wind load design of hangar-type closed steel structures with … · 2017-05-29 · this study...
Post on 28-Mar-2020
3 Views
Preview:
TRANSCRIPT
TEM Journal. Volume 6, Issue 2, Pages 336-341, ISSN 2217-8309, DOI: 10.18421/TEM62-19, May 2017.
336 TEM Journal – Volume 6 / Number 2 / 2017
Wind Load Design of Hangar-Type Closed
Steel Structures with Different Roof Pitches
Using Abaqus CAE Software
Aybike Özyüksel Çiftçioğlu 1, Sadık Alper Yıldızel
1,
Mehmet Sinan Yildirim 1, Erkan Doğan
1
1Manisa Celal Bayar University,Engineering Faculty, Manisa, Turkey
Abstract – Structures convert the kinetic energy
available in the air into potential energy which is in the
form of pressure and suction forces reducing or fully
stopping its motion. The potential impact of the wind
depends on the geometric properties and pertinacity of
a building, the angle of the wind flow, its strength and
velocity. Design gains importance for tall buildings
against the impact of the resonance along with the
force based on pressure. Relevant calculations are
made in Turkey based on the TS 498 Wind Load
Velocity Criterion and this standard is currently being
updated.
This study develops the wind load design of hangar-
type closed steel structures with different roof pitches
using Abaqus CAE software.
Keywords – Steel, steel structures, wind, wind load.
1. Introduction
The use of iron and steel goes back to 5,000 years,
yet the area of use has been limited only to weaponry
and gears until the beginning of the 18th century [1].
With the production of bloom introduced in England
by 1779, cast iron was used in the bridge building
projects as a structural element for the first time
(Coalbrookdale Bridge, Figure 1) [2].
DOI: 10.18421/TEM62-19 https://dx.doi.org/10.18421/TEM62-19 Corresponding author: Sadık Alper Yıldızel, Manisa Celal Bayar University, Engineering Faculty, Manisa, Turkey Email: sadikalper.yildizel@cbu.edu.tr
© 2017 Aybike Özyüksel Çiftçioğlu et al; published by UIKTEN. This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License. The article is published with Open Access at www.temjournal.com
Figure 1. Coalbrookdale Bridge, UK
With the development of Bessemer, Siemens –
Martin and Thomas methods, cast steel production
was started and cast steel has been the most
commonly used steel product since the beginning of
the 19th century per the literature. As steel structures
are built rather fast, they had been more frequently
preferred in the aftermath of the WWI and steel has
become the commonly used structural element since
the WWII [3,4]. Design criteria has been updated per
the developments and shaped the ones we use today.
The loads to be considered for steel structures can be
classified under Dead Load, Live Load, Horizontal
Load, and others (Table 1) [5].
Table 1. Load Types for Steel Construction Design
Dead Load Weight of floor systems, beam systems,
wall systems, etc.
Live Load Furniture loads, human loads, etc.
Horizontal
Load
Earthquake load, wind load, fluid load,
etc.
Other Loads Warping and swelling loads, explosion
load, etc.
One of the load types involved in steel construction
design, the wind load is commonly recognized as a
TEM Journal. Volume 6, Issue 2, Pages 336-341, ISSN 2217-8309, DOI: 10.18421/TEM62-19, May 2017.
TEM Journal – Volume 6 / Number 2 / 2017. 337
horizontal load. It might be considered as a static
load if the structure in question does not yield
significant values for this kind of a load. Wind results
in pressure in the direction of the impact surface
while resulting in suction force on the opposite
direction. The velocity of the wind increases to a
point due to the height of the structure. Wind load
must be taken into consideration as the highest value
on each side and it depends on the geometrical
structure of the building [6]. Wind loads in Turkey
are calculated using the TS 498 standard [5].
However, as the structures such as bridges, cranes,
tall flues, beacons, etc., are governed by specific
regulations, it is not possible to make calculations
using the TS 498 standard. Per this regulation, the
resultant of the wind load on the roof is calculated
using the equation (1).
W = Cf x q x A (1) [4]
In this equation, “Cf” is the aerodynamic load
coefficient, “q” is the suction force, and A is the
surface area in question. Table 2. shows the suction
and velocity of the wind per the height of the roof. It
is important to have the support of the Regional
Directorate of Meteorology to minimize the
calculation errors in the determination of q value for
regions exposed to higher wind velocity.
Table 2. Suction and Wind Speed Values Based on Height
Above Ground Level [TS 498 Chart-5]
Height Above
Ground Level (m)
Wind Speed
(km/hour)
q
(kN/m²)
0-8 28 0,5
8-20 36 0,8
21-100 42 1,1
> 100 46 1,3
It is important to take heed of wind loads which will
be increased due to icing of the surfaces for steel
construction projects which involves slim type
structural steel [7].
Another important aspect of the wind load
calculations is the vortex load resulting from the
vortex passage [8]. The air flow caused by the wind
results in vortexes while passing through the sides of
a building (Figure 2.). As vortexes are variable in
their nature, the resulting loads are also variable and
have an impact perpendicular to the direction of the
wind flow. Nevertheless, as these loads impact a very
specific and narrow area, they can be accounted to as
sinusoidal load [9,10].
Figure 2. Creation of Vortex Load [11]
2. Modelling
Wind speeds of 28m/s, 36 m/s, 42 m/s, and 46
m/s were examined on steel structures with 30o and
45o roof pitches using the Abaqus CAE software
[12]. The height above ground level was taken 7m,
20m, 100m and 105m for each trial. The winds with
wind speed of 28m/s, 36 m/s, 42 m/s, and 46 m/s
were converted into suction value, q (kN/m²), using
the “q=V²/ 1600” equation. The results obtained are
converted into distributed load using the equations in
the Figure 3. and the results are given in Table 3.
Figure 3. TS 498 11/3 Figure-1
Table 3. q Values used in the Abaqus CAE software
h
(m)
q1
(kN/m²)
q2 (30°)
(kN/m²)
q2 (45°)
(kN/m²)
q3
(kN/m²)
q4
(kN/m²)
8 0.392 0.098 0.22 -0.196 -0.196
20 0.648 0.162 0.3629 -0.324 -0.324
100 0.882 0.2205 0.494 -0.441 -0.441
105 1.058 0.2645 0.5924 -0.529 -0.529
The reason behind the height above ground level
values was that they make it possible for a reliable
comparison with the stress values available in the TS
TEM Journal. Volume 6, Issue 2, Pages 336-341, ISSN 2217-8309, DOI: 10.18421/TEM62-19, May 2017.
338 TEM Journal – Volume 6 / Number 2 / 2017
498 standard (Table 2.). Results obtained from the
analysis were then compared with the TS 498
standard. The highest q1 stress was taken as a basis
because of this comparison.
2.1. Analysis A (the hangar with 30° roof pitch and
8m height above ground level):
Based on the q1 value which is the highest stress
value obtained from the hangar modelled to have 30°
roof pitch, the value obtained was 0,275 kN/m²
(Figure 4.).
Figure 4. The structure with 30° roof pitch and 8m height
above ground level
Figure 5. shows the change in the stress over time.
Figure 5. Analysis A, Graph of Stress vs. Time
2.2. Analysis B (the structure with 45° roof pitch
and 8m height above ground level):
Based on the q1 value which is the highest stress
value obtained from the hangar modelled to have 45°
roof pitch, the value obtained was 0.303 kN/m²
(Figure 6.).
Figure 6. The structure with 45° roof pitch and 8m height
above ground level
Figure 7. shows the change in the stress over time.
Figure 7. Analysis B, Graph of Stress vs. Time
2.3. Analysis C (the structure with 30° roof pitch
and 20 m height above ground level):
Based on the q1 value which is the highest stress
value obtained from the hangar modelled to have 30°
roof pitch, the value obtained was 0.275 kN/m²
(Figure 8.).
Figure 8. The structure with 30° roof pitch and 20 m
height above ground level
TEM Journal. Volume 6, Issue 2, Pages 336-341, ISSN 2217-8309, DOI: 10.18421/TEM62-19, May 2017.
TEM Journal – Volume 6 / Number 2 / 2017. 339
Figure 9. shows the change in the stress over time.
Figure 9. Analysis C, Graph of Stress vs. Time
2.4. Analysis D (the structure with 45° roof pitch
and 20m height above ground level):
Based on the q1 value which is the highest stress
value obtained from the hangar modelled to have 45°
roof pitch, the value obtained was 0.323 kN/m²
(Figure 10.).
Figure 10. The structure with 45° roof pitch and 20 m
height above ground level
Figure 11. shows the change in the stress over time.
Figure 11. Analysis C, Graph of Stress vs. Time
2.5. Analysis E (the structure with 30° roof pitch
and 100 m height above ground level):
Based on the q1 value which is the highest stress
value obtained from the hangar modelled to have 45°
roof pitch, the value obtained was 0.276 kN/m²
(Figure 12.).
Figure 12. Analysis C, Graph of Stress vs. Time
Figure 13. shows the change in the stress over time.
Figure 13. The structure with 30° roof pitch and 100 m
height above ground level
2.6. Analysis E (the structure with 30° roof pitch
and 100 m height above ground level):
Based on the q1 value which is the highest stress
value obtained from the hangar modelled to have 45°
roof pitch, the value obtained was 0.386 kN/m²
(Figure 14.).
TEM Journal. Volume 6, Issue 2, Pages 336-341, ISSN 2217-8309, DOI: 10.18421/TEM62-19, May 2017.
340 TEM Journal – Volume 6 / Number 2 / 2017
Figure 14. The structure with 45° roof pitch and 100 m
height above ground level
Figure 15. shows the change in the stress over time.
Figure 15. The structure with 45° roof pitch and 100 m
height above ground level
2.7. Analysis G (the structure with 30° roof pitch
and 105m height above ground level):
Based on the q1 value which is the highest stress
value obtained from the hangar modelled to have 30°
roof pitch, the value obtained was 0.284 kN/m²
(Figure 16.).
Figure 16. The structure with 30° roof pitch and 105 m
height above ground level
Figure 17. shows the change in the stress over time.
Figure 17. The structure with 30° roof pitch and 105 m
height above ground level
2.8. Analysis F (the structure with 45° roof pitch
and 105 m height above ground level):
Based on the q1 value which is the highest stress
value obtained from the hangar modelled to have 30°
roof pitch, the value obtained was 0.436 kN/m²
(Figure 18.).
Figure 18. The structure with 45° roof pitch and 105 m
height above ground level
Figure 19. shows the change in the stress over time.
Figure 19. The structure with 45° roof pitch and 105 m
height above ground level
TEM Journal. Volume 6, Issue 2, Pages 336-341, ISSN 2217-8309, DOI: 10.18421/TEM62-19, May 2017.
TEM Journal – Volume 6 / Number 2 / 2017. 341
3. Conclusion
The following findings were obtained in the light of the outcomes of the analysis conducted:
The stress value results obtained from the Abaqus
CAE software are significantly different from the
ones obtained using the TS 498 standard.
Analysis results reveal the necessity to update the
relevant standards immediately.
It is possible to implement corrections updating the
standard in question to eliminate this difference while
saving from materials in a great extent using these
updated calculation methods.
The necessity of double checking the calculations
made in accordance with this standard against
Abaqus CAE and other similar programs for each
structure is obvious.
References
[1]. Schubert, H. R. (1957). History of the British iron &
steel industry.
[2]. Cossons, N., & Trinder, B. S. (2002). The iron bridge:
Symbol of the Industrial Revolution. Phillimore &
Company.
[3]. Chen, W. F., & Duan, L. (2014). Bridge Engineering
Handbook: Superstructure Design. CRC press.
[4]. Holmes, J. D. (2015). Wind loading of structures.
CRC press.
[5]. Turkish Standards (1997). “Calculation Values for the
Loads to be Considered in the Design of Structural
Elements (TS 498 – 1997)”, Turkish Standards Institute,
Ankara
[6]. Turkstra, C. J., & Madsen, H. O. (1980). Load
combinations in codified structural design. Journal of the
Structural Division, 106(12), 2527-2543.
[7]. Barone, M., Paquette, J., Resor, B., & Manuel, L.
(2012, January). Decades of wind turbine load simulation.
In 50th AIAA Aerospace Sciences Meeting including the
New Horizons Forum and Aerospace Exposition (p. 1288).
[8]. Dyrbye, C., & Hansen, S. O. (1996). Wind loads on
structures.
[9]. Whale, J., Anderson, C. G., Bareiss, R., & Wagner, S.
(2000). An experimental and numerical study of the vortex
structure in the wake of a wind turbine. Journal of Wind
Engineering and Industrial Aerodynamics, 84(1), 1-21.
[10]. Vickery, P. J., Lin, J., Skerlj, P. F., Twisdale Jr, L.
A., & Huang, K. (2006). HAZUS-MH hurricane model
methodology. I: Hurricane hazard, terrain, and wind load
modelling. Natural Hazards Review, 7(2), 82-93.
[11]. İstanbul Regulations for Wind Loads on Tall
Buildings, Version V, (August 2009)
[12]. Abaqus 6.11 Documentation User’s Manual Technol.
2010; 2, 16-21.
top related