neural network modeling for rotational capacity of … · benjamin w. schafer (2005) [6]. the...
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http://www.iaeme.com/IJCIET/index.asp 362 [email protected]
International Journal of Civil Engineering and Technology (IJCIET)
Volume 8, Issue 12, December 2017, pp. 362–372, Article ID: IJCIET_08_12_043
Available online at http://http://www.iaeme.com/ijciet/issues.asp?JType=IJCIET&VType=8&IType=12
ISSN Print: 0976-6308 and ISSN Online: 0976-6316
© IAEME Publication Scopus Indexed
NEURAL NETWORK MODELING FOR
ROTATIONAL CAPACITY OF COLD-FORMED
PURLIN STEEL SECTIONS
Dr. Ahmed Ajel Ali
Department of Structures and Water Resources, Faculty of Engineering,
Kufa University, Najaf, Iraq
ABSTRACT
The possibility of consuming artificial neural networks (ANN) using Matlab
software to calculate the rotational capacity of steel cold-formed C- and Z-section
purlins. Rotational capacity is a significant phenomenon as in the situation of steel
purlins which are extensively used in roofing wide-ranging buildings. The complex
conducts of such members make the conventional design approaches not satisfactory
from a reliability standpoint.
The main aim of this paper was to give a quick and precise technique for
estimating local buckling capacity of C-and Z-section purlin. Good agreement was
attained concerning (ANN) technics outcomes and data from literature.
Trained neural network develops easy to-utilize method for calculating yielding
and ultimate moment's capacity of C-and Z-section. Broad parametric investigations
were additionally performed and introduced graphically to analyse the impact of
geometric and mechanical properties on rotational capacity. It was found that the
proposed (ANN) based technics is practical in predicting both the yield and buckling
rotational strength of cold-formed purlin steel sections.
Key words: Rotational capacity, Purlin, cold-formed steel, Neural Networks,
Analytical methods.
Cite this Article: Dr. Ahmed Ajel Ali, Neural Network Modeling for Rotational
Capacity of Cold-Formed Purlin Steel Sections. International Journal of Civil
Engineering and Technology, 8(12), 2017, pp. 362-372.
http://www.iaeme.com/IJCIET/issues.asp?JType=IJCIET&VType=8&IType=12
1. INTRODUCTION
There are fundamentally two sorts of basic steel members in construction development: cold-
formed and hot-rolled members. The common hot-rolled shape members are molded at lifted
temperatures whereas the cold-formed members are molded at normal temperatures. Members
of cold-formed sections were shapes regularly fabricated from steel plate, sheet metal or strip
material. The assembling procedure includes framing the material by either press-braking or
cold move shaping toward accomplish fancied form.
Neural Network Modeling for Rotational Capacity of Cold-Formed Purlin Steel Sections
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For cold-formed members, the width-to-thickness ratios of distinct elements are frequently
large. These thin elements could buckle locally at a stress level lower than the yield stress of
the material when they are subject to compression in flexural bending. Therefore, for the
design of such thin-walled sections, for example, Z-and C-purlins which may experience
flexural-torsional clasping due to their low torsional solidness, if not appropriately braced,
local buckling and post buckling strength have regularly been the actual design
contemplations. From the steel designers view point the cold-formed steel members are most
preferable to use mainly on non-load bearing partition, curved walls, etc. due to its flexural
strength and good appearance. Nonetheless, this adaptability, depend on design guidelines
that dealt with cold-formed steel , creates the determination of the best economical section for
a specific request troublesome, together in optimization terms, and as far practical design.
Choosing the best section needs various emphases including investigation of a few
conceivable profiles and aspect ratios. This procedure turns out to be restrictively costly
because of the measure of time essential on behalf of meeting to a most favorable scheme.
The paper discovers the opportunity of utilizing artificial neural network to solve some of
these design issues.
2. NEURAL NETWORK MODELLING BACKGROUND
The method that organic sensory schemes (ex. the human minds) used as a design handling
for data is the main principal of the Artificial Neural Network (ANN).
The ANNs, like any organic brain learn by practice (data collection and expert), such as,
ordering information, acknowledgment design or even remembering by using learning
process. The data preparing is the major part of this pattern and it is the unique assembly of
the framework. It is made of extensive correlated processing elements (neurones) that are
solving problems. Learning in the frameworks depends on the relations and variations that
happen among the neurones.
The use of neural schemes began from several decades. McCulloch-Pitts (1943) [1]
depicted paired limit neurons officially in 1940's. In 1958, Rosenblatt [2] promoted the
utilization of perceptron, a particular kind of neurons, such as exceptionally adaptable
instruments used for playing out an assortment of errands. The neural systems rise was
stopped afterward Minsky and Papert (1969) [3] distributed a book dealt with abilities of
perceptron's, so scientifically verified that it can't generally ensure in particular. That outcome
immediately summed up near every single neural system, while it really connected just to a
particular kind of perceptron's, prompting the being of neural systems neglected as a machine
learning technique.
In the last two decade there was a great improvement in computing hardware that
permitting us to train precise huge and compound networks in practical period. The neural
network has made an exciting comeback since many investigations become much more
active. An inclusive explanation of this kind of neural networks is afar the latitude of this
paper and can be found in numerous literatures e.g., [4- 5].
3. DATABASE INFORMATION
Data was selected carefully from the test information incorporated by Cheng Yu and
Benjamin W. Schafer (2005) [6]. The database containing of 50 cold-formed tested steel
purlins. The experimental local buckling results are given in Table 1 .The elastic buckling
moments was computed via the same researchers above numerically by using finite element
analysis.
Dr. Ahmed Ajel Ali
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Table I compresses the parameters scope of the chosen experiments.
Figure 1 Descriptions of purlin measurements for C and Z-section [6]
Table 1 Input Parameters Range.
Parameter Range
Min. Max.
h,in 8 12.02
bc,in 1.79 3.52
dc,in 0.49 0.98
θc, deg 45.4 89.3
bt,in 1.96 3.54
dt,in 0.42 1.0
θt, deg 44.2 94.8
t,in 0.047 0.118
fy,ksi 32 68.8
Table 2 outlines the properties of the chosen database[6].
Table 2 Database Information's [6]
G. Specimen
t
(in.)
bt
(in.)
Dt
(in.)
Bc
(in.)
dc
(in.)
h
(in.)
Rhc
(in.)
rdt
(in.)
rdc
(in.)
rht
(in.)
Өc
(deg)
Өt
(deg)
Fy
(ksi)
Mtest
(kip-in)
My (kip-in)
1
8.5Z120,3 0.118 2.46 0.99 2.58 0.96 8.44 0.36 0.35 0.36 0.35 47.2 48.90 61.3 280 268
8.5Z120,2 0.118 2.46 1.00 2.59 0.96 8.47 0.36 0.34 0.36 0.34 47.8 48.90 60.1 280 264
8.5Z105,2 0.104 2.36 0.95 2.66 0.95 8.48 0.32 0.34 0.32 0.34 50.5 48.70 68.8 268 270
8.5Z105,1 0.105 2.36 0.91 2.69 0.97 8.42 0.31 0.34 0.31 0.34 50.7 48.70 66.8 268 264
8.5Z092,4 0.090 2.41 0.96 2.61 0.93 8.41 0.29 0.31 0.29 0.31 53.00 50.80 57.3 181 192
8.5Z092,2 0.088 2.40 0.95 2.61 0.92 8.43 0.28 0.31 0.28 0.31 51.80 50.40 57.0 181 189
8.5Z082,1 0.080 2.36 0.97 2.5 0.95 8.46 0.28 0.30 0.28 0.30 49.00 50.30 58.4 162 174
8.5Z082,2 0.080 2.40 0.95 2.51 0.95 8.45 0.28 0.30 0.28 0.30 47.90 52.40 58.1 162 174
8.5Z073,6 0.072 2.40 0.94 2.52 0.92 8.50 0.28 0.30 0.28 0.30 49.60 50.90 54.0 121 146
8.5Z073,5 0.072 2.40 0.94 2.52 0.92 8.50 0.28 0.30 0.28 0.30 49.60 50.90 55.6 121 152
8.5Z073,4 0.071 2.41 0.92 2.53 0.93 8.51 0.28 0.29 0.28 0.29 49.60 50.30 56.1 134 151
8.5Z073,3 0.072 2.38 0.96 2.53 0.91 8.50 0.28 0.30 0.28 0.30 50.10 51.00 55.6 134 150
8.5Z073,2 0.071 2.41 0.92 2.54 0.93 8.50 0.28 0.30 0.28 0.30 50.20 51.00 55.7 123 150
8.5Z073,1 0.072 2.41 0.95 2.5 0.92 8.49 0.28 0.30 0.28 0.30 48.40 51.20 54.8 123 147
8.5Z065,3 0.064 2.43 0.79 2.42 0.83 8.47 0.27 0.28 0.27 0.28 47.30 47.30 53.5 96 125
8.5Z065,1 0.064 2.43 0.84 2.44 0.76 8.47 0.28 0.27 0.28 0.27 47.40 47.10 53.1 96 123
8.5Z059,4 0.059 2.35 0.72 2.5 0.77 8.50 0.28 0.28 0.28 0.28 50.90 48.90 58.6 100 126
8.5Z059,3 0.059 2.22 0.69 2.44 0.78 8.50 0.28 0.28 0.28 0.28 50.20 50.40 58.5 100 125
8.5Z059,2 0.059 2.33 0.70 2.51 0.78 8.49 0.28 0.28 0.28 0.28 50.60 50.20 59.1 99 127
8.5Z059,1 0.059 2.33 0.71 2.51 0.78 8.50 0.28 0.28 0.28 0.28 51.20 49.40 58.9 99 127
2
8C097,2 0.098 2.08 0.52 2.12 0.57 8.04 0.30 0.30 0.28 0.28 85.60 85.70 59.9 172 166
8C097,3 0.094 2.08 0.54 2.09 0.56 8.03 0.30 0.29 0.28 0.28 84.00 88.20 59.6 172 157
8C068,5 0.075 2.04 0.53 2.03 0.52 8.03 0.28 0.24 0.25 0.24 83.20 87.00 48.6 104 102
Neural Network Modeling for Rotational Capacity of Cold-Formed Purlin Steel Sections
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G. Specimen
t
(in.)
bt
(in.)
Dt
(in.)
Bc
(in.)
dc
(in.)
h
(in.)
Rhc
(in.)
rdt
(in.)
rdc
(in.)
rht
(in.)
Өc
(deg)
Өt
(deg)
Fy
(ksi)
Mtest
(kip-in)
My (kip-in)
8C068,4 0.077 2.04 0.54 2.05 0.52 8.01 0.27 0.27 0.26 0.24 84.00 87.60 53.1 104 114
8C068,2 0.075 2.04 0.53 2.04 0.52 8.02 0.28 0.26 0.25 0.24 83.40 87.60 51.7 98 109
8C068,1 0.075 2.05 0.53 2.03 0.53 8.03 0.30 0.26 0.26 0.25 83.10 88.10 51.4 98 108
8C054,1 0.055 2.07 0.50 2.04 0.52 8.00 0.22 0.23 0.23 0.23 88.90 84.70 40 56 62
8C054,8 0.054 1.96 0.48 2.02 0.58 8.08 0.22 0.23 0.20 0.22 88.10 82.30 40.3 56 63
8C043,5 0.049 1.98 0.53 2.02 0.53 8.04 0.18 0.20 0.20 0.21 88.80 87.30 44.9 51 64
8C043,6 0.049 2.00 0.46 2.01 0.53 8.06 0.19 0.20 0.20 0.22 88.90 87.00 45.0 51 63
8C043,3 0.047 2.01 0.53 2.02 0.54 8.04 0.19 0.19 0.19 0.19 89.30 87.50 46.0 48 63
8C043,1 0.047 1.98 0.54 2.02 0.54 8.03 0.19 0.19 0.19 0.29 89.00 85.80 45.7 48 62
3
12C068,9 0.065 2.00 0.55 1.92 0.53 12.002 0.28 0.28 0.27 0.30 82.00 85.30 35.1 104 113
12C068,5 0.065 2.06 0.53 1.79 0.55 12.00 0.27 0.27 0.27 0.22 85.90 94.80 35.0 104 110
12C068,3 0.0671
1.99 0.56 1.96 0.59 11.97 0.26 0.27 0.27 0.27 82.50 77.40 56.6 137 190
12C068,4 0.067 2.00 0.52 2.01 0.52 12.02 0.26 0.27 0.27 0.26 80.60 83.30 57.3 137 192
10C068,2 0.057 1.98 0.52 1.93 0.50 10.08 0.27 0.25 0.25 0.27 83.20 83.30 33.6 70 73
10C068,1 0.057 1.97 0.54 2.04 0.55 10.03 0.27 0.25 0.26 0.28 80.70 81.90 34.2 70 76
6C054,2 0.061 2.00 0.52 2.00 0.56 6.04 0.21 0.25 0.24 0.26 85.70 90.00 36.1 45 42
6C054,1 0.061 2.05 0.52 2.01 0.56 6.03 0.22 0.24 0.25 0.25 86.50 90.50 37.0 45 43
4C054,1 0.055 2.02 0.55 1.99 0.55 3.95 0.24 0.24 0.24 0.23 79.20 77.40 45.0 28 27
4C054,2 0.056 1.96 0.55 1.95 0.50 3.96 0.22 0.25 0.27 0.25 74.20 74.80 44.7 28 27
3.62C054,1 0.055 2.00 0.42 1.97 0.49 3.65 0.23 0.25 0.26 0.26 77.10 88.10 32.8 20 17
3.62C054,2 0.055 1.97 0.44 1.99 0.51 3.67 0.24 0.26 0.25 0.26 79.80 79.80 32.0 20 17
4
11.5Z092,1 0.102 3.51 0.96 3.33 0.96 11.41 0.25 0.27 0.27 0.27 50.10 49.50 61.0 352 414
11.5Z092,2 0.103 3.54 0.89 3.33 0.98 11.34 0.28 0.28 0.27 0.28 48.30 48.10 60.4 352 409
11.5Z082-2 0.083 3.45 0.87 3.50 0.88 11.45 0.31 0.35 0.31 0.35 50.30 52.20 61.5 274 345
11.5Z082,1 0.083 3.43 0.88 3.49 0.9 11.47 0.32 0.35 0.32 0.35 50.60 51.00 60.4 274 341
11.5Z073,2 0.070 3.35 0.83 3.51 0.87 11.39 0.27 0.28 0.28 0.27 46.00 44.80 65.4 194 311
11.5Z073,1 0.069 3.40 0.90 3.52 0.95 11.35 0.27 0.07 0.11 0.27 45.40 44.20 66.8 194 315
4. NEURAL NETWORK DESIGN AND TRAINING
The utilization of the ANN models, first of all, the whole data was irregularly separated into
training and testing groups. When accessible data have been separated to subgroups, the
scaling process to the input and output variables was achieved by scaling them over the
vicinity of 0.0 and 1.0 [7], to take out their measurement and to guarantee that all factors get
equivalent consideration amid preparing.[8]
Ten of the selected data was used as monitoring group for the training process progress,
all training of the network [9] comprised of one pass over the entire 50 training data groups.
[9] In building the neural network model, the network topology is developed by
identifying the number of hidden layers and the number of neurons in each. Network learns
by contrasting its yield for each pattern and an objective chose output for that pattern, after
that the way toward learning the mistake and stimulating a mistake function in reverse
through the neural network was finished.
The pattern of the network consisted of thirteen input values and two outputs; the
justification for that was to consider the criticalness of geometry and materials data on the
cold-formed member's strength in bending.
The used network has two hidden layers with fifteen nodes each, and with two nodes
giving yielding and failure moment capacity of section in the output layer.
Figure (3) was demonstrated the minimum error that dispensed by neural network form as
shown in figure (2). The settled topology and featured are presented in Table 3 .
Dr. Ahmed Ajel Ali
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Figure 2 Neural Network Architecture
Table 3 Network used Topology
Number of epochs required
for training 5000
Performance function in
terms of MSE 0.01
Architecture 13-15-15-2
Learning Algorithm Learn gdm
Activation Function Logsig- Logsig- purelin
Training algorithm used Back probation algorithm
5. RESULTS AND DISCUSSION
Results of the artificial neural network prediction and the investigational data are outlined in
figure 3 for the picking training and testing data.
The predicted ANN results precision due to rotational capacity of cold-formed steel
members in bending presented in Figures (7-10) to the designated investigational groups (1,
2, 3, 4), the comparison indicates that the results from the ANN model and the data from the
experimental results are in good agreements.
Figure 11 shows the rotational cold-formed strength in bending for different cross
sections.
Figure 3 Training outputs regression
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6. VERIFICATIONS
The experimental records afford an adjustment opportunity for the ANN modeling and hers
numerous conventions. ANN models similarly offer a complementary implement to explore
the cold formed steel members buckling mechanism through numerous outlines. In this paper,
the customary ANN demonstrating stood substantiated by the data-base described in section 4
consequently a selected specimens (excluding similar specimens) from the four group of the
data-base was utilized to show validation of the established ANN graphically.
The essential attention in studying was the web slenderness (h/t) that achieved by
changing the section thickness t, while stock h, b, d unceasing or fluctuating h whereas
stocking b, d and t constant for both the selected Cee and Zee sections.
Figure 5 Data-base and predicted
moment gradient ratios vs. h/t ratios for
Cee Section from group 2.
Figure 4 Data-base and predicted
moment gradient ratios vs. h/t ratios
for Zee Section from group 1.
Figure 7 Data-base and predicted
moment gradient ratios vs. h/t ratios
for Zee Section from group 4.
Figure 6 Data-base and predicted
moment gradient ratios vs. h/t ratios
for Cee Section from group 3.
Dr. Ahmed Ajel Ali
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Moment gradient influence on local buckling of Cold-formed shape was so significant,
relatively since this topic has not been considered in details. Auxiliary, as moment gradient
could substantially effect of CFS buckling ability. Therefore in this paper all the results are
presented with respect to moment gradient.
Figures 4-7 offered a comparison between the ANN model results and the data-base
results for the selected specimens from (1, 2, 3, and 4) test group.
The assessment between the numerical NN model and the data-base results includes the
moment gradient vs. the web height slenderness ration. From figures, it is shown that the
developed NN model can give a close prediction to the elastic and buckling moment
resistance for the CFS section for both Cee and Zee sections.
7. PARAMETRIC STUDY
The moment capacity cold-formed steel members in bending depend mainly on the
mechanical properties of the materials and the geometry of section.
Efficacious neural network verification model, allowance to revision the utilization of more
prominent assortment of cold-formed sections (not tested tentatively) conceivable. The data
acquired from both the data-base and the prolonged neural techniques was helpful for
investigating the local buckling capacity on a board range of cold-formed steel C- and Z-
section beams.
The main concern in studying was the ratios of web slenderness (h/t) and flange
slenderness (b/t) to provide systematic variation in sections, which was achieved by variation
t and h while holding b constant.
Also by varying the steel yield strength while holding section geometry constant also
studied to accomplish materials strength effect.
However, in experimental work the commercially available sections were limited, while
shapes up to thickness of 1/2 and even 3/4 in. can be found, cold-formed steel construction is
usually restricted to thickness ranging from 30 gage (0.012 in.) to 4 (0.224 in.), the manner
wherein the (h/t) diversity might be completed was limited by the of cross sections
availability.
Figure 9 Predicted moment gradient ratio,
M/My vs. web slenderness ratios (h/t)
ratio for Cee Section from group 2.
Figure 8 Predicted moment gradient
ratio, M/My vs. web slenderness ratios
(h/t) ratios for Zee Section from group 1.
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Fig.8 and 9 shows the relationship between critical moment gradient, M/My, and web
slenderness ratio (h/t) for increasing height for C-section and Z-section. The moment gradient
is non-dimensional with respect to elastic moment capacity, My. the study accomplished
through the adoption of specimen (8C097-2) from group 2 and specimen (8.5Z120-3) from
group 1, with a web height change within the limits (6 - 12 in) and section thickness change
within the (0.06 – 0.11 in ) , it can be noticed that by increasing section web depth there was
affordability increasing in buckling moment gradient for both Cee and Zee sections, in other
word it is clear that the buckling moment capacity is proportional to the section depth and has
the most significant effect on the buckling moment capacity of the section. The buckling
moment gradient significantly increased for both C and Z-section beyond the ratio of 0.7.
From figure 9, It was also can be seen that there is a change in behavior from stocky
(M/My ) to slender for section with (h=6 & 8 in) to be slender with the increase of Z-
section web height. The thicker specimens have high local buckling moment capacity then the
member strength controlled by lateral-torsional capacity.
In figure (10,11) presented the relationship between the buckling to the yielding moments
with the flange slenderness ratio (b/t), it was also don by adopting the same sections
properties and also by changing the web height of the members cross section for both of the
chosen Cee and Zee section.
The parametric conducted that results have shown a reduction in moment gradient
capacity exists with increase in the web slenderness ratio, the slenderness influence on
gradient was of little effect beyond the slenderness ratio about (35) regardless of member
height of the section. It is hypothesized that increased flange and web deformations decrease
moment capacity.
Figure 10 Predicted moment gradient
ratio, M/My vs. flange slenderness
ratios (b/t) ratios for Zee Section from
group 1.
Figure 11 Predicted moment gradient
ratio, M/My vs. flange slenderness
ratios (b/t) ratios for Cee Section from
group 2.
Dr. Ahmed Ajel Ali
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Figure 12 Variation yield strength on moment gradient, M/My, for C purlin section with h=6 in.
Figure 13 Variation yield strength effect on moment gradient, M/My, for C purlin section with h=8 in.
The Z-section cold formed steel beams have less variation in material properties in the
gathered experimental data, the steel yield stress are between (60 to 70 ksi). On in actuality,
the C-section have extraordinarily differing material properties, whereas steel yield stress
recorded from (20 to 66.8 ksi), so it is adopted to study the effect of materials property on the
buckling moment capacity of the cold formed steel purlin.
For the C-section section (8C097-2) from group 1, four levels of steel yield stress was
used (30, 40, 50, 60 psi) hence these values are compatible with most of that produced
industry standard sections. The study showed the relationship between the proportion of
buckling moment gradient to the web slenderness ratio and to the flange slenderness (b/t)
respectively with a web height change within the limits (6 - 12 in).
From Figs 12 to 15 it is clear that the steel yield strength has almost a constant effect on
the predicted buckling moment capacity of C-section that the four cases are approximately
parallel to each other, higher yield strength steel also increase the potential yielding moment
capacity of the section, also the same trend for the both web slenderness ratio and to the
flange slenderness was observed due to the yield strength change.
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
40 60 80 100 120 140
M/M
y
h/t
Fy=60 ksi
Fy= 50 ksi
Fy= 40 ksi
Fy=30 ksi
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
20 25 30 35 40 45
M/M
y
b/t
Fy=60 ksi
Fy= 50 ksi
Fy= 40 ksi
Fy=30 ksi
0
0.2
0.4
0.6
0.8
1
1.2
1.4
60 110 160 210
M/M
y
h/t
Fy=60 ksi
Fy= 50 ksi
Fy= 40 ksi
Fy=30 ksi
0
0.2
0.4
0.6
0.8
1
1.2
20 25 30 35 40 45
M/M
y
b/t
Fy=60 ksi
Fy= 50 ksi
Fy= 40 ksi
Fy=30 ksi
Neural Network Modeling for Rotational Capacity of Cold-Formed Purlin Steel Sections
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Figure 14 Variation yield strength effect on moment gradient, M/My, for C purlin section with h=10 in.
8. CONCLUSIONS
The developed ANN model was tested and verified then extended to estimate rotational
capacity for the cold-formed sections with a wide geometric range for C- and Z-sections. The
ANN model also was used to yield a parametric study to illustrate the effect of steel yield
strength and the slenderness ratio of web and flange for C- and Z-sections.
The main conclusion to be drawn from the techniques used can be summarizing below:
1- Study the usage of ANN to calculate rotational moment capacity of cold-formed purlin
sections. The correlation, R, obtained using ANN models was about 0.99 in the calibration
and confirmation groups. Results from the ANN model results match well with the existing
structural information and investigational data.
Figure 15 Variation yield strength effect on moment gradient, M/My, for C purlin section with h=12 in.
2- The existing design methods for cold-formed steel sections are excessively difficult, a
substantial extent of this difficulty is owing to the requirement to compute elastic buckling
capacity by hand or with so complicated numerical methods. In this research, design methods
0
0.2
0.4
0.6
0.8
1
1.2
1.4
60 110 160 210
M/M
y
h/t
Fy=60 ksi
Fy= 50 ksi
Fy= 40 ksi
Fy=30 ksi
0
0.2
0.4
0.6
0.8
1
1.2
1.4
20 25 30 35 40 45
M/M
y
b/t
Fy=60 ksi
Fy= 50 ksi
Fy= 40 ksi
Fy=30 ksi
0
0.2
0.4
0.6
0.8
1
1.2
80 130 180 230
M/M
y
h/t
Fy=60 ksi
Fy= 50 ksi
Fy= 40 ksi
Fy=30 ksi
0
0.2
0.4
0.6
0.8
1
1.2
20 25 30 35 40 45
M/M
y
b/t
Fy=60 ksi
Fy= 50 ksi
Fy= 40 ksi
Fy=30 ksi
Dr. Ahmed Ajel Ali
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may be accomplished numerically with great consistency and simplicity by using the
developed ANN model.
3- The buckling moment capacity for the CFS section was increased by increasing section
web depth and there was affordability increasing in buckling moment gradient for both Cee
and Zee section, in other word it is clear that the buckling moment capacity is proportional to
the section depth and has the most significant effect on the buckling moment capacity of the
section.
4- The steel yield strength has almost a constant effect on the predicted buckling moment
capacity of CFS C-section, higher yield strength steel also increase the potential yielding
moment capacity of the section, also the same trend for the both web slenderness ratio and to
the flange slenderness was observed due to the yield strength change.
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