PROJECT INFORMATION
Project NO.
Project Name Australia 7MW Skyline-54
Rev 0
ARCTECH SINGLE-AXIS TRACKER
Preliminary Calculation Report
2018/12/20---
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CONTENTS
1 SYSTEM OVERIVEW 2
2 CODE ANALYSIS 2
2.2 LOAD ASSUMPTION 2
3 LOAD ANALYSIS 3
3.1 DEAD LOAD ANALYSIS 3
3.2 WIND LOAD ANALYSIS 3
3.2.1 Wind Design Criteria 3
3.2.2 Equvilent Wind Speed of ASCE 7-10 3
3.2.3 Wind Stow Strategy 3
3.2.4 Aerolastic Analysis 3
3.2.5 Gust Effect Factor 4
3.2.6 Dynamic Analysis 4
3.3 WIND TUNNEL TEST ANALYSIS 4
3.4 SNOW LOAD ANALYSIS 5
3.4.1 Snow Stow Strategy 5
3.5 SEISMIC LOAD ANALYSIS 6
3.5.1 Horizontal Seismic Load Effect 6
3.5.2 Vertical Seismic Load Effect 6
4 COMPONENT ANALYSIS 7
4.1 TORQUE TUBE 7
4.2 SIMPLE POST 9
4.2.1 Equvilent C Channel Post 9
4.3 MOTOR POST 10
4.4 POST LOAD ON THE GOUND 10
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1 SYSTEM OVERVIEW
Panel Dimension 2000 * 992 mm
Panel Mass 22 kg
Number of Panels per Row Perimeter Rows 54
Interior Rows 54
Number of Posts per Row Perimeter Rows 9
Interior Rows 7
2 CODE ANALYSIS
Wind Map of Australia
Load Design Code AS-NZS 1170
Steel Design Code AISC 360 American Institute of Steel Construction
Cold Rolled Design Code AISI S100 American Iron and Steel Institute
Aluminum Design Code ADM Aluminum Design Manual
2.2 LOAD ASSUMPTION
Basic Wind Speed 41 m/s 148 km/h 91.7 mph
Basic Snow Load 0 psf
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3 LOAD ANALYSIS
3.1 DEAD LOAD ANAYSIS
Panel Mass 22 kg
Gravity 9.8 m/s^2
Panel Width 992 mm
Dead Load 217 N/m
Dead Torsional Load 32.6 N With 150mm eccentric distance
3.2 WIND LOAD ANALYSIS
3.2.1 Wind Design Criteria
Base on local building code AS-NZS 1170
Mz.cat 1 0.99
2 0.91
3 0.83
4 0.75
Mz.cat 0.91
Md 1 Any direction
Ms 1 Shielding multiplier
Mt 1 Topographic multiplier
VR 41 100year, 3s
Vsit 37.3 m/s
Vdes 37.3 m/s
Atab 77.5 m2
Ka 10 1
25 0.9
100 0.8
Ka 0.84
Kl 1
3.2.2 Equvilent wind speed of ASCE 7-10: 43.8 m/s
If the structure is calculated in ULS, for the equivalency, ArrowOne match the wind force according the local building
code. in ULS with the wind pressure that would be obtained following the ASCE 7.10 for ULS (note that it is equivalent
to talk about wind force and wind pressure as the force is the pressure multiplied by the exposed area)
3.2.3 Wind Stow Strategy
When the system integrated anemometer detects wind speeds higher than 18 m/s, the tracker will stow at 30 degrees
tilt. At this tilt all components are compliant at Code wind speed. For all other tilts, components were calculated with
a wind speed of 30 m/s.
Stow Tilt 30 deg 44 m/s Tornados were not taken into account and this
All Other Tilts(0~60deg) 30 m/s calculation report and corresponding structure
does not apply in such events
3.2.4 Aerolastic Analysis
The horizontal singe-axis tracker is a structure with a single
degree of freedom (one DoF). The torque tube is not 100%
rigid and will twist around its own axis when a torsional
moment is applied. ArrowOne calculates 50 different angular
rotations along the torque tube's length and applies all
torsional and pressure coefficients associated with each
rotation, through an iterative numerical process. The variable
sections of torque tube are obtained when there is
convergence within 1% between the torsional moments,
deflections and compliant cross-section.
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3.2.5 Gust Effect Factor
The code provides a Gust Effect Factor G = 0.85, which is for rigid structure. The tracker is not rigid enough to avoid
dynamic effects. In 3s-gust wind speed, 2 m (tracker width) is long enough to completely load the MWFRS. Then the
noncontemporaneous action of wind and resonant effects are negligible and ArrowOne consider the gust effect factor
G = 1.
3.2.6 Dynamic Analysis
When the wind moves over the array, it strikes and sweeps past all trackers in its path. In many instances, the forces
induced and the resulting responses of the structure must be considered. ArrowOne applies all Dynamic Amplification
Factors (DAFs) into the calculation.
3.3 WIND TUNNEL TEST ANALYSIS
CPP has evaluated wind loading on a generic array of Arctech's single-axis trackers through
wind tunnel tests". This analysis consists of simultaneous surface pressure measurements in
several locations distributed on the panel surface.
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3.4 SNOW LOAD ANALYSIS
3.4.1 Snow Stow Strategy
Arctech's tracker also includes a snow stow routine. When the snow sensor, which is mounted onto the weather
station, detects snow, the tracker will tilt at 60 degrees. At this tilt snow loads are not to be considered per code.
At 30 degrees (wind stow tilt) the all trackers components resist both max wind and snow loads.
Ground snow load 0 psf
Is 0.8 Snow importance factor
Ce 0.9 Exposure factor
Ct 1.2 Thermal factor
Case 1
Tilt 30 60 deg
p_f 0.00 0.00 psf 0.7*C_e*C_t*I_s*p_g
C_s 0.73 0.00 -0.018*Tilt/deg+1.273
p_s 0.00 0.00 psf C_s*p_f
p_balanced 0.00 0.00 psf p_s
p_balanced 0.00 0.00 Pa p_s
p_balanced 0 0 Pa p_s
mu_snow.bal 0 0 N/m p_balanced*L_x
Case 2
p_partial 0 0 Pa 0.5*p_s+0.25*p_s
c_partial 0 0 Pa 0.125*(p_s-0.5*p_s)
mu_snow.part 0 0 N/m p_partial*L_x
nu_My'.part 0 0 N c_partial*L_x^2
m_snow.seismic 0 0 kg/m p_s*L_x/g
mu.snow nu.snow seismic.snow
Case 1.1 0.0 0.0 0.0 30 balanced snow load
Case 1.2 0.0 0.0 0.0 30 partial snow load
Case 2.1 0.0 0.0 0.0 60 balanced snow load
Case 2.2 0.0 0.0 0.0 60 partial snow load
*According to ASCE 7-10, section 7.6.1, "For hip and gable roofs with a slope exceeding 30.2deg or with a
slope less than 2.38deg unbalanced snow loads are not required to be applied."
*According to ASCE 7-10, section 15.4.3, "W shall include snow and ice loads where there loads constitute
25% or more of W", when we calculate seismic load on the tracker.
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3.5 SEISMIC LOAD ANALYSIS
In this type of structures, wind loading is extensively higher than permanent loads. This means the effect of seismic
loads will not be dominant. However, it is still necessary to calculate their effect on the structure.
3.5.1 Horizontal Seismic Load Effect
S_s 0.5
S_1 0.2
F_a 1.4
F_v 2.0
S_MS 0.70
S_DS 0.47
S_M1 0.40
S_D1 0.27
Site Class D
Rho 1.3
R 1.0
I_e 1.0
C_s 0.47 *Seismic load will perform as 2 cases:
Case1 X+0.3Y+Z
Q_E 152 N/m Case2 0.3X+Y+Z
E_h 198 N/m
3.5.2 Vertical Seismic Load Effect
E_v 30.4 N/m
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4 COMPONENT ANALYSIS
4.1 TORQUE TUBE Perimeter Rows Result
Mid Torque Tube DT133x3.5-Q420
Inner Torque Tube DT133x3.5-Q420
Left Edge Torque Tube DT133x3.5-Q420
Right Edge Torque Tube DT133x3.5-Q420
Highest Stress Ratio 0.97 PASS
10
Torque Tube Perimeter-Shear(kN)
5
0
0 50 100 150 200 250 300 350
-5
-10
10
Torque Tube Bending Perimeter-Moment(kN*m)
5
0
0 50 100 150 200 250 300 350
-5
-10
-15
20
15
Torque Tube Perimeter-Torsion Moment(kN*m)
10
5
0
-5 0 50 100 150 200 250 300 350
-10
-15
-20
1.2
Torque Tube Perimeter-Stress Ratio(H3-6)
1
0.8
0.6
0.4
0.2
0
0 20 40 60 80 100
TT-PPM-Per 0U TT-PPM-Per 15U TT-PPM-Per 30U TT-PPM-Per 45U
TT-PPM-Per 60U TT-PPM-Per 0D TT-PPM-Per 15D TT-PPM-Per 30D
TT-PPM-Per 45D TT-PPM-Per 60D All bleow means OK
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4.1 TORQUE TUBE Interior Rows Result
Mid Torque Tube DT133x3.5-Q420
Inner Torque Tube DT133x3.5-Q420
Left Edge Torque Tube DT133x3.5-Q420
Right Edge Torque Tube DT133x3.5-Q420
Highest Stress Ratio 0.99 PASS
10
Torque Tube Interior-Shear(kN)
5
0
0 50 100 150 200 250 300 350
-5
-10
10
Torque Tube Interior-Moment(kN*m)
5
0
0 50 100 150 200 250 300 350
-5
-10
10
Torque Tube Interior-Torsion Moment(kN*m)
5
0
0 50 100 150 200 250 300 350
-5
-10
Torque Tube Interior-Stress Ratio(H3-6)
1.2
1
0.8
0.6
0.4
0.2
0
0 20 40 60 80 100
TT-PPM-Inter 0U TT-PPM-Inter 15U TT-PPM-Inter 30U TT-PPM-Inter 45U
TT-PPM-Inter 60U TT-PPM-Inter 0D TT-PPM-Inter 15D TT-PPM-Inter 30D
TT-PPM-Inter 45D TT-PPM-Inter 60D All bleow means OK
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4.2 SIMPLE POST Result
Inner Post H150x100x4.3x5.5-Q345
Perimeter Row
Edge Post H150x100x4.3x5.5-Q345 & H150x100x4.3x5.5-Q345
Inner Post H150x100x4.3x5.5-Q345
Interior Row
Edge Post H150x100x4.3x5.5-Q345 & H150x100x4.3x5.5-Q345
Highest Stress Ratio 0.99 PASS
1.2
Simple Post Perimeter-Stress Ratio(H1-1)
1
0.8
0.6
0.4
0.2
0
1 2 3 4 5 6 7 8 9 10
Post-PPM-Per 0U Post-PPM-Per 15U Post-PPM-Per 30U Post-PPM-Per 45U Post-PPM-Per 60U
Post-PPM-Per 0D Post-PPM-Per 15D Post-PPM-Per 30D All bleow means OK
Simple Post Interior-Stress Ratio(H1-1)
1.2
1
0.8
0.6
0.4
0.2
0
1 2 3 4 5 6 7 8 9 10
Post-PPM-Inter 0deg Post-PPM-Inter 10deg Post-PPM-Inter 15deg
Post-PPM-Inter 20deg Post-PPM-Inter 25deg Post-PPM-Inter 30deg
Post-PPM-Inter 45dedg Post-PPM-Inter 60deg All bleow means OK
4.2.1 Equvilent C Channel Post
I Beam-ASTM A6, Q345 C Channel, Q420
W6x7 H147x100x3.3x4.2 C150x100x40x3.0
W6x8.5 H148x100x4.3x4.9 C150x100x40x3.7
W6x9 H150x100x4.3x5.5 C150x100x40x4.0
W6x12 H153x100x5.8x7.1 C150x100x40x5.5
*The section may change due to corrosion rating.
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4.3 MOTOR POST Result
Perimeter Row H200x100x4.3x5.2-Q345
Interior Row H200x100x4.3x5.2-Q345
Highest Stress 0.81 PASS
1.2
Motor Post Perimeter-Stress Ratio
1
0.8
0.6
0.4
0.2
0
0deg 15deg 30deg 45deg 60deg 0deg 15deg 30deg 45deg 60deg
Motor Post Interior-Stress Ratio
1.2
0.8
0.6
0.4
0.2
0
0deg 15deg 30deg 45deg 60deg 0deg 15deg 30deg 45deg 60deg
4.4 POST LOAD ON THE GROUND
Motor Post
Perimeter Rows(kN)(kN*m) Interior Rows(kN)(kN*m)
Uplift Downforce Lateral Moment Uplift Downforce Lateral Moment
8.34 -12.93 6.63 29.37 8.76 -6.49 6.21 23.57
Simple Post
Perimeter Rows(kN)(kN*m) Interior Rows(kN)(kN*m)
Uplift Downforce Lateral Moment Uplift Downforce Lateral Moment
9.08 -11.71 10.49 15.18 8.38 -12.33 8.93 12.93
*The table is for reference only, for detail post load please contact us.
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