secured to the lifting platform and transported to the application site with a crane. Figure

Application of arch steel plate sections (a-b-c-shows the application pf a k-span vault-type structure made of light steel plates on the site in the Afghanistan (

In this study, load-displacement and load-strain curves under axial load of two types of sectioned members made of light steel plate are investigated. In the first type, a non-feminine lightweight steel sheet section was investigated. The second type is the light steel plate section which is regarded as corrugated. Two types of models were obtained using RFM technology. Another point to note is that in both samples, there are parallel folds for the folding direction, while the second type corrugated vertically. In both types of members, the plate thickness is 0.6 mm, and the member height is 1200 mm. In this research, the k-span (super span model 600) is attempting to provide a basis for a better understanding of the dental (folding/bending) effect on panels. The coupon tension test of the structural steel material of the light steel plate were performed complying with UNE-EN 10002-1 [

All the models are manufactured from the same steel roll. Thus, the material properties are same for all and presented in Table

Experimental models a) without corrugation b) corrugated

Materials Properties

The Youngs Modulus |
The Yield Strength |
The ultimate tensile strength |
Poissons Ratio |
---|---|---|---|

201 | 352.8 | 489.6 | 0.29 |

This study was carried out at Atatürk University. The hydraulic jack was used here to assess the static load of the test models. The maximum load of the setup was 900 kN, which was employed with a maximum stroke of 300 mm, and a constant speed of 0.016 mm/s, up to the collapse of the specimens [

The experimental setup

Three tensile coupon tests were performed to obtain the shell material properties. Average yield strength was found 352.8 MPa. The Young’s modulus was calculated 201GPa, and the Poisson’s ratio was obtained 0.29. The analytical solution for the ultimate load of straight and corrugated panels is based on Eurocode 3 Part 1-5 [

The load-displacement curves are discussed, shown in Figures _{U}), first buckling load (P_{cr}) and displacement values for both experiments, but also gives comparative results for both experiments. The behaviors of axially loaded, with and without corrugated (super span model 600) members are investigated throughout this study. It is seen that the first buckling load of the member perpendicular to the load direction (orthogonal to horizontal load) is 1.59 times greater than the member perpendicular to the load (perpendicular to the load without vertical folding). Also, the load carrying capacity of the member perpendicular to the load direction (orthogonal to horizontal load) is 4.13 times greater than the member perpendicular to the load (perpendicular to the load without vertical folding) (Table _{cr}), and maximum load (P_{u}) of experimental model. Table _{cr}) of the models, they resisted the models themselves. They entered the stage of post-buckling. A fading effect is about 33.03% and 75.56% for the uncorrugated model and corrugated model, respectively. Thus, a fading effect of the corrugated model was greater than of the uncorrugated model. Furthermore, when the maximum load (P_{u}) of the experimental compared to analytical one from the EC3, the first buckling load (P_{cr}) of the uncorrugated experimental model is 0.039 times lower than the EC3 based one. And the first buckling load (P_{cr}) of the corrugated experimental model is 0.045 times lower than the EC3 based one. The maximum load (P_{u}) of the uncorrugated experimental model is 0.059 times lower than the analytical load of EC3. And the maximum load (P_{u}) of the corrugated experimental model is 0.178 times lower than the analytical load of EC3. Thus, Table _{cr}) and experimental maximum load (P_{u}). On the other hand, if anyone wants to get the first buckling load (P_{cr}) and the maximum load (P_{u}) times according to theoretical formulas, it must multiply the coefficients to obtain the first buckling load (P_{cr}) and the maximum load (P_{u}).

Load-displacement for uncorrugated member

Load-displacement for corrugated member

Load-displacement of the members with and without corrugate

Model | First bucking load |
First buckling load Displacement |
Max. load |
Displacement at Pu |
Max. Displacement |
First bucking load (Pcr) (EX2) / First bucking load (Pcr) |
Analytical Max.load of the EC3 |
Max. Load (EX2) / Max. Load |
First bucking load (Pcr) (EX)/Analytical Max.load of the EC3 | Max. load(Pu) (EX)/Analytical Max.load of the EC3 |
---|---|---|---|---|---|---|---|---|---|---|

EX1 |
2.30 | 31.72 | 3.4345 | 91.15 | 262.95 | 57.96 | 4.13 | 0.039 | 0.059 | |

EX2 |
3.649 | 1.84 | 14.1925 | 24.29 | 61.80 | 1.59 | 79.38 | 0.045 | 0.178 |

uncorrugated

corrugated

The load-strain curves are discussed and shown in Figures

Load-strain for the uncorrugated members

Load-strain for the corrugated member

The greatest stress of the sections of the arched steel plate can be evaluated as the flaw and lateral buckling sensitivity that can occur during construction. As shown in Fig.

Failure types of the all tests

In 2014, Cybulski et al. carried out some experiments on MIC120 models and the experimental results of this work are compared with the experimental results of Cybulski et al research in Table

Comparison of this work and Cybulski et al. [

Model | Experimental load (Cybulski et al [ |
First buckling load (Pcr) (kN) | Max. load (Pu) | First buckling load (Pcr) to Experimental load (Cybulski et al (%) | Max. load (Pu) to Experimental load (Cybulski et al (%) |
---|---|---|---|---|---|

EX1 |
- | 2.30 | 3.4345 | - | - |

EX2 |
- | 3.649 | 14.1925 | - | - |

S1 | 56.9 | - | - | 4.04 | 6.04 |

S2 | 57.5 | - | - | 4 | 5.97 |

S3 | 59.7 | - | - | 3.8 | 5.75 |

S1r5m | 44.6 | - | - | 8.18 | 31.82 |

S2r5m | 43.1 | - | - | 8.46 | 32.92 |

S3r5m | 44.3 | - | - | 8.24 | 32.04 |

uncorrugated

corrugated, S1,S2 and S3 are straight panels; and S1r5m, S2r5m, and S3r5m are corrugated panels of the Cybulski et al. [

For the uncorrugated models, Table _{cr}) to experimental load of the Cybulski et al were between 3.8% to 4.04% [_{cr}) to experimental load of the Cybulski et al were between 8.18% to 8.46% [_{cr}) to experimental load of the Cybulski et al is reasonable [

For the uncorrugated models, Table _{u}) to experimental load of the Cybulski et al were between 5.75% to 6.04%. Also, for the corrugated models, Table _{cr}) to experimental load of the Cybulski et al is reasonable [

In this study, it is aimed to compare the stress distributions on the corrugated and without corrugated by modeling in the ANSYS Workbench v16 program [

Boundary conditions for with and without corrugated models

One of the most important steps in finite-element (FE) analysis is the creation of mesh structure. The sweep, automatically generated, tetrahedrons and hex-dominant are meshing method in ANSYS Workbench program. The sweep method cannot be used in plate or concrete models. The non-sweep able bodies force the sweep method controlling. The automatically generated, tetrahedrons and hex-dominant method meshing compare their created nodes and elements for the same sizing [

Numbers of nodes and elements for corrugated model

Mesh Type | Number of nodes | Number of Elements |
---|---|---|

Automatically generated | 27159 | 7852 |

Tetrahedrons | 21956 | 6149 |

Hex-dominant | 37652 | 9874 |

Therefore, tetrahedron meshing with 10-node (every node of this volume has three degrees of freedom) selected for solving FE models. Mesh sizing is important for accurate stress value. For this purpose, selected meshing type, the tetrahedron mesh divides various sizing mesh starting with 10 mm. When the stress and displacement values are stable, this mesh sizing can be applicable for FE analysis. Fig.

Mesh sizing for corrugated model

Furthermore, Fig.

Mesh and Load of the models

A post-buckling analysis of a geometrically perfect structure may exhibit a sharp bifurcation at the buckling load, which may be missed in the Riks Method [

Figs. _{u}) / the maximum loads of FE models (P_{m}) for uncorrugated, and the corrugated ones are changed between 0.95 and 1.38. The average ratios for the experimental maximum displacements / the maximum displacements of FE models for uncorrugated and the corrugated ones are changed between 0.35 and 2.42. The uncorrugated member values were close for the experimental and numerical ones, unlike for the corrugated ones.

Load-displacement for the uncorrugated finite-element models

Load-displacement for the corrugated finite-element models

Comparison of maximum load and displacement of the models

Model | Max.load | Max. Displacement |
Max.load |
Max. Displacement |
---|---|---|---|---|

EX1 and FE1 |
3.4345 | 262.95 | 3.60 | 744 |

EX2 and FE2 |
14.1925 | 61.80 | 10.30 | 25.5 |

uncorrugated

corrugated

Figure

Maximum shear strain by FE for the with and without corrugated models

In this research, an experimental study was carried out to determine the load-strain and load-displacement curves representing the behavior of steel plate sections with k-span (super span model 600). Thus, the aim of the study was to analyse the influence of the corrugation on the behavior of cold formed steel members in the structure roofs. The key findings and observations are presented as follows:

The first buckling load of the member perpendicular to the load direction (orthogonal to horizontal load) is 1.59 times greater than the member perpendicular to the load (perpendicular to the load without vertical folding). Furthermore, the load carrying capacity of the member perpendicular to the load direction (orthogonal to horizontal load) is 4.13 times greater than the member perpendicular to the load (perpendicular to the load without vertical folding).

Comparison of the first buckling load (P_{cr}), and maximum load (P_{u}) of experimental model shows that, after the first buckling load (P_{cr}) of the models, they resisted the models themselves. They entered the stage of post-buckling. A fading effect is about 33.03% and 75.56% for the uncorrugated and corrugated models, respectively.

The analytical load of EC3 is greater than experimental first buckling load (P_{cr}) and experimental maximum load (P_{u}). On the other hand, if anyone wants to get the first buckling load (P_{cr}) and the maximum load (P_{u}) times according to theoretical formulas, it must multiply the coefficients to obtain the first buckling load (P_{cr}) and the maximum load (P_{u}).

The average ratios for the experimental maximum loads (P_{u}) / the maximum loads of FE models (P_{m}) for uncorrugated, and the corrugated ones are changed between 0.95 and 1.38. The average ratios for the experimental maximum displacements / the maximum displacements of FE models for uncorrugated and the corrugated ones are changed between 0.35 and 2.42. The uncorrugated member values were close to each other for the experimental and numerical ones, unlike for the corrugated ones.

The numerical models are consistent and show local and distortional buckling in the models. The failures of the numerical models are same as the failure of the experimental ones.

making the horizontal corrugated element both increased the load carrying capacity and increased the displacement capacity. In addition, the two tensile scales showed the same behavior both horizontally and vertically, but at the same time they transitioned to plastic regions from the elastic region. In addition, the tension was more than two times more than shear behavior in serrated steel plate section. These are faults that occur in the way of making the biggest annoyance in the buildings. All the experiments showed torsional behavior, and the shape distortions were V-shaped.

This study was supported by Gençler Metal Steel Company (Erzurum, Turkey).